A comparative electrochemical study of non-enzymatic glucose, ascorbic acid, and albumin detection by using a ternary mesoporous metal oxide (ZrO2, SiO2and In2O3) modified graphene composite based biosensor

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A comparative electrochemical study of non-

enzymatic glucose, ascorbic acid, and albumin

detection by using a ternary mesoporous metal

oxide (ZrO , SiO and In O ) modiﬁed graphene

Cite this: RSC Adv., 2021, 11, 4256

2

2 3

composite based biosensor

Kamrun Nahar Fatema and Won-Chun Oh *^a^b

a

2 2

In this study, we present an electrochemical investigation of a ternary mesoporous metal oxide (ZrO , SiO

and In

in urine at physiological pH. Synergetic property of ZrO

via cyclic voltammetry (CV) using FTO glass and copper-foil electrodes with no prerequisite of solid antacid

expansion. The mesoporous ZrO –Ag–G–SiO and In –G–SiO composites were synthesized and

2

O

3

) modiﬁed graphene composite for non-enzymatic glucose, ascorbic acid, and albumin detection

2

–Ag–G–SiO and In –G–SiO were investigated

2

O

3

2

O

2 3

2

characterized using XRD, SEM, TEM, Raman spectroscopy, XPS, DRS, BET, and photocurrent

measurements. Upon increasing the glucose concentration from 0 to 3 mM, CV results indicated two

3+

4+

anodic peaks at +0.18 V and +0.42 V versus Ag/AgCl, corresponding to Zr and Zr , respectively,

considering the presence of glucose in urine. Moreover, the eﬀects of high surface area In –G–SiO

were observed upon the examination of ZrO –Ag–G–SiO . In –G–SiO demonstrated a decent

electrochemical pattern in glucose, ascorbic acid, and albumin sensing. Nevertheless, insigniﬁcant

synergistic eﬀects were observed in In -G, ZrO -G, and ZrO –G–SiO . In –G–SiO performed well

O

2 3

2

O

3

2

Received 21st November 2020

Accepted 15th December 2020

2

O

3

2

O

3

2

DOI: 10.1039/d0ra09886h

under a wide range of electrolytes and urine, and showed no activity toward uric acid, suggesting

potential for biodetection in urine.

rsc.li/rsc-advances

of the metal and glucose. Accordingly, a diﬀerence in the

oxidation state of glucose molecules adsorbed onto the metal

1

. Introduction

Diabetes mellitus has become a universally critical health surface leads to a diﬀerence in the metal–glucose complex,

challenge that has caused other non-transferable sicknesses lowering the quality of the glucose–metal bond and in turn

6

–8

and complications such as cardiovascular illness, stroke, and lowering the desorption rate of glucose molecules.

The

1

chronic kidney failure. Non-obtrusive glucose and micro- impersonating cycle of metals and metal oxides, such as Au, Cu,

albumin estimation has largely improved the treatment viability Pt, Ni etc., have been accounted by the direct electrochemical

9

–18

and preventive measures. For simple glucose level determina- oxidation of glucose and electron move. Among these metals,

tion, an assessment of glucose in urine can be a decent ZrO

2

based substrates have been considered as the best because

marker, as glucose is released in the body because of kidney of their ease of production, high strength, and excellent syner-

failure, endocrine issues, and hyperglycemia. Recent improve- gistic properties. ZrO is one of the metal oxides with oxidizable

ments in non-enzymatic glucose detection has overcome the and reducible sites. ZrO is an n-type semiconductor with

restrictions of traditional chemical-based glucose sensors, a bandgap of 5.12 eV. Subsequently, the modication of ZrO

2–5

2

1

9

2

inuenced by humidity, pH, protein denaturation, poor repro- with other supporting materials, such as graphene oxide and/or

6

ducibility, and signicant manufacturing cost. According to another p-type semiconductor, is a promising way to achieve the

7

Pletcher, the working of a non-enzymatic glucose sensor above-mentioned objectives, particularly enhancing its syner-

involves the chemisorption of hydroxyl ions onto a metal gistic properties.

substrate, permitting a bond formation between the d-electrons

Graphene-based metal oxide materials have remarkable

applications in various elds. Furthermore, the oxygen-

containing-functional groups of graphene oxide act as a stabi-

lizer for the metal-nanoparticles and prevent their aggregation.

However, despite the high reaction kinetics and electron

transfer, activity in highly alkaline conditions is insignicant

for the vast majority of physiological samples. A powerful

a

Department of Advanced Materials Science & Engineering, Hanseo University,

Seosan-si, Chungnam, Korea, 356-706. E-mail: wc_oh@hanseo.ac.kr; Fax: +82-41-

6

88-3352; Tel: +82-41-660-1337

b

College of Materials Science and Engineering, Anhui University of Science

Technology, Huainan 232001, PR China

&

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technique for enhancing the performance of graphene is to

2.1.1 Synthesis of graphene oxide. A modied Hummers'

improve the electron-donating capacity, charge/discharge method was used to synthesize graphene oxide by the oxidation

20

28

capacity, and resistance of graphene.

of graphite powder. 15 g common graphite and sulfuric acid

Mesoporous silica, made of silica aerogel, has been used as (450 mL, H SO ) were added to de-ionized water and stirred for

2

4

ꢁ

a substrate material, adsorbent, and thermal insulator. In the an hour at 0 C in an ice bath. Aer 1 h, the ice bath was

eld of catalysis, it can provide a high density of surface area to removed and potassium permanganate (45 g, KMnO ) was



4

21

be used as an adsorbent. The main reason for the progress of slowly added to the mixture (graphite + H SO ) and stirred

graphene-based metal oxide photocatalysts is that carbon continuously at 35 C until the color of the mixture changed to

material (graphene) can inuence the rate at which photo- gray. The reaction vessel was xed and maintained at 100 C

2

4

ꢁ

generated electrons relocate from the metal oxide to graphene while stirring for 30 min. Hydrogen peroxide (H O ) was then

2

22

and reduce the electron–hole recombination. The combina- added dropwise over 5 min. The mixture was washed with

tion of the stability of ZrO₂and high-surface area of meso- (CH ) CO and hydrochloric acid (HCl, 10%) a few times, and

3 2

ꢁ

porous SiO

kinetics.

