A novel fluorescent functional monomer as the recognition element in core-shell imprinted sensors responding to concentration of 2,4,6-trichlorophenol

Article abstract of DOI:10.1039/c7ra07742d

We have demonstrated a fluorescent functional monomer instead of the traditional functional monomers for molecularly imprinted sensors. The sensors were firstly used to selectively detect 2,4,6-trichlorophenol (2,4,6-TCP) by solid fluorescence detection without a dispersion solution. Moreover, the selectivity and anti-interference ability of the SiO₂@dye-FMIPs sensor meet the requirements of a fluorescent sensor. The novel fluorescent monomer introduced into MIP is no longer just a fluorophore without recognizing ability. The fluorescence intensity of SiO₂@dye-FMIPs showed a linear response to 2,4,6-TCP concentration in the range of 0-100 nM with a detection limit of 0.0534 nM. We could also demonstrate that such a system can not only get rid of the confines of traditional functional monomers and detection manner, but also improved the applications of MIPs sensors in sensing systems.

Full text of DOI:10.1039/c7ra07742d

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PAPER
A novel fluorescent functional monomer as the
recognition element in core–shell imprinted
sensors responding to concentration of 2,4,6-
trichlorophenol†
Cite this: RSC Adv., 2018, 8, 6083
*
*
Bo Hu,
Baixiang Ren, Huan Qi, Xiuying Li, Lihui Liu, Lin Gao,
Liang Wang and Xue Lin
Guangbo Che,
We have demonstrated a fluorescent functional monomer instead of the traditional functional monomers
for molecularly imprinted sensors. The sensors were firstly used to selectively detect 2,4,6-trichlorophenol
(2,4,6-TCP) by solid fluorescence detection without a dispersion solution. Moreover, the selectivity and
anti-interference ability of the SiO2@dye-FMIPs sensor meet the requirements of a fluorescent sensor.
The novel fluorescent monomer introduced into MIP is no longer just a fluorophore without recognizing
Received 14th July 2017
Accepted 23rd January 2018
ability. The fluorescence intensity of SiO2@dye-FMIPs showed
a linear response to 2,4,6-TCP
concentration in the range of 0–100 nM with a detection limit of 0.0534 nM. We could also
demonstrate that such a system can not only get rid of the confines of traditional functional monomers
and detection manner, but also improved the applications of MIPs sensors in sensing systems.
DOI: 10.1039/c7ra07742d
rsc.li/rsc-advances
The central part of a chemical sensor is the recognition
element in order to assess the binding events directly with
1 Introduction
a sensitive analytical procedure, for example uorescence
detection technique.10–15 Fluorescence detection based on uo-
rescent sensors is the most valuable method utilized in sensing
thanks to its high sensitivity and simplicity. Fluorescence
detection is the superior detection method in the eld of
sensing technology owing to several well-established advan-
tages. Such signaling MIPs would be a sensor material and
would expand the application of MIPs in uorometric analysis
instead of uorescence label and displacement assays.16–21 MIPs
are usually used to separate analytes as a selective sorbent. A
further analysis will then be carried out by other apparatus,
which is not ideal for sensor applications.
MIPs in which uorescent moieties are directly incorporated
in the polymer are scarce. Moreover, the covalently embedded
dye can only be employed as a uorophore without recognition
ability.22,23 Perhaps the most feasible method, the covalent
integration of a uorescent probe monomer into an MIP,
cannot however form the recognition sites with a functional
monomer like methacrylic acid.24–27 As the most appealing type,
if we can nd a uorescent functional monomer that catches an
analyte by hydrogen bonds, hydrophobic interactions, and/or
p–p stacking interactions, the application of MIPs as a uores-
cence sensor would provide satisfactory uorometric analysis.
