One-step facile synthesis of SnO2@Nd2O3 nanocomposites for selective amidol detection in aqueous phase

Article abstract of DOI:10.1039/d0nj00421a

In this approach, amidol, a toxic organic chemical, is used as a staining developer electrochemically detected by using binary SnO₂@Nd₂O₃ nanocomposites (NCs) by deposition onto a flat glassy carbon electrode (GCE). The NCs were prepared by a wet-chemical process followed by characterization with various conventional techniques, such as the UV-Vis, FTIR, XRD, FESEM, EDS and XPS techniques. During the electrochemical method, the main key points are the sensor analytical parameters, such as selectivity, sensitivity, linearity, concentration variations, validity, response time, and repeatability. The calibration curve was plotted in the full concentration range (FCR) from 0.1 mM to 0.1 nM. From the FCR, the linear dynamic range (LDR) was found in the range 1.0 mM to 0.1 nM. The sensitivity is calculated from the slope of the calibration plot in LDR, which was 158.228 μA μM^-1 cm^-2. The limit of detection (LOD) and limit of quantification (LOQ) of the fabricated chemical sensor were 0.06 nM and 0.2 nM. respectively. The binary doped NC-based chemical sensor probe is cheap, efficient, and environmentally friendly for detecting unsafe chemicals in the environmental and healthcare fields on a broad scale.

Full text of DOI:10.1039/d0nj00421a

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One-step facile synthesis of SnO2@Nd2O3 nanocomposites for selective amidol
detection in aqueous phase
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Mohammed M. Rahmana,b,*, Abdul Wahida,b, Abdullah M. Asiria,b, Md. Rabiul Awualb,
Mohammad R. Karima,b,c,
*
aChemistry department, King Abdulaziz University, Faculty of Science, Jeddah 21589, P.O. Box
80203, Saudi Arabia.
bCenter of Excellence for Advanced Materials Research, King Abdulaziz University, Jeddah
21589, P.O. Box 80203, Saudi Arabia.
cDepartment of Chemistry, Shahjalal University of Science and Technology, Sylhet 1100,
Bangladesh
*Corresponding address:
M.R. Karim ( mrkarimku@gmail.com )
M.M. Rahman ( mmrahman@kau.edu.sa )
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Abstract
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In this approach, Amidol is toxic oraganic chemical worked as a staining developer
which was electrochemically detected by using binary SnO2@Nd2O3 nanocomposites (NCs) by
depositing onto flat glassy carbon electrode (GCE). The NCs were prepared by wet-chemical
process followed by the characterization with various conventional techniques such as UV-Vis,
FTIR, XRD, FESEM, EDS and XPS techniques. During the electrochemical method, the main
key points are the sensor analytical parameteris, such as selectivity, sensitivity, linearity,
concentration variations, validity, response time, and repeatability. The callibration cuve was
plotted in full concentration range (FCR) ranging from 0.1 mM-0.1 nM. From the FCR, the
linear dynamic range (LDR) was found in 1.0 mM - 0.1 nM. The sensitivity is calculated from
the slope of the calibration plot in LDR, which was 158.228 µA.µM-1.cm-2. The limit of
detection (LOD) and limit of quantification (LOQ) of the fabricated chemical sesnor were 0.06
nM and 0.2 nM respectively. The binary doped NCs based chemical sensor probe was cheap,
efficient, and environmental friendly for detecting the unsafe chemicals in environmental and
healthcare fields in broad scales.
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Key words: SnO2@Nd2O3 nanocomposites; Amidol detection; Optical property; Electrochemical
method; Environmental safety
Introduction
Today, we have perfected our lifestyle with the latest technological tools to promote it.
But this rapid improvement negatively affects our environment as well as human health. So,
nowadays, in the last technological life, the protection of the environment is the main challenge
for scientists. Before inventing something new in life, it is more important to ask if it is safe for
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our environment. There are many residues from almost all types of industries that favor one type
or another of pollution, namely air, water or even noise. These substances that promote pollution
are called toxins or environmental pollutants. The main problem is to detect and eliminate these
toxic substances from the environment and the environment to make life healthier. These toxic
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substances in the environment can be detected by nanostructured oxide semiconductors using
advanced techniques. Being mesoporous 2, the nanostructures have a high dynamic surface area,
good permeability and are considered sensitive and effective against contaminants. Several
techniques used to eliminate toxins from environmental samples are ion exchange, reverse
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osmosis, ultrafiltration, photodegradation . These techniques are expensive and require a well-
defined laboratory to be performed. The adsorption technique with the use of friendly
nanocomposites (NC) is considered economical, effective and reusable due to its mesoporous
characteristics. The study of these industrial effluents is of utmost importance for the
management of the environment and safety, since it improves the standard of living of living
organisms. Among these chemical toxins, one of the most important is 2,4-diaminophenol or
simply amidol, which has the molecular formula C6H3(NH2)2OH. It is used as a developing agent
due to its satining persistency. A research has shown that amidol induced renal toxicity in rats.