2

with graphene can lead to enhanced reaction then heated in an oven at 90 C for 12 h until it turned into

graphite oxide powder. The as-obtained graphite oxide powder

Ascorbic acid (AA, nutrient C) is an exceptionally huge was added to 200 mL de-ionized water, thoroughly stirred for

bioactive compound and a water-soluble nutrient that cannot 30 min, and then ultrasonicated for 2 h (using Ultrasonic

be synthesized by the human body, and should, therefore, be Processor, VCX 750). Finally, the mixture was ltered and

introduced through daily diet. Ascorbic acid is added to a few washed with warm water a few times, and then placed in the

23

drug formulations to boost injury recovery and to prevent or oven for 6 h to form graphene oxide powder.

2

4

25

cure some diseases, such as scurvy, normal cold, and

2

2.1.2. Synthesis of ZrO . 6 g Pluronic F127 was poured into

26

hyphema. Moreover, AA is the most unstable nutrient in food, 30 mL of anhydrous ethanol to make mixture A. Then, 30 mL of

especially products of the soil, and its decomposition leads to zirconium(IV) propoxide mixture was blended with 30 mL

a decline in the wholesome food quality. Accordingly, mixture of ethanol and ethylene glycol, used as a stabilizer, to

a detection strategy that allows a fast, simple, and sensitive make mixture B with vigorous stirring. Mixtures A and B were

27

ꢁ

detection of AA would be signicant in various elds, especially combined and mixed under 40 C, followed by the dropwise

in medicine and the food industry.

addition of 20 mL of de-ionized water. A suitable volume of

In this work, we studied mesoporous ZrO –Ag–G–SiO and hydrochloric acid was added to adjust the pH to 2.4, and the

2

ꢁ

In O –G–SiO substrates without precedent for non-commercial mixture was stirred at 40 C for 1 h. The subsequent mixture was

2

3

2

ꢁ

urine and PBS. We carried out experiments to determine the kept at 40–80 C in a closed compartment for 24 h until it

direct correlation of the electrocatalytic characteristics of ZrO

Ag–G–SiO and In –G–SiO

using FTO glass and copper foil electrodes via cyclic voltam- electric oven. The as-synthesized materials were then calcined

2

–

formed a gel. The precipitate was ltered through a Whatman

ꢁ

2

O

3

2

. The analyses were performed lter paper (F ¼ 110 mm), and further dried at 100 C in an

ꢁ

metry (CV) to obtain the reaction mechanism. Moreover, the at 400 C for 4 h to remove the template. To evaluate the thermal

eﬀects of carbon framework, such as graphene (G), on ZrO and stability, the samples without the template were calcined in air

2

ꢁ

In O were assessed in both basic and neutral pH conditions. at a temperature of 600 C for 4 h.

2

3

Also, the morphological, physical, and chemical properties of

2

2.1.3. Combining GO with ZrO . 0.333 g of GO was

ZrO

2

–Ag–G–SiO

2

and In

2

O

3

–G–SiO

2

were studied. In general, dispersed in 200 mL of de-ionized water and exposed to soni-

2

O

3

–G–SiO

2

exhibited an excellent cation (amp ¼ 70%, power ¼ 840 Watt) for 30 min to make

performance in inert media without any electron donor, indi- mixture C. Meanwhile, ZrO was dissolved to make mixture D

2

cating further progress for basic glucose, albumin, and ascorbic through vigorous mixing; then, this mixture was mixed with C.

acid determination in urine.

31.5 mL of 1 M sodium hydroxide (NaOH) was added dropwise

into the sonicated precursor to create an ideal pH. The resultant

mixture was stirred for 1 h under 100 C until the mixture color

ꢁ

2. Experimental section

changed to black, and this modication led to the successful

2.1. Materials

2

combination of GO with ZrO to form mixture E.

All chemical reagents of analytical grade were used without

2.1.4. Combining SiO₂with G-ZrO . 1.0 g of triblock

2

further purication. Graphite powder akes (>99.99 wt%), zir- copolymer Pluronic F-127 was added to 15 mL of deionized

ꢁ

conium(IV) propoxide (C12

H

28

O

4

Zr, 70 wt% in 1- propanol), and water and 60 mL (2 M) HCl and stirred at 40 C until the

Pluronic F127 (EO106PO70EO106) were procured from Sigma- copolymer was completely dissolved. 3.20 g of tetraethyl ortho-

Aldrich; InCl

3

indium(III) chloride, urea, SDBS – sodium silicate (TEOS) was added and the solution was stirred for 12 h

ꢁ

dodecyl benzene sulphonate, and tetraethyl orthosilicate at 40 C. The mixture was transferred into a 100 mL capacity

ꢁ

(TEOS, Acros Organics) were procured from Samchun Pure stainless steel-lined autoclave and kept at 100 C in the

2 6 2

Chemical Co Ltd. Ethylene glycol (C H O , 99.5%) was container for 20 h. The subsequent white precipitate was

purchased from Duksan Pure Chemicals Co. Ltd., Korea; separated through a Whatman lter paper (F ¼ 110 mm),

hydrochloric acid (HCl) was purchased from Dae-Jung Chemical washed with de-ionized water and ethanol a few times, and then

ꢀ

1

ꢁ

Co. Ltd., Korea. Deionized water (18.2 MU cm ) was used in all dried under vacuum at 65 C overnight. Finally, the powder was

the experiments.