To develop MIPs that show a reduction of uorescence upon
analyte binding and perform well in molecular recognition, we
chose 7-allyloxycoumarin as the uorescent functional mono-
mer. It is constructed from a coumarin uorophore and an
Molecularly imprinted polymers (MIPs) with functional groups
are an indispensable and powerful medium for selectively
enriching and separating chemical species, in particular for
small organic molecules. They are generally assembled by
polymerizing functionalized monomers interacting with
template molecules that are representative of the target or
a similar molecule in size and chemical functionality. Once the
templates are removed, cavities that are complimentary in
terms of appropriate size and chemical functional demand
remain in the cross-linked polymer matrix, compared to
molecular non-imprinted polymers (NIPs), prepared for selec-
tively recognizing and binding the target molecule.1–3 MIPs have
been used as chromatographic stationary phases or solid-phase
extraction materials for their numerous advantages, such as
excellent recognition properties, easy preparation, low cost,
durability to heat and pressure, storage stability and applica-
bility in harsh chemical media. Recently, MIPs have been
applied for rather advanced analytical tasks, such as chemical
sensing,4–9 but the key step for their future success in a broader
range of applications is introducing additional functional
features.
Key Laboratory of Preparation and Applications of Environmental Friendly Materials,
Jilin Normal University, Ministry of Education, Changchun, 130103, People's Republic
of China. E-mail: gaolinujs@163.com; guangboche@jlnu.edu.cn; Tel: +86
18843410256; +86 17704348899
† Electronic supplementary information (ESI) available. See DOI:
10.1039/c7ra07742d
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allyloxy moiety, which can recognize templates via hydrogen chloroform, and the resulting product was separated by column
bonds and p–p interactions. In addition, most uorogenic chromatography on silica to obtain the product as a white
1
MIPs are simply dispersed in solution at the presence of ana- powder. H NMR (400 MHz, CDCl3) d 7.63 (d, J ¼ 9.5 Hz, 1H),
lytes in an analytical process. So, the unsteady dispersion 7.37 (d, J ¼ 8.6 Hz, 1H), 6.92–6.77 (m, 2H), 6.25 (d, J ¼ 9.5 Hz,
solution may bring about an inaccurate result. Maybe solid 1H), 6.04 (ddt, J ¼ 17.2, 10.6, 5.3 Hz, 1H), 5.39 (ddq, J ¼ 36.3,
uorescence detection can solve the problem.
10.5, 1.4 Hz, 2H), 4.60 (dt, J ¼ 5.3, 1.5 Hz, 2H), in Fig. S1.†
2,4,6-Trichlorophenol (2,4,6-TCP), widely employed in the
manufacturing of fungicides, herbicides, pesticides, insecti- Preparation of SiO2 beads modied by MPS
cides, antiseptics, pharmaceuticals, dyes and plastics, has been
2 mL of ammonium hydroxide and 25 mL of double distilled
listed as a priority pollutant by the US Environmental Protection
Agency and the European Union,28 together with some other
chlorophenol congeners. Adverse effects on human health
caused by TCP, such as respiratory effects from coughs to
serious pulmonary defects, gastrointestinal effects, and
cardiovascular effects, have been reported.26 Even low levels of
2,4,6-TCP in drinking water may be a serious threat to human
health and natural ecosystems. Therefore, it is important to
monitor the concentration of 2,4,6-TCP for human health,
safety and environmental protection purposes.
In this work, we chose 2,4,6-TCP as our template, 7-allylox-
ycoumarin as the uorescent functional monomer, ethylene
glycol dimethacrylate (EGDMA) as the crosslinker, and 3-
(methacryloxyl)propyltrimethoxysilane (MPS)-modied SiO2
spheres as the solid carrier to prepare an ideal uorescent MIP
sensor SiO2@dye-MIPs.
water were added to 25 mL of ethanol and stirred for 15 min.
The mixture was poured into a 100 mL ask. Then, 2.0 mL of
TEOS was added into the ask sequentially and stirred at
300 rpm continuously at room temperature. Aer 6 hours, SiO2
spheres were separated by centrifuge and washed by ethanol
and double distilled water.
