KR20150006200A - GO-MIP composite, biosensor using the GO-MIP composite and method of fabrication of the same - Google Patents

Abstract

The present invention relates to molecularly imprinted polymers including conductive graphene, biosensor using the same and a manufacturing method thereof and, more specifically, to a graphene-molecularly imprinted polymers which is selectively combined with a target biomaterial by being manufactured by a molecular imprinting technique and has excellent conductivity, to a biosensor which exhibits high sensitivity and selectivity by placing the graphene-molecularly imprinted polymers on the surface of an electrode and a manufacturing method thereof.

Description

TECHNICAL FIELD [0001] The present invention relates to a composite of graphene-molecular imprinted polymers, a biosensor containing the same, and a method of manufacturing the same.

The present invention relates to a sensor for chloramphenicol (CAP) detection, and more particularly to a GO-MIP composite of graphene oxide (GO) and molecularly imprinted polymer (MIP) And a biosensor including the same.

Electrochemical biosensors containing nanostructured materials have recently become popular due to their excellent sensitivity. Among them, many studies have been conducted on carbon-based materials such as carbon nanotubes and graphene.

'Molecularly imprinted polymer (MIP)' refers to a polymer synthesized using a suitable template material (chloramphenicol (CAP) in the present invention) and a monomer (or monomer) And then the template material is removed to leave the same space as the template material. Molecular imprinted polymers have been applied in various fields such as detection, recognition, removal, extraction, transfer and analysis of specific substances due to high selectivity and stability (Gonzalez, GP, Hernando, PF, Alegria, JSD, Anal. , 638, 209-212 et al.).

The molecular imprinting technique to obtain the molecular imprinting polymer can be applied to a solution in which monomers and a crosslinking agent are mixed and dissolved in any of the template materials to form a three-dimensional polymer structure, After removal, cavities are formed that can selectively bind to the original template material. MIP also exhibits high stability and robustness in severe synthetic and analytical environments. In the field of electrochemical sensors, MIP, which is expected to have excellent recognition and detection function for specific molecules, on the other hand, has a problem of slow moving speed and slow adsorption ability. However, by using a substance having a high surface area such as graphene, (Li, Y., Li, X., Dong, C., Qi, J., Han, X. Carbon, 2010, 48, 3427-3433 et al.).

On the other hand, as food safety issues are constantly being raised, there is a continuing need for methods that provide accurate, simple, and fast analytical results. Food is a complex analytical environment in which various obstructing substances are present. In particular, chloramphenicol (CAP), an antibiotic substance, causes side effects such as aplastic anemia, and its use is strictly restricted in the United States and Europe. (Lynas et al., Analyst, 1998, 123, 2773), the immunoassay method (Lin et al., 1998, 2005, 382, 1250), chemiluminescence (Taylor et al., J. Pharm. Biomed. Anal., 2006, 41, 347), and MIP-based assays (Shi et al., Anal. Bioanal. , et al., Analyst, 2012, 137, 3381-3389).

Although these methods provide accurate detection results, they are chemically and thermodynamically unstable (due to, for example, enzymatic action), and have the drawback of requiring long response times, high analytical costs, and complex sample preparation procedures. Also, the MIP-based method shows high selectivity, but requires expensive equipment and a difficult sample preparation process.

On the other hand, studies on the use of electrochemical means for CAP detection have been continuing (Kim et al., Biosens. Bioelectron. 2010, 25, 1781-1788 et al.). However, these methods also require a very complicated process using an immunosensor technique, and have not been satisfactory in terms of selectivity and sensitivity as a CAP sensor.

Especially, many studies have been made to solve selectivity problem in MIP based electrochemical sensor for CAP detection. For example, MIP-based nanocomposite carbon paste electrostatic field sensor (Ganjali, et al., Int. J. Electrochem. Sci., 2012, 7 4800-4810), MIP-carbon nanotube- (Zhao, et al., J. Electrochem. Soc., 2012, 159, J231-J236). The proposed methods show good selectivity, but they have disadvantages such as laboriousness of sensor manufacturing process, limit of detection time, and inaccuracy due to oxygen reduction reaction.