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ꢁ

calcined in air at 550 C for 3 h to eliminate the copolymer. of the samples were obtained using a Hitachi H9500 operated at

Mixture E was added dropwise into a 100 mL round-bottom 300 kV. Raman spectroscopy was performed using a confocal

ꢁ



ask containing 0.3 g of silica powder and stirred at 100

C

Raman imaging system with a 633 nm excitation laser

for 24 h. Aer 24 h, ultrasonication (amp ¼ 70%, power ¼ 840 (Renishaw inVia Reex). The surface composition was analyzed

Watt) was carried out for 1 h, aer which the mixture was via X-ray photoelectron spectroscopy (SHIMADZU, KRATOS



ltered, washed with 1 mL of methanol, and dried under AXIS SUPRA) with a monochromatized Al Ka X-ray source (10

ꢁ

vacuum at 65 C overnight. The furnace temperature was kV, 1500 W, pass energy ¼ 40 eV). UV-vis diﬀuse reectance

ꢁ

ꢀ1

ꢁ

increased to 700 C at a rate of 10 C min and held at 700 C spectroscopy (DRS) was performed using an ultraviolet-visible

for 4 h. Finally, the furnace was gradually cooled to room (UV-vis) spectrophotometer (SHIMADZU UV-2600) ranging

ꢁ

temperature (RT; +25 C), and the color of the nal product was from 200 to 800 nm. The bandgap energies of the photocatalysts

dark brown or black.

were calculated through the application of a modied Kubelka–

2

.1.5 Mesoporous silica synthesis with In O –GO. 1.0 g of Munk function obtained from the UV-vis DRS data. Nitrogen

2

3

triblock copolymer Pluronic P-127 surfactant (Aldrich) was added adsorption/desorption isotherms were analyzed by Micro Active

to a reaction vessel containing 15 g of deionized water and 60 g of for ASAP 2460, the specic surface area was calculated by the

ꢁ

2

M HCl at 40 C and then stirred until the copolymer was Brunauer–Emmett–Teller (BET) method, and pore-size distri-

completely dissolved. 3.20 g of tetraethyl orthosilicate (TEOS, Acros bution was evaluated according to the Barrett–Joyner–Halenda

ꢁ

Organics) was added and stirred for 12 h at 40 C. The mixture was (BJH) method. Photoluminescence spectra (PL) were obtained

ꢁ

heated to 100 C in an oven for 20 h. The subsequent white by a uorescence spectrophotometer (Hitachi F-7000) with an

precipitate was ltered, washed with water and ethanol, and dried emission wavelength region of 280–500 nm at RT.

ꢁ

at 65 C in a short period. Finally, the copolymer was eliminated by

ꢁ

calcination in air at 550 C for 3 h. The combined mesoporous

2

.3 Electrode preparation and measurements

In –G–SiO and ZrO –Ag–G–SiO thin lms were prepared using

a conventional atomic layer deposition technique. In O , IG,

In

followed by the addition of GO water suspension comparative with

the amount of incorporated mesoporous In nanoparticles in

2 3

O nanoparticles were dispersed in 7 mL of deionized water,

2

O

3

2

29

2

3

2 3

O

mesoporous IGS10, and IGS20 individually were ground with ethyl

cellulose and PVDF in an agate mortar to form a gas detecting

paste. The paste was coated on a substrate by applying a physical

coating method and it is important that the paste evenly applied

on the surface. The as-prepared coated-substrate put into an

the mixture. GO was obtained from graphite akes by using the

Hummers' method. The combined mesoporous In O nano-

2

3

particles were scattered in 7 mL of deionized water, followed by the

addition of GO water suspension comparative with the amount of

incorporated mesoporous In

mixture was ultra-sonicated for 20 min, and the In

2

O

3

nanoparticles in the mixture. The

–GO mixture

ꢁ

electric oven and dried at 100 C for 3 h. The paste was coated

2 3

O

manually via a physical coating method. The thickness of the

coating was 0.1, 0.3, and 0.5 mm, and all the samples had uniform

thickness and measurements. An electrochemical cell was used in

voltammetry with three electrodes: a working electrode (WE),

reference electrode (RE), counter electrode (CE). A cyclic low

potential excitation signal was applied between the working elec-

trode and the reference electrode and the current owing between

the working and reference electrodes was estimated. The current

peaks were obtained at a specic voltage region, due to the specic

redox potentials running on the working terminal. The reference

electrode was used for the analysis of the Cyclic Voltammetry (CV).

The signal conditioning stage applied time-dependent potential

between the working and reference electrodes, and converted the

current owing between the working and reference electrodes into

a voltage signal.

was added dropwise to a 100 mL round-bottom ask containing

silica powder in two diﬀerent proportion, 10% and 20%. Aer

mixing for 48 h, the powder was ltered, washed with 1 mL of

ꢁ

methanol, and dried at 70 C in a short period. The furnace

ꢁ

ꢀ1

temperature was increased to 700 C at a rate of 10 C min and

ꢁ

held at 700 C for 4 h. Finally, the furnace was gradually cooled to

room temperature. A light yellow colored product was obtained.

2.2. Characterization

The phases of the samples were examined using X-ray diﬀrac-

tion measurements (SHIMADZU XRD-6000) equipped with a Cu

˚

Ka X-ray source (1.5406 A). The Debye–Scherrer equation (eqn

(

2 2

1)) was used to determine the particle size of ZrO and SiO ,

17

based on the data acquired via XRD analysis.

L ¼ Kl/(FWHM)cos q; [d ¼ 0.9l/b cos q]

(1)

3

. Result and discussion

where L is the particle size, l is the wavelength of X-ray radiation

1.5406 A), b is the full width at half maximum (FWHM) of the

3.1. Material characterizations

˚

(

peak (in radians), and 2q is the Bragg angle. The shape and Fig. 1 shows the XRD patterns of ZrO

structure of the nanomaterial surface were analyzed using GO–SiO nanocomposites, and the pattern essentially shows the

high-resolution SEM (TESCAN, MAIA3). The chemical structural phases of all materials studied. The main (green

composition was analyzed using energy dispersive X-ray (EDX) colored) peak presents the XRD pattern of ZrO –GO nano-

analysis in combination with SEM. Transmission electron composites, which correspond to the two crystalline phases,

2 2 2

–GO, GO–SiO , and ZrO –

2

a

2

˚

microscopy (TEM, Hitachi HT7700, operated at 100 kV) was monoclinic (a ¼ 5.1477 A, b ¼ 5.2096 A, c ¼ 5.3164 A) and

˚

used to analyze the morphologies of the samples. High- tetragonal (a ¼ 3.5781 A, c ¼ 5.1623 A), and the reference

18

resolution transmission electron microscopy (HRTEM) images numbers are JCPDS no. 78-0047, and no. 88-1007. The peaks

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Fig. 1 XRD patterns of (a) In

2 3

O

–GO, (b) G-SiO

2

, (c) Zr–G–SiO

2

(d) In

2

O –GO–SiO

3

2

, (e) Zr–Ag–G–SiO

2

.