Skin irriatation and severe ocular irritation was also examined when instilled into the eyes of
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albino rabbits . In addition using it as dye may create water toxicity after washing hair. The
toxic water resulted from amidol toxicity may cause damage to sculptures, construction as well
as civil sites. To avoid further negative impacts, it is good to detect it by an appropriate scientific
method. Gas chromatography technique is avoided due to high polarity and large molecular
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weight . The electrochemical method is considered a useful technique due to its low cost,
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responsiveness, simple orientation and sensitivity . In addition, this method is compatible
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because only the reagent degrades to the respective component without generating a contaminant
7. In this SnO2@Nd2O3 nanocomposite materials have employed a great deal of consideration
due to their chemical, structural, physical, and optical properties in terms of large-active surface
area, high-stability, high porosity, and permeability, which directly dependent on the structural
morphology prepared by reactant precursors for making binary doped materials in basic medium
at low-temperature 8-11. Here, the SnO2@Nd2O3 nanocomposite materials were synthesized by a
wet-chemical method using NaOH reducing agents at ambient conditions. This technique has
several advantages including facile preparation, accurate control of the reactant temperature,
easy to handle, one-step reaction, and high-surface area. Optical, morphological, electrical, and
chemical properties of SnO2@Nd2O3 nanocomposite materials are of huge significance from the
scientific aspect, compared to other doped or undoped materials 12-16. Non-stoichiometry, mostly
oxygen vacancies, makes it conducting nature in the doped nanocomposite materials. The
formation energy of oxygen vacancies and metal interstitials in semiconductor is very low and
thus these defects form eagerly, resulting in the experimentally elevated conductivity of
SnO2@Nd2O3 nanocomposite materials compared to other undoped 17-19. SnO2@Nd2O3
nanocomposite materials have also attracted considerable interest due to their potential
applications in fabricating opto-electronics, electro-analytical, selective detection of assays,
sensor devices, hybrid-composites, electron-field emission sources for emission exhibits,
biochemical detections, and surface-enhanced Raman properties etc 20-24. SnO2@Nd2O3
nanocomposite material offers improved performance due to the large-active surface area which
increased of conductivity and current responses of SnO2@Nd2O3 NCs/Nafion/GCE assembly
during electrochemical investigation. Finally, SnO2@Nd2O3 nanocomposites were prepared by
facile wet chemical process in alkaline medium, which is a promising component in a wide range
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of transition-doped semiconductor binary nanocomposite materials due to their novel
characteristics and attractive optical, morphological 25-27, structural and chemical properties. The
analytical performances of amidol sensor with large-active surface area of SnO2@Nd2O3 NCs
deposited GCE have higher sensitivity, lower detection limit, and long-term stability by reliable
electrochemical method.
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We used to develop the chemical sensor based on GCE decorated with SnO2@Nd2O3
NCs by electrochemical method at room conditions. The prepared binary doped NCs were
synthesized by a simple wet-chemical process in basic NaOH medium at low temperature. It was
noted that SnO2@Nd2O3/Nafion/GCE was unique and that it was possible to detect the selective
amidol with a short reaction time by electrochemical approach.