The present invention provides a GO-MIP complex which can be used for the production of a sensor by using a detection material with a high moving speed, excellent selectivity for a detection substance, and high conductivity, and a preparation method thereof.

The present invention also provides an electrochemical sensor and a method of manufacturing the same, which are manufactured by a simple method as a sensor for CAP detection, while exhibiting excellent sensitivity and selectivity and providing very good detection limits and reliable results.

The present invention provides a complex of molecularly imprinted polymer (MIP) (GO-MIP composite) comprising graphene oxide (GO).

Preferably, the complex is prepared by introducing a GO in the polymerization process of the molecular imprinted polymer, which is initiated from the template material and the monomer, to effect polymerization reaction.

Preferably, the template material is chloramphenicol (CAP).

Preferably, the polymerization reaction may include a cross linker.

Preferably, the graphene oxide contained in the composite is in an amount in the range of 10-90% by weight.

Preferably, the method further comprises a step of removing the template material after the polymerization reaction.

The present invention provides a biosensor comprising a complex of graphene oxide (GO) and molecularly imprinted polymer (MIP) (GO-MIP composite).

Preferably, the biosensor is manufactured by drop casting the composite on the electrode surface.

Preferably, the electrode is preferably gold (Au), platinum (Pt), or glacier carbon (GC).

Preferably, the complex is prepared by introducing graphene oxide into the polymerization process of chloramphenicol (CAP) and a molecular imprinting polymer initiated from a monomer to effect polymerization reaction.

Preferably, the complex is chloramphenicol (CAP) removed after the polymerization reaction.

Preferably, the biosensor is used for measuring the concentration of chloramphenicol contained in the sample solution in the range of pH 6.5 to 7.5.

Preferably, the biosensor is preferably a three-electrode system of a working electrode, a counter electrode, and a reference electrode.

Preferably, the thickness of the laminated structure is in the range of 0.1 m - 1 mm.

The GO-MIP composite of the graphene-molecular stamp polymer according to the present invention has a wide surface area and is excellent in electric conductivity property and can increase the immobilization amount of biomolecules such as chloramphenicol, It is possible to increase the detection sensitivity. Therefore, according to the sensor of the present invention, the selectivity to the target biomolecule (detection substance) is excellent, and by measuring the electrochemical signal, the biomaterial can be accurately detected in a large amount at a time. It is also possible to implement a detection method that can obtain reliable and accurate measured values with only a small amount of raw material.

1 schematically shows a GO-MIP composite synthesis of the present invention, the fabrication of a sensor and the process of obtaining an electrochemical signal therefrom.
2 is a SEM photograph of (a) graphene oxide (GO), (b) GO-MIP composite (before template removal) and (c) GO-MIP composite (after template removal).
3 is an isothermal N ₂ adsorption / desorption curve of (a) GO-MIP composite (before template removal) and (b) GO-MIP composite (after template removal).
4 shows electrochemical impedance spectroscopy (EIS) results of (a) bare gold electrode, (b) MIP sensor, (c) GO-MIP sensor (before template removal) and (d) GO-MIP sensor to be.
5 is a cyclic voltammogram (CV) curve for CAP of (a) bare gold electrode, (b) MIP sensor and (c) GO-MIP sensor.
6 is the first and second cycle curves of the cyclic voltammogram (CV) for the CAP of the GO-MIP sensor.
7 shows results obtained by varying the dipping time of the sensor in the sample solution (A) and the pH of the sample solution (B) for the GO-MIP sensor.
FIG. 8 is a graph showing the relationship between the GO-MIP sensor and the GO-MIP sensor; (a) 0.1 nM; (b) 1.5 nM; (c) 8 nM; (d) 20 nM; (e) 30 nM; (f) (A) the differential pulse voltammetry (DPV) curve of the sample solution containing the concentration of CAP and (B) the calibration curve according to the CAP concentration obtained using the curve.
FIG. 9 shows the results of the sensitivity test of the CAP of GO-MIP sensor and various interference substances at the same concentration of 5 μM.

The present invention relates to a molecularly imprinted polymer (MIP) composite (GO-MIP composite) comprising graphene oxide (GO), and a graphene oxide (GO) imprinted polymer (GO-MIP composite).