Fig. 2 SEM images of (a) In

2

O

3

–GO, (b) G-SiO

2

, (c) Zr–G–SiO

2

(d) In

2 3

O

–GO–SiO

2

, (e) Zr–Ag–G–SiO

2

.

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ꢁ

were located at 30.63, 35.49, 50.84, 60.46 2q assigned to the investigation of the consequent GO–SiO

2 2

and ZrO –GO double

(

002), (101), (102), and (103) planes, respectively, and this result composite, the unpredictable 3D cubic ZrO and spherical SiO₂

2

suggested a base-centered monoclinic structured ZrO . And the were consistently dispersed onto the graphene surface. The

2

other diﬀraction peaks corresponded to the tetragonal struc- normal particle size of ZrO was 55.04 nm, and the diameter of

2

19

tured ZrO

monoclinic was 7 : 3. The subsequent pattern (orange colored) oxide and silica oxide completely covered the whole surface of

presents the XRD data of GO–SiO nanocomposites; this pattern graphene. The primary oxide compound shape was not

2 2

. The diﬀraction peak ratio between tetragonal and SiO was 280.21 nm. Fig. 2(e) shows that the growth of metal

2

demonstrated a sharp and wide peak, which was situated at a 2q changed; however, the size of silica oxide was diminished aer

ꢁ

of 26.62 . The last pattern (wine colored) presents the XRD of adsorption onto the graphene surface. The principle function of

the ternary ZrO –GO–SiO composite. All the characteristic graphene was to provide suﬃcient area of nanocomposite that

2

peaks were present, which were allocated to ZrO , SiO , and can be developed and spread (attached) on the surface during

2

graphene. Also, the XRD pattern of the ternary composite had the combination cycle. Moreover, graphene forms a covalent

a new peak, implying that ZrO and mesoporous SiO undergo bond with the precursors through oxygen-containing functional

2

slight structural changes to give another XRD peak. The XRD groups. The results of SEM demonstrated the diﬀerences

pattern of the binary composite did not show the diﬀraction between the paired and ternary composite.

peaks of the graphitic material because of the exceptionally low

amounts. Furthermore, the XRD results aﬃrmed that meso- of a ternary (ZrO

Fig. 3 presents the consequent laboratory-scale examination

–GO–SiO ) composite, which uncovers the

2

porous SiO₂is eﬀectively attached to GO and ZrO₂nano- fundamental components, in particular C, O, Zr, and Si. The

composite; additionally, the arrangement strategy is component of C was obtained from graphene. Zr and Si are the

demonstrated to be the best possible combination cycle of the fundamental components in ZrO and SiO . The nuclear and

2

material. We used the Debye–Scherrer formula to assess the weight amounts of oxygen were high due to the ternary

crystallite size of ZrO

be 72 and 15 nm, respectively.

2

and SiO

2

particles and discovered them to composite comprising of an oxide segment and graphene oxide.

Also, a few peaks were seen in the EDX spectra because of a part

Fig. 2 presents the overall morphology of the as-obtained of the precursor material and contamination from the machine.

binary and ternary composites investigated through SEM The shape and morphology of the binary and ternary compos-

examination. As shown in Fig. 2(a, b) and (c–e), from the SEM ites were observed and examined using TEM and HRTEM, and

2 3 2 2

Fig. 3 EDS of (a) In O –GO–SiO and (b) Zr–Ag–G–SiO samples.

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Fig. 4 TEM images (A) of (a) In

2 3

O

–GO, (b) G-SiO

2

, (c) Zr–G–SiO

2

(d) In

2

O

3 2 2

–GO–SiO , (e) Zr–Ag–G–SiO . HRTEM images (B) and SAED pattern

(

2 3 2 2

B) of In O –GO–SiO (a1 and a2) and Zr–Ag–G–SiO (b1 and b2) nanocomposites, respectively.

Fig. 4(A) shows images with diﬀerent magnications. The metal shown in Fig. 4(c) and (d). The silica oxide nanocomposites were

oxide (ZrO ) nanocomposite appeared as a dark spot in Fig. 4(a) agglomerated on the surface of graphene. The silica and

and (b). Silica oxide (SiO ) was round, and was dull colored, as modied metal oxide nanocomposites were surrounded by

2

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2 3 2 2 2 3 2 2 2 3 2

Fig. 5 Raman spectra of (a) In O –GO, G-SiO , Zr–G–SiO , In O –GO–SiO , Zr–Ag–G–SiO . (b) Photocurrent density of In O –GO–SiO , Zr–

Ag–G–SiO .

2

graphene, and it appeared as a light dark shaded region. For corresponding to In O –GO–SiO (211), (222), and (400), and Zr–

2

3

2

a high-magnication HRTEM, Fig. 4B(a2) shows In

2

O

3

–GO–SiO

2

Ag–G–SiO , (112), (103) and (202), respectively. The calculation

nanoparticles, and glass-like cross-section borders with the d- of interplanar spacing depends on the structural phase of the

˚

dispersing of 0.29 A compared to In

2

O

3

(222); (b2) shows Zr– material. If the interplanar spacing (d spacing) is reduced, the

Ag–G–SiO

2

translucent grid borders with the d-separating of planes (hkl) are expanded.