Experimental section
Materials and methods
During the process, the chemical that were utilized are tin (II) chloride dihydrate
(SnCl2.4H2O), neodymium chloride hexahydrate (NdCl3.6H2O), thiourea (CH4H2S), sodium
hydroxide (NaOH), monosodium phosphate (NaH2PO4), disodium phosphate (Na2HPO4), nafion
(C7HF13O5S·C2F4), and ethanol (C2H5OH). All these analytical grade chemicals were bought
from sigma Aldrich. The dried mass of SnO2@Nd2O3 NCs powder obtained during process were
diagnosed by UV-Vis spectroscopy (Lamda-950, PerkinElmer, Germany). FTIR spectra was
collected with spectrometer labelled (iS50 ATR Spectrum-100 FTIR) obtained from
PerkinElmer, Germany. The X-ray photon spectroscopy (XPS) spectra of SnO2@Nd2O3 NCs
was recorded by scientific K-alpha KA1066 spectrometer. The X-ray diffraction (XRD) pattern
was obtained by X-ray diffractometer (XRD, X’Pert Explorer, PANalytical diffractometer)
prepared with Cu Kα1 radiation (λ=1.5406nm) using generator voltage of 40kV and current of
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35mA. The morphological surface of SnO2@Nd2O3 NCs were diagnosed by FE-SEM instrument
(FESEM, JSM-7600F, Japan). The individual percentage of NCs components were carried out
using EDS from JEOL, Japan. An electrometer (Keithley, 6517A, Electrometer, USA) was used
based on current-voltage (I-V) technique during application. All of the working electrodes were
synthesized in the laboratory and the counter electrode was purchased from a particular
company. The electric current was measured against the applied voltage when both of the
electrodes were directly connected to electrometer for dioxane detection.
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Preparation of SnO2@Nd2O3 NCs
The wet chemical process is used to prepare the desired nanocomposites. During this
process, 50.0 mL of SnCl2.2H2O and 50.0 mL of NdCl3.6H2O were mixed in a beaker. Both
solutions have a molar strength of 0.1 M. After that, 100 mL were taken from a 0.2M thiourea
solution that acted as a surfactant. The mixture of these solutions was kept in a hot plate at a
temperature of 80 ° C for 3 hours with continuous agitation. During the heating process, a 2.0 M
NaOH base was added dropwise until a pH of 10 was acquired. The solution was cooled to room
temperature and the precipitate was kept separate to sediment. The excess water was poured
from the beaker and the precipitate was further washed with water and ethanol and allowed to
settle again. The mixture of ethanol and water was removed with a dropper and, for 3 days. The
precipitate was allowed to dry in an electric oven at a temperature of 80 ° C. The dry mass
obtained was milled using a traditional mortar and pestle. The fine powder nanocomposites
obtained after milling were calcined in a furnace at a temperature of 600 °C for a duration of 6
hours.
The possible chemical reactions (i-v) that occur during a wet chemical process are described
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NaOH(s)  Na+(aq) + OH-(aq)
(i)
(ii)
(iii)
(iv)
(v)
NdCl3.6H2O (s)  Nd3+(aq) + 3Cl-(aq) + 6H2O(l)
SnCl2.2H2O (s)  Sn2+(aq) + Cl-(aq) + 2H2O(l)
OH-(aq) + Nd3+(aq) + Ni2+( (aq)  Sn(OH)2(aq) ↓ + Nd(OH)3(aq)
Sn(OH)2 + Nd(OH)3(aq)  SnO2@Nd2O3 (s) ↓ + H2O(l)
↓
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Fabrication of SnO2@ Nd2O3/Nafion/GCE
The GCE surface was washed with ethanol and distilled water and dried. The NCs were
taken in watch glass and their suspension was carried out by addition of ethanol. The NCs slurry
was coated on the surface of GCE with a spatula and held aside to dry for 30 minutes. After that,
5% nafion was added using a dropper to bring the adhesion of NCs to the surface of the GCE.
The electrode was held on one side again to dry for a further 30 minutes. At this time, the
prepared electrode with NCs is called fabricated GCE and can be written as
SnO2@Nd2O3/Nafion/GCE. Full fabrication pathway is shown in the following Scheme 1.
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Scheme 1: Fabrication of GCE. (a-b) Preparation of GCE with ethanolic NCs slurry, (c) NCs
deposited onto bare GCE, (d) Dropping 5% nafion onto SnO2@Nd2O3/GCE, (e) Dried fabricated
SnO2@Nd2O3/Nafion/GCE sensor probe
Results and discussions:
Optical and structural characterization of NCs
Optically and structurally SnO2@Nd2O3 NCs were characterized by UV-Vis, FTIR, and
XRD techniques. As for UV-Vis spectroscopy is concerned, the wavelength calculated by the
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spectrometer was 236 nm
and diplayed in the Fig. 1(a). The band gap energy (Eg) was
calculated using Tauc’s rule. Graph was plotted for energy (hν) against (αhν)2. Where “α” is
absorption coefficeint. “h” is planck’s constant, and “ν” is frequency. According to the data
obained from UV-Vis, the calculated band gap energy was 3.55 eV 30 and is shown is in the Fig.