The SiO2 spheres were redispersed in 40 mL of ethanol
inside a round-bottomed ask and 1 mL of MPS was added into
the ask. The round-bottomed ask was submerged in a ther-
mostatically controlled oil bath at 40 ꢀC and stirred at 300 rpm
for 24 hours. The resulting SiO2–MPS spheres were separated by
centrifuge from the solvent and washed ve times sequentially
in ultrasonic baths containing ethanol. Finally, the SiO2–MPS
beads obtained were dried under vacuum for 12 hours at 40 ꢀC.
Preparation of SiO2@dye-FMIP and SiO2@dye-FNIP
SiO2@dye-FMIP and SiO2@dye-FNIP were prepared by surface
molecular imprinting technique (SMIT). 1.0 g of MPS-modied
SiO2 beads was added to a 100 mL round-bottomed ask and
dispersed in 60 mL of acetonitrile by sonication for 30 min.
Then, 2,4,6-TCP (0.394 g, 2.0 mmol), 7-allyloxycoumarin
(0.404 g, 2.0 mmol) and EGDMA (1.88 mL, 10.0 mmol) were
dissolved in the round-bottomed ask in a glove box with N2.
The reaction system was sparged with oxygen-free nitrogen for
15 min to expel the oxygen present inside the reaction ask. The
ask was then submerged in a thermostatically controlled oil
bath at 70 ꢀC. Aer 3 hours, the SiO2@dye-FMIPs particles were
collected from the reaction medium by centrifuge and then
cleaned successively with methanol/acetic acid (100 mL, 95/5 v/
v) to remove the templates by Soxhlet extractor. Finally, the
product was dried in vacuo overnight at 40 ꢀC. Fluorescent
SiO2@dye-NIPs were prepared under nominally duplicate
conditions to those used for the SiO2@dye-FMIPs in the
absence of the 2,4,6-TCP template. By gravimetric analysis, the
yields of SiO2@dye-FMIPs and SiO2@dye-FNIPs were found to
be 87% and 83%, respectively.
2 Experimental section
Materials and instruments
Tetraethyl orthosilicate (TEOS), 3-(methacryloxyl)propyl-
trimethoxysilane (MPS), 2,4-dichlorophenol (2,4-DCP), 2,5-
dichlorophenol (2,5-DCP), 2,6-dichlorophenol (2,6-DCP), 2,4,6-
trichlorophenol (TCP), N,N-dimethylformamide (DMF, 99.5%),
allyl bromide, 7-hydroxycoumarin, ethylene glycol dimethacry-
late (EGDMA), and 2,20-azobis(2-methylpropionitrile) (AIBN)
were obtained from Aladdin Reagent Co., Ltd. (Shanghai,
China). Allyl bromide, acetonitrile, acetone, methanol, acetic
acid and ammonia solution were all purchased from Sinopharm
Chemical Reagent Co., Ltd. (Shanghai, China). Double distilled
water was prepared in our laboratory and used for cleaning
processes. All other chemicals used were of analytical grade and
were obtained commercially.
1H-NMR spectroscopy was recorded on a Bruker AVANCE III
HD400 NMR spectrometer. The morphologies of the samples
were observed by an S-5500 scanning probe microscope and
a transmission electron microscope (TEM, JEM-2100). Fluores-
cence intensity was measured using an F-4600 FL
spectrophotometer.
The solid uorescence detection experiments
The samples of SiO2@dye-FMIPs (100.0 mg) were dispersed in
100.0 mL of alcohol solution for spectrum measurement. Aer
that, 2,4,6-TCP solutions in ethanol were prepared at various
Synthesis of 7-allyloxycoumarin
7-Allyloxycoumarin was prepared by Williamson reaction. A concentrations in the range of 0–1000 nmol. For the uorescent
mixture of 7-hydroxycoumarin (1.62 g, 10.0 mmol), allyl measurements, 5 mL of the sample solution was mixed with
bromide (2.42 g, 20.0 mmol), K2CO3 (4.97 g, 36.0 mmol) and 5 mL of the 2,4,6-TCP solutions of different concentrations.