Molecular imprinted polymer (GO-MIP composite) containing graphene oxide (GO) "," graphene oxide (GO) "and" molecularly imprinted polymer GO-MIP composite 'and' GO-MIP composite 'are to be understood as' composite' or 'GO-MIP composite', respectively.

In order to synthesize the GO-MIP composite, the molecular imprinting technique for synthesizing molecular imprinting technique involves the use of conductive graphene in addition to the template material and the monomer to proceed the polymerization reaction. Examples of the monomer include methacrylate acid (MAA), 2-hydroxyethyl methacrylate (HEMA), acrylic acid (ACA), N -vinylpyrrolidone ( N- acrylamide (2-acrylamido-2-methyl-propanosulfonic acid (AMPS)) may be used as the polymerizable monomer, for example, vinyl pyrolidone (NVP) It is not. Mixed monomers using two or more monomers at the same time may also be used. The template material is a substance that determines the properties of the GO-MIP composite to be synthesized. In the present invention, as an example, chloramphenicol (CAP) is used as an antibiotic substance to prepare a complex that selectively binds to it. The graphene added and contained in the polymerization of the complex is specifically graphene oxide (GO). In one embodiment, the graphene oxide prepared in the form of a sheet is included in the polymerization reaction of the molecular imprinting polymer so that the reaction proceeds together. The amount of graphene oxide contained in the reaction is in the range of 10-90% by weight. When the polymer is used in an amount less than the above range, there is a problem that the composite produced has a low conductivity when applied to a sensor. When the polymer is used in an amount exceeding the above range, stability and durability of the composite may be problematic.

A crosslinking agent may be used in the polymerization reaction. This crosslinking agent is ethylene glycol dimethacrylate (ethyleneglycol dimethacrylate (EGMA)), ethylene methacrylate (ethylene dimethacrylate (EDMA)), N, N - methylene bisacrylamide (N, N -methylenebisacrylamide (MBAA) ), Divinyl benzene (DVB) may be used, but is not limited thereto. Mixed crosslinking agents using two or more crosslinking agents simultaneously may also be used. Further azobisisobutyronitrile to the start of the reaction (azobisisobutyronitrile (AIBN)), ammonium peoseol rate (ammonium persulfate (APS)), N, N, N ', N' - tetramethylenediamine (N, N, N ' , N '-tetramethylenediamine available initiators like (TEMED)), but without being limited thereto.

The composite prepared by the above method contains a template material. The preparation of a complex that selectively binds to the template material is completed by removing the template material from the composite. For this purpose, extraction is carried out using a mixed solution of ethanol and acetic acid. The composite in which the template material has been removed increases porosity by increasing the diameter and volume of the pores.

Next, the present invention provides a method of applying the composite to the manufacture of a sensor as shown in FIG. 1 and a sensor manufactured therefrom. In order to fabricate the sensor, the present invention uses a method of forming a laminate structure of a composite by drop casting a solution containing the composite on the electrode surface. However, the present invention is not limited thereto, but can be used if it is a method capable of forming a laminated structure having a desired thickness for detection of a target substance according to the viscosity of a solution or the like. The solution is preferably such that the amount of graphene oxide is in the range of 10-90 wt%, and the thickness of the laminated structure is in the range of 0.1 μm - 1 mm. If the concentration is too low or too high, a laminate structure of desired thickness and density is not formed. That is, when the concentration of the solution is too low, the solution spreads too fast on the electrode surface to form a laminate structure having an appropriate thickness and density. Conversely, if the concentration is too high, the solution does not spread on the electrode surface, .

Preferably, the laminated structure formed by drop casting is used as a working electrode of the sensor through a drying process.

The sensor of the present invention uses the prepared electrode as a working electrode and preferably uses a three-electrode system including a counter electrode and a reference electrode for the configuration of the sensor. As the working electrode, gold (Au), platinum (Pt), or glacier carbon (GC) may be used. As the counter electrode and the reference electrode, platinum wire and Ag / AgCl may be used.

A cyclic voltammetry (CV) method is used for the detection of the target substance from the sensor of the present invention as shown in FIG. In one embodiment, the concentration can be measured by the peak current value on the curve 'CV curve' obtained by the oxidation and reduction reaction of chloramphenicol in FIG.