1(b). A comparative analyses of individual spectrum such as only SnO2, Nd2O3 and
SnO2@Nd2O3 NCs is measured and presented in ESM (; Fig. S1)
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FTIR results are displayed in the Fig. 1(c). As shown in the figure, the peaks as 3567 cm-
1, 3588 cm-1, 3620 cm-1, 3629 cm-1, 3649 cm-1, 3670 cm-1, 3690 cm-1, 3710 cm-1, 3736 cm-1,
3750 cm-1, 3820 cm-1, 3840 cm-1, 3854 cm-1, and 3870 cm-1 is due to alcohlic -OH stretch from
water. Isothiocyanate (N=C=S) strectch occurred at 2030 cm-1 and 2052 cm-1 which may be
possible due to thiourea used during synthesis. C=O stretch is shown by the peaks at 1055 cm-1,
1110 cm-1, 1637 cm-1, 1653 cm-1, 1685 cm-1, 1718 cm-1, and 1792 cm-1. Peaks at 1508 cm-1 and
1540 cm-1 is due to imine (N-O) stretch. Alcohlic -OH bending occurred at 1340 cm-1 and 1418
cm-1. One peak also obtained at 792 cm-1 which is due to C-H bending. Peak at 518 cm-1 is due to
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Sn-O stretching . Additionally, a comparative analyses of individual FTIR spectrum for only
SnO2 as well as Nd2O3 and SnO2@Nd2O3 NCs is measured and presented in ESM (β; Fig. S2)
Crystalline structure of prepared SnO2@Nd2O3 NPs were observed using XRD patterns.
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Peaks for tetragonal SnO2 was assigned using JCPDS Card No. 41-1445 . The main peaks for
the tetragonal SnO2 at 26, 35 and 51 corresponded to the (110), (101) and (211) planes,
respectively. Peaks for hexagonal Nd2O3 were assigned using JCPDS Card NO. 41-1089 33. The
main peaks for the hexagonal Nd2O3 obtained at 30, 41, 46, 55, 58, 65, 74 and 78 corresponded
to the (002), (102), (110), (103), (201), (202), (203) and (211) planes respectively. Here,
comparative analyses of individual powder XRD spectrum for only SnO2 as well as Nd2O3 and
SnO2@Nd2O3 NCs is measured and given in ESM (; Fig. S3)
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Figure 1: Optical and Structural analysis of NCs. (a) UV-Vis plot of SnO2@Nd2O3 NCs, (b)
Tauc’s plot for band gap SnO2@Nd2O3 NCs (c) FTIR plot of calcined and non-calcined
SnO2@Nd2O3 NCs, (d) XRD spectra of calcined and non-calcined SnO2@Nd2O3 NCs
Morphology and elemental analyses of NCs
Here, SEM technique was used for surface analysis as well size of the SnO2@Nd2O3
NPs. Low and highly magnified SEM images are shown in the Fig. 2(a-b). The average size of
the NPs calculated were 155.47 nm with a minumum value of 130.08 nm and maximum value of
177.77 nm. A comparative morphological analyses of individual surface images for only SnO2 as
well as Nd2O3 and SnO2@Nd2O3 NCs is measured and given in ESM (; Fig. S4). Selected area
of SEM image is measured for EDS (elemental compositions) and is shown in the Fig. 2(c). Fig.
3(d) shows the weight and atomic percentages of oxygen, tin, and neodymium. According to the
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EDS spectrum, the atomic mass percentages of oxygen, tin, and neodymium are 37.70%, 2.60% ,
and 59.70% respectively.
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Figure 2: Morphological and Elemental analysis of NCs. (a)-(b) Zoomed-out and zoomed-in
SEM images of calcined SnO2@Nd2O3 NCs (c) Section from SEM image for EDS, (d) EDS
spectra of calcined SnO2@Nd2O3 NCs with inset showing weight and atomic percentages
BET analysis:
In this approach, the N2 adsorption-desorption isotherms were carried out by the 3Flex
analyzer (Micromeritics, USA) at 77 K. The specific surface area (SBET) was calculated using
multi-point adsorption data from the linear segment of the N2 adsorption isotherms using BET
theory. The surface characterization of the SnO2@Nd2O3 NCs based on the N2 adsorption-
desorption isotherms showed the IV-type isotherm with hysteresis loop, which was
representative of the mesoporous ordered framework textural pores as judged from bellow Fig. 3.