acetone (60 mL) was heated and stirred at 57 ꢀC in the dark Aer 1.0 hour of dipping, the solids were separated by centri-
under N2 for 10 h. The solvent was evaporated under reduced fuge and dried in vacuo overnight at 40 ꢀC. Then a uorescence
pressure. The crude product was recrystallized from spectrophotometer was used to detect the uorescence intensity
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of the SiO2@dye-FMIPs sensors. Fluorescence spectra were 7-allyloxycoumarin in dichloromethane (in Fig. S2†). This blue
measured under a 332 nm excitation light source. The uores- shi in the absorption spectra might be attributed to the
cence quenching efficiency of the SiO2@dye-FMIPs sensors with hydrogen bond between 2,4,6-TCP and 7-allyloxycoumarin.
2,4,6-TCP was calculated by Stern–Volmer equation (I0/I) ꢁ 1 ¼ Versus covalent methods, non-covalent formation of MIPs is
K
SVC (I0 is the initial uorescence intensity without analyte, I is most oen employed for introducing functionality into MIPs
the uorescence intensity of the SiO2@dye-FMIPs with different because of easier methodology and faster elution as a conse-
standard 2,4,6-TCP concentrations, and KSV is the quenching quence of the rapid and reversible nature of the non-covalent
constant with 2,4,6-TCP).
interaction between the polymer and the template.
As an alternative to molecular imprinting technique, surface
molecular imprinting technique has emerged as an attractive,
simple, and seemingly general method for facilitating the
production process of imprinted products. The reason that we
chose SiO2 microspheres as the solid support is because they
possess a vast surface area, physical robustness and thermal
stability, and can also be integrated in MIPs membranes.29,30
Silica particles of about 255 nm were used as the support, as
measured from the SEM image (Fig. S3†). The pure SiO2@dye-
FMIPs was highly spherical and monodisperse with an
average size of about 275 nm, as shown in Fig. S4.† A repre-
sentative TEM image of the pure SiO2@dye-FMIPs is shown in
Fig. S5;† when MPS-modied SiO2 spheres were coupled with
the dye-FMIP layer, the grain size was increased by about 20 nm.
In order to make 7-allyloxycoumarin copolymerise with other
monomers in the MIP system, allyl groups were attached to the
Selectivity experiments
To estimate the selectivity of the SiO2@dye-FMIPs sensor, we
made
a comparison between three structurally related
compounds and 2,4,6-TCP. The 100 mg SiO2@dye-FMIP sensors
were added to 100 mL of ethanol solutions containing 20.0
nmol of 2,4,6-TCP, 2,4-TCP, 2,5-TCP or 2,6-TCP. The mixtures
were stirred for 1 hour at room temperature and solids were
separated by centrifuge. The uorescence intensity of the solids
was detected by uorescence spectrophotometer and the [(I0/I)
ꢁ 1] was calculated with the uorescence data. For comparison,
the same procedure was applied using SiO2@dye-FNIPs instead
of SiO2@dye-FMIPs.
Interference experiments
The capacity to resist interferents is one key fact to evaluate hydroxyl by reacting with allyl bromide. The structural proper-
whether a sensor would be used in practical samples. To eval- ties of the synthesised SiO2@dye-FMIPs microspheres were
uate the SiO2@dye-FMIPs sensor's capacity of resisting inter- analysed by FT-IR spectra. As shown in Fig. S6,† the character-
ferents, 100 mg of SiO2@dye-FMIP was added into 100 mL of istic peaks at 1730, 1258 and 1151 cmꢁ1 are attributed to the
ethanol solutions containing 20.0 nmol of 2,4,6-TCP, 2,4-TCP, stretching of the C]O and C–O of EGDMA. The typical peaks of
2,5-TCP or 2,6-TCP. Aer stirring for 1 hour at room tempera- 2986 and 2956 cmꢁ1 proved that 7-allyloxycoumarin had copo-
ture, solids were separated by centrifuge. The uorescence lymerised with other monomers in the MIP system. The strong
intensity of the solids was detected by uorescence and broad peak around 1103 cmꢁ1 indicated the Si–O–Si
spectrophotometer.
asymmetric stretching. These FT-IR spectra suggest that the
SiO2@dye-FMIPs have been successfully prepared.