Raman spectroscopy is a light scattering technique, where

˚

0

.462 A nm, relating to (202). Further details of the translucent

grid were observed in selected area electron diﬀraction (SAED) the laser light interacts with sub-atomic vibrations and photons

examination, as shown in Fig. 4B(b1) and (b2). The patterns bringing about a change in the energy, either increase or

uncover three concentric diﬀraction rings from the centre decrease, of the laser photons. The results of Raman

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spectroscopy provide data on the electronic band structure of (D graphene because of the solid scattering properties, as shown in

and G band) carbon materials, phases and fundamental prop- Fig. 5. Zirconium oxide (ZrO ) has three diﬀerent crystalline

2

erties of the spherical phase of SiO , cubic phase of ZrO , and phases, (a) monoclinic 18 (9A + 9B ), (b) tetragonal 6 (1A

+

2

g

1g

20

2

B₁_g+ 3E ), and (c) cubic 3 (T ) vibrational modes. The ZrO₂

g 2g

peak (green colored) was located in the wavelength range of

ꢀ

1

00–800 cm . The vibrational modes of the monoclinic phase

ꢀ1

were allocated as follows: A

g

at 177, 333, 346, 476 cm , B

g

at 501,

ꢀ1

6

37, 756 cm , and the shis at 476 and 637 cm belong to the

21

biphasic structure. The GO–SiO

2

binary composite exhibited 3

unique peaks (orange colored), which appeared at wavelengths of

ꢀ

1

5

10, 1363, and 1590 cm . The wide and low-intensity peak was

ꢀ1

situated at a wavelength of 510 cm , which corresponds to the

spherical structure of SiO , while the other two peaks were allo-

cated to the D and G-band of graphene. As a rule, the D-band was

at the wavelength of 1390 cm and the G-band was at around

583 cm because of the E2g mode of graphene. The peak

2

ꢀ

1

ꢀ

1

22

1

properties of the D and G bands (position, intensity, and width) are

used for characterizing material composition. In the Raman

ꢀ

1

spectrum of GO–SiO , the main peak appeared at 1363 cm and

2

3

the peak can be attributed to the ordinary sp hybridized carbon (D

band) auxiliary defect, while the subsequent peak can be attributed

2

to the in-plane vibration of sp hybridized carbons (G band) that

ꢀ1

was located at 1590 cm (graphite), and can be used to charac-

terize the arrangement of the electronic structure of graphene. The

2 2

Raman spectrum of ZrO –GO–SiO with the characteristic peaks of

graphene were observed, while the peaks of SiO and ZrO were not

2

ꢀ1

ꢀ

1

present. Peaks appeared at 1370 cm and 1597 cm Raman

wavelengths, and the peak intensity was lower than the intensity of

the D and G-groups. In the consequent Raman spectrum, the

position of the D and G-band was changed, which was expected of

2 2

the SiO and ZrO attached to the surface of graphene, implying

that the composition of graphene was changed. The intensity of

the D-band was lower than that of the G-band, implying that there

2

3

2

were more sp bonds and more change from sp to sp . Besides,

3

2

the intensity ratio of I_D/I_Gdetermined the sp /sp proportion of

graphene, and the value was 1.04. Fig. 5(b) shows the photo-

current response of the ternary composite during four on–oﬀ

cycles of light illumination. Generally, the ternary composite

showed rapid and high-velocity current response for each light

28

irradiation. This shows the improvement of the high sensing

activity of the ternary composite.

The N adsorption–desorption isotherms were examined at

2

77 K for the as-obtained binary and ternary composites, as

shown in Fig. 6. The surface area and pore-size distribution

were assessed by BET and BJH methods, respectively. The

Table 1 Surface properties of the obtained In

SiO , G-SiO , Zr–G–SiO and Zr–Ag–G–SiO

2 3 2 3

O –GO, In O –GO–

2

BET surface area Total pore volume Average Pore

2

ꢀ1

3

ꢀ1

Samples

(m g

)

(cm g

)

diameter (nm)

In

2

O

3

–GO

–GO–SiO

29.688

253.79

33.250

106.205

9.1703

0.105

0.281

0.145

0.123

13.995

4.4284

14.213

5.6691

8.9632

2

3

2

GO–SiO

–GO, Zr–G–SiO

Zr–Ag–G–SiO

2

Fig. 6 Nitrogen adsorption–desorption isotherms of (a) In

2

O

3

2

(

b) G-SiO

2

, (c) Zr–G–SiO

2

(d) In

2

O

3 2

–GO–SiO , (e) Zr–Ag–G–SiO

2

.

2

0.020549

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results are shown in Fig. 6, while the summarized information isotherm (nonporous or macroporous), while the relationship

is presented in Table 1. The overall weight of the hysteresis between the pore shape and the adsorption–desorption

loops was (0.4–1.0) P/P , as shown in Fig. 6(a). The adsorption isotherm indicate H3 hysteresis. The type H3 hysteresis loop

0

isotherm of ZrO –GO binary composite corresponds to type II indicates or corresponds to a slit-like pore. The GO–SiO binary

2

2 3 2 2 2

Fig. 7 XPS spectra of (a) In O –GO–SiO , (b) Zr–Ag–G–SiO , (c) Zr–G–SiO .

4264 | RSC Adv., 2021, 11, 4256–4269

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composite was identied with type IV isotherm with type H1

hysteresis loop. The adsorption isotherm of ZrO –GO–SiO

2

ternary composite exhibited type IV isotherm with type H1

hysteresis loop. The type IV isotherm is normal for mesoporous

2

7

adsorbents.