In addition, the mesoporous SnO2@Nd2O3 NCs exhibited significant high surface area (SBET),
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pore volume, and pore diameters according to the data analysis. Also the N2 isotherm indicated
the uniform channels with well pore size having surface area of 7.26 m2/g, and high pore volume
of 0.021 cm3/g and pore diameter of 2.43 nm. The high surface area of the mesoporous
SnO2@Nd2O3 NCs exhibited case cavities from reduction of reactant precursors using alkaline
medium.
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Fig. 3. Analysis of BET for SnO2@Nd2O3 nanocomposites
XPS analysis
Fig. 4(a) shows the XPS spectra of calcined SnO2@Nd2O3 NPs prepared by wet chemical
process. Individual elemental areas are encircled in for tin, oxgyen, and neodymium. As of
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binding enegies are concerned two peaks for Nd(3d) present between 980 eV-1005 eV and is
shown in the Fig. 4(b). Nd 3d5/2 and Nd 3d3/2 levels are associated to 985.2 eV 34 and 1004 eV 35
respectively. Fig. 4(c) shows the peaks for tin which are associated between 480 eV-496 eV. The
XPS peaks for Sn(3d) are present at 484.2 eV and 495.1 eV which asssigned to Sn 3d5/2 and Sn
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3d3/2 energy levels respectively . One XPS peak of oxygen is shown in Fig. 4(d). The peak
present at 531.29 eV is associated with O 1s level 37.
Figure 4: XPS analysis of NCs. (a) XPS spectrum of calcined SnO2@Nd2O3 NCs, (b) XPS
spectrum of Neodymium, (c) XPS spectrum of Tin, and (d) XPS spectrum of Oxygen
Electrochemical detection of amidol by SnO2@Nd2O3/Nafion/GCE sensor probe
The fabricated sensor was prepared with different chemicals to find out where the sensor
is more selective towards a particular analyte using the sensor probe assembly as
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SnO2@Nd2O3/Nafion/GCE electrode. Fig. 5(a) shows the selectivity results for the prepared
chemical sensors toward different chemicals (2,4-diaminophenol, 2-nitrophenol, 3-chlorophenol,
3-methoxyphenyl hydrazine, 4-hexylresorcinol, 4-nitrophenyl hydrazine, hydrazine, m-tolyl
hydrazine, and melamine) in the phosohate buffer solution (PBS) system. According to the
results shown, amidol is more sensitive toward the chemical sensor as compared to the other
chemicals. Amidol was tried in different pH solutions (from 5.7 to 8.0) of PBS systems. Fig. 5(b)
shows that pH 5.7 show better results as compared to other PBS strengths. The experiment was
also tried in controlled conditons using bare and coated GCE. Fig. 5(c) shows that the coated
GCE is more responsive as compared to bare one.
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Figure 5: Control experiments. (a) Seletivity stuy in various chemicals (Amidol, 2-
nitrophenol, 3-chlorophenol, 3-methoxyphenyl hydrazine, 4-hexylresorcinol, 4-nitrophenyl
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hydrazine, hydrazine, m-tolyl hydrazine, and melamine) with SnO2@Nd2O3/Nafion/GCE sensor
probe by electrochemical method, (b) pH variations with SnO2@Nd2O3/Nafion/GCE in different
pH (5.7 to 8.0), and (c) Electrochemical responses of bare and SnO2@Nd2O3 coated GCE
electrode for the detection of amidol by electrochemical method.
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Different concentration strengths of amidol were checked ranging from 0.1 M – 0.1 nM. Fig. 6a
shows from higher to lower concentrations range. The inset in Fig. 6a shows current change
stated at 1.0 V. In order to check the reproducibility of the results by the
SnO2@Nd2O3/Nafion/GCE chemical sensor, the amidol was detected repeatedly in PBS system.
The repeatabilty results are shown in the Fig. 6b. The calibration curve was plotted full
concentraton ranging from 0.1 M – 0.1 nM and is displayed in the Fig. 6c. There is prominent
change in the current (Fig. 6a) at 1.1 V, the calibraton curve was plotted as this potential. The
linear dynamic range (LDR) according to plotted curve was 1.0 mM - 0.1 nM. It is also
compared the electrochemical performance with undoped SnO2 and Nd2O3 with doped binary
SnO2@Nd2O3 NCs materials by electrochemical method, which is presented in Fig. 6d. From
this observation, it is found that the highest electrochemical response was observed with binary
doped SnO2@Nd2O3/Nafion/GCE sensor probe compared to undoped sinlge oxides SnO2 and
Nd2O3.