Hereinafter, the present invention will be described in more detail by way of examples. These embodiments are only for illustrating the present invention, and thus the scope of the present invention should not be construed as being limited by these embodiments.

Example

1. Preparation of graphene oxide sheet

1 g of graphite powder was placed in 23 ml of 98% H ₂ SO ₄ and stirred at room temperature for 24 hours. After putting 100 mg of NaNO ₃ in the mixture is stirred for 30 minutes and stored in an ice bath to below 5 ℃. After 3 g of KMnO ₄ was added slowly, the mixed solution was heated to 40 ° C and stirred for 30 minutes. Then, 46 ml of water was added and the mixture was reacted for 30 minutes. Finally, 140 mL of water and 10 mL of 30% H ₂ O ₂ were added to stop the reaction. After the unused graphite was removed by centrifugation, the synthesized graphene oxide was dispersed in a sheet form in distilled water at a concentration of 1 mg / mL. The gray precipitate was washed several times with ethanol and water, and dried to obtain a graphene oxide sheet.

2. Synthesis of graphene oxide-chloramphenicol (CAP) imprinted polymer composite (GO-MIP composite) and MIP synthesis and removal of template material

0.1 mmol of CAP was dissolved in 10 mL of tetrahydrofuran (THF, porogen), and a mixture of separately prepared 0.4 mmol of methacrylic acid (MAA, monomer) and 2 mmol of ethyleneglycol dimethacrylate (EGMA, crosslinking agent) was added. Then, 8 mg of azobisisobutyronitrile (AIBN, polymer initiator) was added. 55 mg of graphene oxide was dispersed in the mixture and sonicated for 10 minutes. The resultant was then incubated in a water bath and the polymerization reaction was allowed to proceed while stirring slowly at 60 DEG C for 20 hours.

After 20 hours, the residue was washed with ethanol to remove the template material from the GO-MIP composite prepared above and extracted with a magnetic stir bar for 10 hours with a mixture of ethanol: acetic acid (90:10 v / v%). The resultant was washed again with acetonitrile and water and then dried.

On the other hand, the MIP was synthesized in the same manner except that the step of introducing GO into the mixture was omitted for comparison.

3. Fabrication of sensor

The sensor was fabricated by stacking the GO-MIP composite (before and after removing the template material) and the MIP on the gold electrode. For this purpose, the gold electrode surface was polished with alumina-water slurry and washed with distilled water. The prepared GO-MIP composite and MIP were dispersed in THF (4 mg / mL) and dropped onto the electrode using a pneumatic dispenser (EFD model 1000XL). And dried at 40 DEG C for 2 hours to obtain an electrode surface having a uniform and dried layer structure. This was used as working electrode in the following sensor configuration.

Experimental Example

1. GO-MIP composite surface evaluation

To evaluate the surface properties of the synthesized GO-MIP composite, S-4700 II (Hitachi, Tokyo, Japan) S-4700 (SEM) II). FIG. 2A is a photograph of a graphene oxide sheet for comparison. Here, a corrugated and loosened surface is confirmed due to the opening of the carbon network by oxidation. Next, GO-MIP Particles with an average diameter of 40-50 nm were observed on the surface of the GO-MIP composite after removal of the template material, The porous surface with the same pinhole was shown, while the porous material was less porous prior to the removal of the template material, thus showing a smoother surface. On the other hand, in the photograph of the GO-MIP composite surface of the present invention The GO-MIP composite according to the present invention can be used as a template material (CAP) because it is easy to pass through the matrix material (CAP) Lt; RTI ID = 0.0 > affinity < / RTI > and selectivity.

2. Porosity evaluation of GO-MIP composite

Next, the N ₂ adsorption and desorption experiments (Brunauer-Emmett-Teller (BET) analysis) and the TriStar 3000 gas adsorption analyzer (Micromeritics, Norcross, GA) were performed to evaluate the porosity of the GO- USA)). The experimental results are shown in Fig. The diameters and the volumes of pores calculated from these are shown in Table 1 below.

Sample BET surface area (m ² / g) Average pore diameter
(BJH adsorption)
(nm) Pore volume
(BJH adsorption)
(cm < ³ > / g) GO-MIP
(Before removing the template material)

GO-MIP
(After removing the template material) 393.32



651.20 4.1



8.6 0.24



0.75

From the above table, it can be seen that the average diameter and volume of the pores of the GO-MIP composite were improved after the removal of the template material, thereby increasing the surface area.