The performances of the SiO2@dye-FMIPs and SiO2@dye-
FNIPs sensors were assessed by solid uorescence with 2,4,6-
TCP. Structural analogues 2,4-dichlorophenol (2,4-DCP), 2,5-
dichlorophenol (2,5-DCP), and 2,6-dichlorophenol (2,6-DCP)
were chosen as potential competitors. Solid uorescence
spectra were measured under a 332 nm excitation light source at
room temperature. To study the uorescence quenching
mechanism of SiO2@dye-FMIPs sensors with 2,4,6-TCP, the
quenching efficiency of SiO2@dye-FMIPs was evaluated by the
Stern–Volmer equation (I0/I) ꢁ 1 ¼ KSVC (I0 is the initial uo-
rescence intensity of SiO2@dye-FMIPs, I is the peak of the
SiO2@dye-MIPs with different standard 2,4,6-TCP, and KSV is
the quenching constant with 2,4,6-TCP).
3 Results and discussion
One of the factors that limits the application of uorescent
molecular imprinting is the complexity of the uorescent
functional monomer. Herein, we adopted the Williamson
reaction to synthesize 7-allyloxycoumarin, which greatly
simplied the process of the preparation of uorescent func-
tional monomers. As-synthesized 7-allyloxycoumarin not only
had a recognition group but could also polymerize with other
monomers (Scheme 1). To our knowledge, there are no reports
about 7-allyloxycoumarin being used for MIPs, probes or
sensors. The crucial interaction between 7-allyloxycoumarin
and 2,4,6-TCP is hydrogen bonding because the absorption
peak position of 2,4,6-TCP has a blue shi of 12 nm aer adding
Scheme 1 Schematic illustration of the synthesis of 7-allyloxycoumarin.
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As shown in Fig. 1, a signicant inverse relation was found Stern–Volmer quenching constant in units of L molꢁ1. C is the
between uorescence intensity and 2,4,6-TCP concentration. The concentration of the molecular target. Kq is the rate constant of
more 2,4,6-TCP that is added, the weaker the uorescence inten- the bimolecular quenching process in units of L molꢁ1 sꢁ1. s0 is
sity is. It means that the uorescence intensity of SiO2@dye-FMIPs the lifetime without quenching agent.
(Fig. 1a) decreases with increasing 2,4,6-TCP concentration, and
Time-resolved uorescence curves of SiO2@dye-FMIPs
the reduced degree of uorescent SiO2@dye-FMIPs was notably before and aer adsorbing 2,4,6-TCP are shown in Fig. 3. The
higher than that of the uorescent SiO2@dye-FNIPs (Fig. 1b). It is two decay curves were tted by exponential function. The
illustrated that the spatial adsorption sites could be incorporated nonlinear equations of SiO2@dye-FMIPs before and aer
into the SiO2@dye-FMIPs matrix, but not in SiO2@dye-FNIPs. adsorbing 2,4,6-TCP are I(t) ¼ 42 065.8 exp(ꢁt/4.01076) +
Therefore, it is also conrmed that SiO2@dye-FMIPs particles 0.00304 and I(t) ¼ 2.47042 ꢂ 1010 exp(ꢁt/1.79746) + 0.00363,
are more sensitive than SiO2@dye-FNIPs particles.