The ternary ZrO

2

–GO–SiO

2

composite has

ꢀ1

a greater surface area, 106.205 m g , while the normal pore

2 2

breadth was 5.4 nm. The spherical SiO attached to ZrO –GO

because of the improved value of the specic surface area and

the experimental conditions, particularly the calcination

temperature. The obtained ternary composite had a high

specic surface area and approximately small pores, which

exhibit high synergy between the environment of the composite

and color material during the degradation cycle. The excellent

performance of these mesoporous materials was attributed to

a high surface area, tunable pore size, and increased number of

active sites of the nano-sized substrate material. High surface

area and mesoporosity are directly related to the high adsorp-

tion capacity of sensing materials. The hysteresis loops gradu-

ally shi to a higher relative pressure (P/P ) for In O –GO–SiO

2

0

2

3

and ZrO –GO–SiO₂suggesting that these mesopores were

2

expanding the mesoporous SiO

Fig. 7(a) shows the XPS spectra which conrmed the interac-

tion between ZrO , SiO , and graphene. XPS investigation was

performed over ternary ZrO –GO–SiO composite. Fig. 7(b) shows

2

.

2

the XPS spectrum of O 1s, where the peak is at a binding energy of

around 531 eV; the peak can be attributed to metal oxide ions; on

the other hand, if the binding energy of the peak is higher than

23

5

31 eV, it corresponds to hydroxide ions. In the XPS spectrum of

O 1s, the wide peak was located at 530.79 eV, and the binding

energy was lower than 531 eV, demonstrating the type of metal

oxide. Fig. 7(c) presents the XPS spectrum of C 1s showing three

peaks that were located at the binding energy values of 284.63,

285.65 and 288.38 eV. The XPS spectrum of C 1s comprises few

characteristic peaks, such as carbonyl carbon (C]O, (288.4–288.6)

eV), aliphatic (C–C, (284.4–285.9) eV), Zr–O–C ((286.6–286.8) eV),

24

and carboxylate carbon (O–C]O, 289.3 eV). The (C–C) and (C–C)

bonds indicate the carbon-to-carbon chemical bonding sate, and

C–OX (X ¼ metal) bond indicates the metal-to-carbon chemical

bonding state. Fig. 7(d) shows the XPS spectrum of Zr 3d

comprising two sharp peaks. These two peaks were located at

binding energy values of 181.98 and 184.34 eV, attributed to the

spin orbital type of Zr 3d and Zr 3d₃_/₂, and this result is the proof

5/2

25

of Zr(4 ꢀ x) particles. The XPS peaks of Si2p appeared at 101.60

eV binding energy region in Fig. 7(e) and this peak assigned to the

presence of O–Si-O. The spins-orbital were not included in the XPS

26

analysis due to peak distortion. The binding energy shis show

the strong bonding between in ZrO –GO–SiO

2

.

3.2. Electrochemical response of ZrO

2 2

–Ag–G–SiO and

In O –G–SiO

2

3

2

Fig. 8(a) demonstrates the electrochemical properties of ZrO

Ag–G–SiO and In –G–SiO , the CV curves of diﬀerent elec-

trodes with uncovered In O –G, G–SiO , ZrO –G–SiO , ZrO –Ag–

2

–

Fig. 8 (a) Cyclic voltammograms of In

In –GO–SiO , Zr–Ag–G–SiO in PBS. (b) In

G–SiO with glucose, (c) with ascorbic acid and (d) with albumin.

2

O

3

–GO, G-SiO

2

, Zr–G–SiO

2

,

2

O

3

2

O

2 3

2

O

3

–GO–SiO

2

, Zr–Ag–

2

3

2

1

2

G–SiO and In O –G–SiO electrode in 0.2 M PBS (pH 7.0).

2

3

2

4

Fig. 8(b) shows that, in contrast with the absence of glucose, the

increase in the oxidation current due to the increase in glucose

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2 3

Fig. 9 (a) Concentration dependency of In O –GO with glucose, (b) with ascorbic acid (c) albumin.

concentration occurred on account of ZrO

In –G–SiO . Fig. 8(c) shows the oxidation current of AA, ZrO

Ag–G–SiO and In –G–SiO display a veried increment at be due to its synergistic eﬀect and higher electrochemically

.1 V while the other three anodes showed a slight change in the active surface area compared to other anodes. The mesoporous

2

–Ag–G–SiO

2

and studied low potential range containing 1.0 mM AA. The

2

O

3

2

–

enhanced electrocatalytic performance of In –G–SiO might

2

O

3

2

O

3

2

0

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Fig. 10 (a) The electrochemical response of the presented sensor in 0.2 M PBS at diﬀerent pH. (b) Selectivity of the sensor.

2 3 2 2

structure of spherical In O –G–SiO can provide a large active G–SiO show expanding oxidation current patterns with respect

area for the oxidation state of glucose and AA and the structure to increasing glucose concentration from 0 to 3 mM in PBS.

can improve the mass exchange. In Fig. 8(d), the oxidation

current at ZrO –Ag–G–SiO and In O –G–SiO show a signi-

cant decline at 0.1 V in the presence of albumin.

2

3

2

3

.3. Catalytic performance and detection mechanism in

physiological pH

For more information on synergistic activity, clinically

negative control urine was used to assess non-enzymatic elec- To enhance the electrochemical reaction of In O –G–SiO for

2

3

2

trochemical sensitivity to glucose. Fig. 9 shows the concentra- glucose, AA and microalbumin detection, the eﬀect of pH on the

tion dependency of In –GO with glucose, ascorbic acid and electrode reaction was studied by CV in 0.2 M PBS containing

albumin. Fig. 9 shows an oxidation current decreasing from 0 to 1.0 mM Glucose, AA and microalbumin at various pH. A

.8 V, which indicates that the oxidation current expands signicant increase in the current signal was observed with the

slightly in In O -G-SiO , which strengthens the egg white and increase in pH and showed the best performance at pH 7.0

2 3

O

0

2

3

2

has less reactivity. Fig. 10(a) and (b) show pH dependency of (Fig. 10(a)). The result likewise shows that AA can be detected at

In O –G–SiO in PBS. In Fig. 10(a) and (b), both curves of In O – diﬀerent pH. This might be credited to the excellent stability of

2

3

2

2 3

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3

+

4+

ꢀ

the incorporated In

2

O

3

–G–SiO

2

, which may enhance the

2In 4 2In + 2e

(2)

capacity to oppose the external condition. Furthermore, since

the electrode materials are altogether inorganic materials, in

contrast to the organic catalysts, they are less aﬀected by the

external condition. To maintain the physiological condition and

acquire high sensitivity, pH 7.0 PBS was chosen for further

experiments.