3. Evaluation of conductivity of sensor

In order to evaluate the impedance and conductivity of the fabricated sensor, a bare gold electrode (a), an MIP sensor (b), a GO-MIP sensor (before removing the template) (c) Electrochemical impedance spectroscopy (EIS) Nyquist plot (CH Instruments electrochemical analyzer 600B, frequency range: 100 mHz-100 kHz, potential: 0.2 V, AC voltage: 5 mV) The impedance of the GO-MIP sensor (FIG. 4C) before the removal of the template material was higher than that of the bare gold electrode (FIG. 4A), but the impedance was significantly decreased after removing the template material (FIG. That is, the pores formed due to the removal of the template material drastically improve the electron mobility. On the other hand, the impedance is the largest in the MIP sensor (FIG. 4B), which is a natural result because it does not include a conductive GO.

4. Electrochemical characterization of sensor

Bare electrode, MIP sensor and GO-MIP sensor were immersed in 5 μM of CAP solution for 4 minutes, washed with water, and scanned at a rate of 50 mV / s in 0.1 M phosphate-buffered saline (PBS buffer, pH 7.0) A CV curve (counter electrode: Pt wire, reference electrode: Ag / AgCl) as shown in Fig. 5 was obtained. No peak appeared at the bare electrode (Fig. 5A), and a small cathodic peak (near -0.65 V) was observed at the MIP sensor (Fig. 5B) and at the GO-MIP sensor appear. From this, it can be seen that the presence of graphene oxide in the MIP improves the electron mobility and contributes to the enhancement of the affinity of CAP.

5. Optimization of sensor

(1) Selection of detection peak

On the other hand, according to the CV curve (FIG. 6) of the CAP obtained from the GO-MIP sensor, the cathodic peak (first cathodic peak) at -0.65 V becomes large in the first cycle and sharply decreases in the next cycle. (Second cathodic peak) and an anodic peak at 0.08 V stably appear. This is the result of the redox reaction of CAP as shown in Figure 1, where the first cathodic peak is due to the irreversible reduction of the nitro group (-NO ₂ ) of the CAP to the hydroxylamine group (-NHOH) A stable second cathodic peak and anodic peak appear due to the reversible oxidation and reduction between the hydroxylamine group (-NHOH) and the nitroso group (-NO).

On the other hand, the current at the first catodic peak is larger than the anodic peak and the second catodic peak, but the first catodic peak is susceptible to the oxidation of oxygen. Therefore, it is preferable to use the oxidation peak at 0.08 V, which is not affected by the oxidation of oxygen and in which a relatively large current flow is observed, for the detection of CAP.

(2) Optimization of dipping time in sample solution

The GO-MIP sensor was immersed in a sample solution containing 5 μM of CAP for 1 to 7 minutes to obtain a CV curve, and the current at the anodic peak was measured. The results are shown in Fig. 7A. It can be seen that the magnitude of the current no longer increases after 4 minutes. Therefore, the dipping time was 4 minutes.

(3) Determination of the pH of the sample solution

For the GO-MIP sensor, CV curves were obtained on a buffer solution that was otherwise adjusted to a pH in the range of 5.0 to 9.0 by mixing NaH ₂ PO ₄ -Na ₂ HPO ₄ and the current at the anodic peak was measured. As a result, as shown in Fig. 7B, the current was large in the range of pH 6.5 to 7.5. This is because as the pH of the solution increases from 5.0 to 7.0, the reduction from the -NO ₂ group to the -NHOH group of the CAP is increased, while the increase is increased to 8.0 or 9.0. Therefore, the pH of the solution for CAP detection was determined to be 7.0.

6. Sensitivity evaluation of sensor

For the GO-MIP sensor of the present invention, the CV curve was obtained while changing the concentration of the CAP solution from 90 nM to 0.1 nM, and the current at the anodic peak was measured. Each current was measured in the second cycle. In the measurement of each concentration, the sensor was subjected to elution with ethanol (6 minutes) to remove the template material, CAP. The results are shown in Figs. 8A and 8B. As a result, the current value linearly increased with CAP concentration (correlation coefficient r ² = 0.9987) and the detection limit was very low, 35 ± 2 pM (RSD <5%).