and the corresponding correlation coefficients (R2) were R2 ¼
The excellent linearity of the technique was investigated 0.98147 and R2 ¼ 0.98801, respectively. From the equations, we
though the relationship of the uorescence intensity with the found that the lifetimes were s0 ¼ 4.01076 ns and s ¼ 1.79746
concentration of 2,4,6-TCP in a working range from 0 to 100 nM, ns, respectively. The lifetimes were quite different in the pres-
as shown in Fig. 2. The linear equation of the SiO2@dye-FMIPs ence and absence of 2,4,6-TCP. We found another kind of
sensor was (I0/I) ꢁ 1 ¼ 0.01051Cc + 0.00582 (where Cc is the representation of the Stern–Volmer equation according to
concentration of 2,4,6-TCP in nM, and (I0/I) ꢁ 1 is the relative eqn (1):
uorescence intensity), and the corresponding correlation coeffi-
cient (R2) was 0.99947. The limit of detection was evaluated using
3s/S, and was found to be 0.0534 nM (s is the standard deviation of
the blank signal and S is the slope of the linear calibration plot).
From the gure, we can see that the linear concentration range of
SiO2@dye-FMIPs is much larger than that of SiO2@dye-FNIPs.
This is because the quenching only took place between 7-allylox-
ycoumarin and 2,4,6-TCP at the surface of the SiO2@dye-FNIPs
particles with no recognition sites, and did not happen both
inside and outside like with the SiO2@dye-FMIPs particles.
It is well known that uorescence quenching processes
includes dynamic quenching and static quenching. In
a dynamic quenching process, excited state molecules and
quencher molecules collide with each other, leading to transi-
tion of the excited state molecule back to the ground state. At
the same time, the lifetime of the uorescent material reduces
with the variety of uorescence intensity. Static quenching
happens between the quenching agent and the uorescent
molecule in the ground state, but the uorescence lifetime is
not changed. Both dynamic quenching and static quenching
processes can be described by the Stern–Volmer equation:
s0/s ¼ 1 + KSVC ¼ 1 + Kqs0C
(2)
where s is the lifetime with quenching agent.
According to eqn (2), we found the relationship KSV ¼ Kqs0.
KSV is 0.01051 L molꢁ1, as shown in Fig. 2. Therefore Kq is 2.6 ꢂ
106 L molꢁ1 sꢁ1. The rate constant (Kq) of maximum diffusion
controlled dynamic quenching is 2.0 ꢂ 1010. The Kq in here is
always <2.0 ꢂ 1010 L molꢁ1 sꢁ1. In addition, the lifetime of
uorescent sensors reduces with the variety of uorescence
intensity. Thus, it is conrmed that dynamic quenching is
a dominant process in this work.
Selectivity is a very important index for a sensor. To evaluate
the selective recognition property of the SiO2@dye-FMIPs
sensor, we chose structural analogues 2,4-DCP, 2,5-DCP, and
2,6-DCP as the competitors. Fig. 4 shows the uorescence
quenching efficiency of SiO2@dye-FMIPs for 2,4,6-TCP, 2,4-
DCP, 2,5-DCP and 2,6-DCP. The uorescence quenching effi-
ciencies (I0/I) ꢁ 1 are 0.249, 0.024, 0.011 and 0.02, respectively.
So, the uorescence quenching efficiency of 2,4,6-TCP is much
higher than other competitors. The results showed that none of
the competitors being evaluated led to signicant uorescence
quenching and the SiO2@dye-FMIPs sensor had a specic affi-
nitive action owing to its recognition sites. In order to evaluate
I0/I ¼ 1 + KSV[C] ¼ 1 + Kqs0[C]
(1)
I0 is the initial uorescence intensity without analyte. I is the the selectivity, an imprinted selectivity factor was calculated
uorescence intensity in the presence of analyte. KSV is the using the following eqn (3):
Fig. 1 Response of SiO2@dye-MIPs (a) and SiO2@dye-NIPs (b) to 2,4,6-TCP in the concentration range from 0 to 1000.0 nM.
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Fig. 2 Linear response of the SiO2@dye-MIPs (a) and SiO2@dye-NIPs (b) to 2,4,6-TCP in the concentration range from 0 to 1000 nM.