4

In + C

+

3+

6

H

12

O

6

(glucose) 4 2In

+

+ C

6

H

10

O

6

(gluconolactone) + 2H

(3)

4

. Conclusions

3

.4 Interference

In this study, we prepared mesoporous ZrO –GO–SiO₂and

In O –G–SiO materials and evaluated their performance for

2

To assess the selectivity of In O –G–SiO , we studied the eﬀect

2

3

2

3

2

of various interfering ions and organic molecules in the elec-

trochemical trials (Fig. 9(b)). No interference was observed for

starch, KCl, albumin, UA, urea, glucose, and NaCl when their

concentrations were multiple times higher than that of AA (0.2

mM). The high selectivity could be due to the superimposed

active sites of the incorporated electrode having a strong

synergistic eﬀect on the oxidative dehydrogenation of ascorbic

acid and glucose, and furthermore, mostly in light of the fact

glucose, ascorbic acid, and albumin detection in the concen-

tration range from 0 to 3 mM. With the necessity of a strong

alkaline condition, In O –G–SiO with high surface area and

2 3 2

adsorption capacity demonstrated a comparable performance

for electrochemical reactions using cyclic voltammetry. The

3+

4+

both direct synergistic oxidation of the In /Co oxidation-

oxide pair and manual oxidation were studied by measuring

glucose. In view of the results, In O –G–SiO exhibited excellent

2

3

2

2 3 2

that In O –G–SiO coordinated electrode has no obvious reac-

tant eﬀect on the expected interfering substances in dietary

items or other organic samples. The results show the interfer-

sensitivity in urine, recommending practical application for

glucose estimation in urine.

2 3 2

ence capacity of In O –G–SiO .

Conﬂicts of interest

3.5 Reproducibility and stability of the developed sensor

There are no conict to declare.

The reproducibility of the sensor was also explored for three

estimations with increasing glucose, AA, and albumin concen- Acknowledgements

tration. The relative standard deviation (RSD) of the current

signal for 1.0 mM AA was under 2%. When In O –G–SiO was

2 3 2

stored at room temperature for 30 days, it showed that the

current reaction to 1.0 mM AA retained 98.2% of its initial

capacity, demonstrating excellent electrochemical stability of

This work was supported by the Research Foundation of Hanseo

University in 2020. The authors are grateful to the staﬀ of the

University for nancial support.

the electrode. As shown in Table 1, In

2

O

3

-G-SiO

2

-

References

nanocomposites had a high surface area and pore size, and

their sensing activity to glucose and AA was high due to these

properties. In addition, the stability and reproducibility of the

sensor were high, and it indicates that the eld of application of

this material is wide.

1

2

3

W. Animaw and Y. Seyoum, Increasing prevalence of

diabetes mellitus in a developing country and its related

factors, PLoS One, 2017, 12, e0187670.

C. Radhakumary and K. Sreenivasan, Naked eye detection of

glucose in urine using glucose oxidase immobilized gold

nanoparticles, Anal. Chem., 2011, 83, 2829–2833.

M. S. Kim and D.-Y. Lee, Urinary glucose screening for early

detection of asymptomatic type 2 diabetes in Jeonbuk

Province Korean schoolchildren, J. Korean Med. Sci., 2017,

32, 985–991.

3.6. Catalytic performance and detection mechanism

According to Fig. 7–10, there were 3 oxidation potentials located

at 0.18, 0.42, and 0.88 V corresponding to non-enzymatic

glucose and ascorbic acid detection in urine. The feasible

component of In O –G–SiO depended on the electrooxidation

2

3

2

4 N. Friedrich, T. Skaaby, M. Pietzner, K. Budde,

B. H. Thuesen, M. Nauck and A. Linneberg, Identication

of urine metabolites associated with 5-year changes in

biomarkers of glucose homoeostasis, Diabetes Metab., 2018,

44, 261–268.

5 P. Si, Y. Huang, T. Wang and J. Ma, Nanomaterials for

electrochemical non-enzymatic glucose biosensors, RSC

Adv., 2013, 3, 3487–3502.

6 K. Tian, M. Prestgard and A. Tiwari, A review of recent

advances in nonenzymatic glucose sensors, Mater. Sci.

Eng., C, 2014, 41, 100–118.

7 D. Pletcher, Electrocatalysis: present and future, J. Appl.

Electrochem., 1984, 14, 403–415.

of pre-monolayer hydroxyl Co active sites and oxide arrange-

ment of In O . The synergistic signicance of the OH-ads layer

2

3

was observed to mediate oxidation, followed by chemisorption

30

of glucose. These peaks were attributed to the reduction/

2

+

3+

oxidation of In /In and redox couples. Then, the glucose

oxidation kinetics of InOOH was studied along with the charge/

discharge proles of other important species, indicating the

decrease of oxygen release in glucose alternatives at a high

8

potential above 0.8 V. In neutral pH urine, In O could poorly

2

3

bond to the hydroxyl ions. Our results demonstrated the pres-

2

+

3+

ence of In /In redox couples. Hence, our proposed detection

system of In –G–SiO is summarized in eqn (2) and (3).

2

O

3

2

4268 | RSC Adv., 2021, 11, 4256–4269

View Article Online

Paper

RSC Advances

8

9

K. E. Toghill and R. G. Compton, Electrochemical non- 19 N. F. Zubair, S. Jamil, H. N. Bhatti and M. Shahid, A

enzymatic glucose sensors:

a

perspective and an

comprehensive thermodynamic and kinetic study of

evaluation, Int. J. Electrochem. Sci., 2010, 2010, 1246–1301.

synthesized rGO–ZrO composite as a photocatalyst and its

2

S. Fu, G. Fan, L. Yang and F. Li, Non-enzymatic glucose

use as fuel additive, J. Mol. Struct., 2019, 1198, 126869.

sensor based on Au nanoparticles decorated ternary Ni–Al 20 M. Rahsepar, F. Foroughi and H. Kim, A new enzyme-free

layered double hydroxide/single-walled carbon nanotubes/

graphene nanocomposite, Electrochim. Acta, 2015, 152,

biosensor based on nitrogendoped graphene with high

sensing performance for electrochemical detection of

glucose at biological pH value, Sens. Actuators, B, 2019,

282, 322–330.