7. Evaluation of the effect of interfering substances

To evaluate the effect of other interfering substances in the sample solution, that is, the selectivity for CAP in the GO-MIP sensor of the present invention, thiamphenicol (TAP), ampicillin , AMP) tetracycline (TET) p-nitrophenol (p-NP), 2,4-dinitrophenol (DNP), sulfadimethoxine Ascorbic acid (AA), uric acid (UA), riboflavin (Vit.B2) and pyridoxine (Vit.B6) were selected. FIG. 9 shows the results of comparing the sensitivity of the GO-MIP sensor CAP and various obstructing substances at the same concentration of 5 μM. Signals from all the interferents were significantly lower than CAP. From this, it can be confirmed that the GO-MIP sensor of the present invention can detect CAP with high selectivity even in the presence of an interfering substance.

8. Performance evaluation of sensor for milk sample

The performance of the GO-MIP sensor of the present invention was evaluated for milk samples containing CAP at 0.5, 1.0, 5.0, and 10.0 nM concentrations. A 10 mL sample was placed in a centrifuge tube and an appropriate amount of acid was added to obtain a precipitate of the protein. The mixture was centrifuged at 1000 rpm for 10 minutes to discard the upper and lower layers, and the intermediate layer was filtered. The filtered solution was transferred to a cell containing 0.1 M PBS, the concentration was measured with a GO-MIP sensor and the CAP recovery was calculated from the measured values.

Sample CAP (nM)
Addition amount Recovery rate (%) RSD (%) One
2
3
4 0.5 0.48 0.02
1.0 0.97 + 0.03
5.0 4.90 0.10
10.0 9.51 + - 0.40 96
97
97
95 4.16
3.10
2.04
4.20

From the table it can be seen that the sensor of the present invention provides reliable measurement results for real samples.

9. Evaluation of the stability of the sensor

After storage for a long time in electrolyte (0.1 M PBS, pH 7.0, room temperature), the stability of the sensor was evaluated by testing the performance of the sensor. As a result, the sensitivity was preserved 96% after 1 week, 70% and 50% after 2 weeks and 3 weeks, respectively, and the sensitivity was lost after 4 weeks.

In order to evaluate the reliability of the sensor in repetitive measurement, it was repeated 10 times for one sample. The result showed a RSD of 0.8%. From this, it was confirmed that the sensor of the present invention does not cause fouling of the surface of the sensor electrode during analysis, and thus can provide a reliable result.

10. Sensitivity comparison with other sensors

Table 3 compares the detection limit of various other sensors used in the CAP measurement with the detection limit of the sensor of the present invention.

Sensor type Detection limit Reference Bare Gold Electrode 1 μM Sanaz Pilehvar, Freddy Dardenne, Ronny Blust, Karolien De Wael, Int. J. Electrochem. Sci., 7 (2012) 5000 -5011 Nano-composite of MWCNTs / nanosilica / graphite powder / Ionic Liquids 11 μM M.R. Ganjali, T. Alizade, P. Norouzi, Int. J. Electrochem. Sci., 7 (2012) 4800-4810 A batch-type antibody-immobilized quartz crystal microbalance (QCM) 10 μM (10 ^-5 M) Park et al., Biosensors and Bioelectronics 19 (2004) 667-674 MIP / c- MWNTs-AuNPs 24 nM Huimin Zhao, Yaqiong Chen, Junping Tian, Hongtao Yu, and Xie Quan, Journal of The Electrochemical Society, 159 (6) J231-J236 (2012) Disposable
Wall-Jet Ring Disk Carbon Electrode with FIA (flow injection analysis) 74 nM Liao et al., Electroanalysis 19 (2007) 65-70 Amperometric immunosensor based on Anti-CAP antibody on CdS modified-dendrimer conjugated to the conducting polymer 45 pg / mL
(~ 140 pM) Kim et al., Biosen. Bioelectron. 25, 2010, 1781 Activated cylindrical carbon fiber microelectrodes 47 nM (4.7 x 10 &lt; ^-8 &gt; M) L. Agui, A. Guzman, P. Yanez-Sedeno, J.M. Pingarron, Analytica Chimica Acta 461 (2002) 65-73 Boron-doped Diamond Electrode with FIA 0.03 [mu] M Suchada CHUANUWATANAKUL, * Orawon CHAILAPAKUL, Shoji MOTOMIZU, ANALYTICAL SCIENCES APRIL 2008, VOL. 24, 493-498 Ant-CAP immobilized on amino-silane modified beads immunoassay in PDMS channels 8 pM Zhang et al., J. Agric. Food Chem. 2008, 56, 9862-9867 Method based on
LC-ESI-MS-MS 100 pM Bogusz et al., J. Chromatogr. B, 807 (2004) 343-356 Composite of SWCNTs / AuNPS / Ionic Liquid 1 nM Xiao et al., Anal. Chim. Acta 596, 2007, 79 Graphene-MIP based composite 35pM (based on oxidation peak) The sensor