Fig. 4 Quenching amount of SiO2@dye-FMIPs and SiO2@dye-FNIPs
by different kinds of chlorophenols at 20 nmol Lꢁ1
.
background uorescence intensity without 2,4,6-TCP. If the
imprinted selectivity factor is higher than 1.0, it indicates that
the MIPs exhibited good selectivity for 2,4,6-TCP. Finally, the
imprinted selectivity factor obtained from uorescence
measurements was 2.95, which proved that SiO2@dye-FMIPs
possessed high selectivity for 2,4,6-TCP.
To further investigate the interference of 2,4-DCP, 2,5-DCP,
and 2,6-DCP, the three competitors were mixed with same
concentration of 2,4,6-TCP to form a mixture. In Fig. 5, the
uorescence intensity of the SiO2@dye-FMIPs sensor was
changed unobviously for the three competitors, and the
competitors being evaluated did not give any signicant inter-
ference. This proves again that the SiO2@dye-FMIPs sensor has
high selectivity for 2,4,6-TCP. The higher selectivity for 2,4,6-
TCP results from its specic binding affinity of 2,4,6-TCP for an
efficient imprinting effect because the same uorescence
quenching does not happen for SiO2@dye-FNIPs particles.
In order to assess the practical efficiency of the SiO2@dye-
FMIPs sensor for the analysis of food samples, soda water
purchased at Chinese supermarkets was used as a sample
Fig. 3 Time-resolved fluorescence curves of SiO2@dye-FMIPs before
(a) and after (b) adsorbing 2,4,6-TCP.
Imprinted selectivity factor ¼ (IMIP ꢁ I0)/(INIP ꢁ I0)
(3)
here, IMIP is the uorescence intensity of SiO2@dye-FMIPs material. 5.0 mL of soda water was mixed with 5 mL of 2,4,6-TCP
with 100 nM 2,4,6-TCP, INIP is the uorescence intensity of solution (concentration range 0–100 nM) and analyzed using
SiO2@dye-FNIPs with 100 nM 2,4,6-TCP, and I0 is the the procedure discussed in Section 2. The results listed in Table
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demonstrate that such a system can not only get rid of the
connes of the traditional functional monomers and detection
manner, but also improved the applications of MIPs sensors in
sensing systems.
Conflicts of interest
The authors declare no conict of interest.
Acknowledgements
This work was nancially supported by the National Natural
Science Foundation of China (No. 21576112, 21407064,
21407057, 21407059, 201407056), the Innovation Foundation
Project of Jilin Province (No. 20180623042TC), the Natural
Science Foundation Project of Jilin Province (No.
20170520143JH and 20170520147JH), the China Postdoctoral
Science Foundation (No. 2017M611732), and the Science and
Technology Development Plan of Siping City (2017056 and
2014052).
Fig. 5 Test for the interference of different chlorophenols on the
fluorescence response toward 2,4,6-TCP of SiO2@dye-FMIPs sensor.
Table 1 Recovery of 2,4,6-TCP in soda water samples at different
concentration levels
Concentration
taken (nM)
Concentration
found (nM)
Samples
Recovery (%)
References
2,4,6-TCP
0
1
2
5
10
20
50
100
—
0.98
2.19
5.13
10.22
20.87
49.13
101.45
—
98
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1 clearly demonstrate that SiO2@dye-MIPs sensor is capable of
quantitatively measuring 2,4,6-TCP content in the concentra-
tion range of 0–100 nM. The results intelligibly established that
SiO2@dye-MIPs could attain good recovery and could be effec-
tively applied in the detection of 2,4,6-TCP in soda water
samples. Compared to gas chromatography (GC),31 the method
in this work can selectively detect 2,4,6-TCP in complicated
samples without interference from analogues. In addition,
SiO2@dye-FMIPs could be used to monitor trace 2,4,6-TCP with
a lower limit of detection (0.0534 nM), while the limit of
detection for the GC method is 0.25 mg kgꢁ1, which is much
higher than the present method.
˜
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6088 | RSC Adv., 2018, 8, 6083–6089
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