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Figure 6: Detection of amidol chemical with SnO2@Nd2O3/Nafion/GCE. (a) Concentration
variations of SnO2@Nd2O3/Nafion/GCE to amidol with inset show distinct cahnge, (b)
Repeatability tests of SnO2@Nd2O3/Nafion/GCE, (c) Calibration curve with inset showing LDR,
and (d) Comparative electrochemical response with only Nd2O3/Nafion/GCE, only
SnO2/Nafion/GCE and SnO2@Nd2O3/Nafion/GCE.
Here, amidol is converted into aminohydroquinone, which has been reported in the literature by
Salavagione et al. 38. There are also some intermediates formed during various chemical reaction
occured. During electrolysis of amidol with SnO2@Nd2O3/Nafion/GCE, it is oxidized into 2-
amino-1,4-benzoquinone imine, which is reported by Vasilikiotis et al 39. Further amidol is
converted into aminoquinone and aminohydroquinone, which is took place during the
electrochemical process. This phenomena is described by Salavagione et al in their previous
40
report elsewhere
.
The whole mechanism of the reaction is described with
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SnO2@Nd2O3/Nafion/GCE during electrochemical process to detect the amidol and presented in
the Scheme 2.
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Scheme 2: Detection mechanism of amidol with SnO2@Nd2O3 NCs sensor probe. (a)
Fabrication of SnO2@Nd2O3/Nafion/GCE sensor probe with nafion binders with GCE, (b)
Amidol conversion scheme onto SnO2@Nd2O3/Nafion/GCE surface, (c) Theoritical
electrochemical results, (d) Practical electrochemical results
In this approach, the higher sensitivity of the coated-film of SnO2@Nd2O3/Nafion/GCE
can be attributed to the good absorption of analyte in porous surface, good adsorption capability,
high catalytic activity, and biocompatibility 41, 42. The fabricated sensor is eco-friendly due to
large surface area and is favorable to detect target analyte in good quantity 28, 43, 44. These
chemical sensors are beneficial because it provides direct electron transfer between
SnO2@Nd2O3/GCE and GCE surface. As for binary doped nanomaterial is concerned,
SnO2@Nd2O3/Nafion/GCE based sensors provide a new pathway for the detection of amidol in
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large quantity and can give favorable results. Furthermore, efforts are demanded for research
development in the field of chemical sensors to achieve large scale applications to acquire more
selective and sensitive sensors 45.
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Real sample analyses
The amount of amidol present in the real extracted samples were also determined with the
SnO2@Nd2O3/Nafion/GCE sensor probe by electrochemical method. The extracted samples that
selected for the sampling were industrial water (IW), polycarbonate bottle-safa (PCB-SAFA),
polycarbonate-baby bottle (PC-BB), and polyvinylchloride-food package bag (PVC-FPB) in the
PBS system. It was found the acceptable results, which is given below in the Table 1.
Table 1: Detection of amidol in different extracted samples by electrochemical method with
SnO2@Nd2O3/Nafion/GCE sensor probe
Real samples
Conc. ranges
Measured current
(µA)
Respective conc.
(nM)
IW
1.0 pM – 1.0 mM
1.0 pM – 1.0 mM
1.0 pM – 1.0 mM
10.06
2.72
0.074
PCB SAFA
PC BB
0.020
0.189
0.153
25.62
PVC FPB
1.0 pM – 1.0 mM
20.75
Conclusions
In this approach, we have successfully prepared an amidol sensor based on SnO2@Nd2O3
NCs/Nafion/GCE by electrochemical process, which was initially prepared using facile wet-
chemical method in alkaline medium. The fabricated sensor was used for the detection for
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amidol by using electrochemical method in room conditions. The sensitivity, LOD, and LOQ of
the fabricated sensor were calculated as 158.228 µA.µM-1.cm-2, 0.06 nM, and 0.2 nM
respectively. So the prepared SnO2@Nd2O3/Nafion/GCE sensor probe is very sensitive, cheap,
rerliable, linear, repeatibile, valid, and environment friendly in the detection processes in order to
reduce the problems which caused by amidol. It is introduced a well-known route to detect the
hazardous chemicals using doped nanomaterials by electrochemical method for the safety of
healthcare and environmental fields.
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Acknowledgement
We are thankful to Center of Excellence for Advanced Materials Research (CEAMR),
and Chemistry Department, King Abdulaziz University, Jeddah, Kingdom of Saudi Arabia for
financial supports and research facilities.
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