MSA: mercaptosuccinic acid

SATUM: Self-assembled thiourea monolayer

From the above table it can be seen that the sensor of the present invention has a very low detection limit compared to other sensors.

Claims (16)

A GO-MIP composite of a molecularly imprinted polymer (MIP) characterized by comprising graphene oxide (GO). The method of claim 1,
Wherein the graphene oxide contained in the composite is in the range of 10-90 weight% (GO-MIP composite). (GO-MIP composite) which is produced by introducing graphene oxide (GO) into a polymerization process of a molecular imprinting polymer initiated from a template material and a monomer to effect polymerization reaction. . 4. The method of claim 3,
Characterized in that the template material is chloramphenicole (CAP). &Lt; Desc / Clms Page number 20 &gt; 4. The method of claim 3,
The monomers methacrylic acid (methacrylate acid (MAA)), 2- hydroxyethyl methacrylate (2-hydroxyethyl methacrylate (HEMA) ), acrylic acid (acrylic acid (ACA)), N - vinylpyrrolidone (N -vinyl 2-acrylamido-2-methyl-propanosulfonic acid (AMPS), acrylamide (AAM) and pyrolidone (NVP) (GO-MIP composite) comprising at least one graft-molecular imprinting polymer. 4. The method of claim 3,
The polymerization is azobisisobutyronitrile (azobisisobutyronitrile (AIBN)), ammonium peoseol rate (ammonium persulfate (APS)) and N, N, N ', N ' - tetramethylenediamine (N, N, N ', N ' -Tetramethylenediamine (TEMED)). The method of claim 1, wherein the crosslinking agent is selected from the group consisting of: 4. The method of claim 3,
The polymerization is azobisisobutyronitrile (azobisisobutyronitrile (AIBN)), ammonium peoseol rate (ammonium persulfate (APS)) or N, N, N ', N ' - tetramethylenediamine (N, N, N ', N -Tetramethylenediamine &lt; / RTI &gt; (TEMED). & Lt; / RTI &gt; 4. The method of claim 3,
And then removing the template material after the polymerization reaction. The method for producing a complex of graphene-molecular stamp polymer (GO-MIP composite) according to claim 1, (GO-MIP composite) of graphene-molecular-imprinting polymer. The method of claim 9,
Wherein said complex (GO-MIP composite) is polymerized by introducing graphene oxide (GO) during the polymerization of chloramphenicol (CAP) and a molecular imprinting polymer initiated from the monomer. 11. The method of claim 10,
Wherein said complex (GO-MIP composite) is prepared by removing chloramphenicol (CAP) after polymerization. 12. The method of claim 11,
Wherein the biosensor is used for measuring the concentration of chloramphenicol contained in the sample solution in the range of pH 6.5 to 7.5. The method of claim 9,
Wherein the biosensor includes a working electrode, a counter electrode, and a reference electrode. Wherein a solution containing a graphene-molecular imprinted polymer (GO-MIP composite) is drop-cast on the electrode surface to form a laminated structure. The method of claim 14,
Wherein the electrode is preferably gold (Au), platinum (Pt), or glacial carbon (GC). The method of claim 14,
Wherein the thickness of the laminated structure is in the range of 0.1 m - 1 mm.

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