146–154.

1

0 L. T. Hoa, K. G. Sun and S. H. Hur, highly sensitive non-

enzymatic glucose sensor based on Pt nanoparticle 21 N. Venkatathri, Synthesis of silica nanosphere from

decorated graphene oxide hydrogel, Sens. Actuators, B,

015, 210, 618–623.

homogeneous and heterogeneous systems, Bull. Mater. Sci.,

2007, 30, 615–617.

2

1 G.-h. Wu, X.-h. Song, Y.-F. Wu, X.-m. Chen, F. Luo and 22 L. Wang, J. Zhao, H. Liu and J. Huang, Design modication

X. Chen, Non-enzymatic electrochemical glucose sensor

based on platinum nanoowers supported on graphene

oxide, Talanta, 2013, 105, 379–385.

2 L. Hou, H. Zhao, S. Bi, Y. Xu and Y. Lu, Ultrasensitive and

highly selective sandpapersupported copper framework for

and application of semiconductor photocatalysts, J. Taiwan

Inst. Chem. Eng., 2018, 590–602.

23 B. M. Mohammed, B. J. Fisher, D. Kraskauskas, S. Ward,

J. S. Wayne, D. F. Brophy, A. A. Fowler, D. R. Yager and

R. Natarajan, Int. Wound J., 2015, 1–13.

non-enzymatic glucose sensor, Electrochim. Acta, 2017, 248, 24 M. Levavasseur, C. Becquart, E. Pape, M. Pigeyre,

2

81–291.

J. Rousseaux, D. Staumont-Sall ´e and E. Delaporte, Eur. J.

Clin. Nutr., 2015, 69, 1076–1077.

3 X. Liu, W. Yang, L. Chen and J. Jia, Three-dimensional

copper foam supported CuO nanowire arrays: an eﬃcient 25 S. Sasazuki, S. Sasaki, Y. Tsubono, S. Okubo, M. Hayashi and

non-enzymatic glucose sensor, Electrochim. Acta, 2017, 235,

19–526.

4 Y. Zhong, T. Shi, Z. Liu, S. Cheng, Y. Huang, X. Tao, G. Liao

S. Tsugane, Eur. J. Clin. Nutr., 2006, 60, 9–17.

26 N. Attallah, Y. Osman-Malik, S. Frinak and A. Besarab, Am. J.

Kidney Dis., 2006, 47, 644–654.

5

and Z. Tang, Ultrasensitive non-enzymatic glucose sensors 27 Y. Song, C. Gong, D. Su, Y. Shen, Y. Song and L. Wang, A

based on diﬀerent copper oxide nanostructures by in situ

growth, Sens. Actuators, B, 2016, 236, 326–333.

5 Q. Wang, Q. Wang, M. Li, S. Szunerits and R. Boukherroub,

novel ascorbic acid electrochemical sensor based on

spherical MOF-5 arrayed on a three-dimensional porous

carbon electrode, Anal. Methods, 2016, 8(10), 2290–2296.

Preparation of reduced graphene oxide/Cu nanoparticle 28 K. N. Fatema, S. Sagadevan, Y. Liu, K. Y. Cho, C. H. Jung and

composites through electrophoretic deposition: application

2 2 3

W. C. Oh, New design of mesoporous SiO combined In O -

for nonenzymatic glucose sensing, RSC Adv., 2015, 5,

graphene semiconductor nanocomposite for highly eﬀective

and selective gas detection, J. Mater. Sci., 2020, 55(27),

13085–13101.

15861–15869.

1

6 B. Hai and Y. Zou, Carbon cloth supported NiAl-layered

double hydroxides for exible application and highly 29 K. N. Fatema, M. R. U. D. Biswas, S. H. Bang, K. Y. Cho and

sensitive electrochemical sensors, Sens. Actuators, B, 2015, W. C. Oh, Electroanalytical characteristic of a novel

08, 143–150. biosensor designed with graphene–polymer-based

2

7 X. Li, J. Liu, X. Ji, J. Jiang, R. Ding, Y. Hu, A. Hu and X. Huang,

quaternary and mesoporous nanomaterials, Bull. Mater.

Sci., 2020, 43, 121.

Ni/Al layered double hydroxide nanosheet lm grown

directly on Ti substrate and its application for 30 M. Janyasupab, C. W. Liu, N. Chanlek, S. Chio-Srichan,

a nonenzymatic glucose sensor, Sens. Actuators, B, 2010,

47, 241–247.

8 Y. Shu, Y. Yan, J. Chen, Q. Xu, H. Pang and X. Hu, Ni and NiO

nanoparticles decorated metal–organic framework

nanosheets: facile synthesis and high-performance

nonenzymatic glucose detection in human serum, ACS

Appl. Mater. Interfaces, 2017, 9, 22342–22349.

C. Promptmas and W. Surareungchai, A comparative study

of non-enzymatic glucose detection in articial human

urine and human urine specimens by using mesoporous

bimetallic cobalt-iron supported N-doped graphene

biosensor based on diﬀerential pulse voltammetry, Sens.

Actuators, B, 2019, 286, 550–563.

1

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Article Doi

A comparative electrochemical study of non-enzymatic glucose, ascorbic acid, and albumin detection by using a ternary mesoporous metal oxide (ZrO2, SiO2and In2O3) modified graphene composite based biosensor

DOI: 10.1039/d0ra09886h

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Authors:

Article abstract of DOI:10.1039/d0ra09886h

Full text of DOI:10.1039/d0ra09886h

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