Study On Nano-composite Sensitized Imprinted Electrochemical Sensor

Molecularly imprinted polymers (MIPs) have been approved having the some perfectproperties such as high stability, simple preparation process, high pressure resistant andspecific recognition sites for target molecules. The MIPs can improve the selectivity ofthe imprinted toward the template molecules when it was modified onto the surface ofelectrodes. Nano-materials can be used as a tool to amplify the signals due to its uniqueproperties of large specific surface area, high surface reactivity and incongruent surfaceatomic coordination. Thus, nano-composite sensitized imprinted electrochemical sensorwas prepared with the combination of MIPs with nanomaterials in the aim of obtaininghighly selective and sensitive electrochemical sensors for determination of targetcompounds. In this paper, the fabricated electrochemical sensor for determination ofbovine serum albumin and organic persistent environmental pollutants was investigated.The main contents were as follow:1. surface-imprinting sensor was prepared for bovine serum albumin (BSA)detection using chitosan-coated magnetic nanoparticles modified multi-walled carbonnanotubes (MNPs/CS-MWNTs) as a signal amplifier. The property of the MNPs/CS-MWNTs was studied using infrared spectra and their configurations were characterizedwith scanning electron microscopy. The molecularly imprinted sensor was tested bydifferential pulse voltammetry to investigate the relationship between the responsecurrent and BSA concentration. The results showed that a wide detection linear range(1.0×104~1.0×1010g mL1) for the determination of bovine serum albumin with thelow detection limit of2.8×1011g mL1for S/N=3was obtained. The surface imprintedsensor exhibited excellent selectivity, high sensitivity, and good reproducibility. Theproposed sensor also exhibited fast balance response time of30seconds, which ispropitious to rapid detect protein in spot specimens. The merits of the imprintedbiosensor suggested an attractive and broadly applicable way for developing sensors.2. A novel molecularly imprinted sensor was firstly prepared based on carbonnanotubes/graphene composite modified carbon electrode (MIPs/CNT/GP/CE) for theselective determination bovine serum albumin. The molecularly imprinted sensor wastested by differential pulse voltammetry (DPV) to investigate the relationship betweenthe response current and bovine serum albumin concentration. The results showed that awide detection linear range (1.0×104~1.0×1010g mL1) for bovine serum albumin witha low detection limit of6.2×1011g mL1for S/N=3was obtained. The novel imprintedsensor exhibited high selectivity, sensitivity, and reproducibility, which provided anapplicable way for sensors development.3. A simple strategy for the indirect detection of3,3’,5,5’-tetrabromobisphenol A(TBBPA) was developed with a surface imprinted sensor which based on electrochemical reduced graphene modified carbon electrode. The preparationprocedure of imprinted electrode and the response mechanism of the imprintedelectrode toward TBBPA were discussed in detail. The electrochemical characteristic ofthe imprinted sensor was investigated using cyclic voltammetry and their morphologieswere characterized using scanning electron microscopy. The indirect detection forTBBPA was successfully implemented by monitoring the peak current ofFe(CN)63/4–TBBPA complex. The response current exhibits a linear range between0.5and4.5nM with the detection limit of0.23nM (S/N=3). The fabricatedelectrochemical imprinted sensor was successfully applied to the detection of TBBPA inrain and lake water samples using standard addition method. With the advantages of lowcost and simple operation, the determination methodology is promising candidates forTBBPA detection in real water samples.4. A novel graphene modified-molecular imprinted was fabricated using nonyl phenolas the template molecular, polypyrrole as the functional monomer performed highselectivity and sensibility to detect. The grapheme modified molecularly imprintedsensor were characterized by the electrochemical impedance spectroscopy (EIS), cyclicvoltammetry (CV) and different pulse voltammegram (DPV). The results indicated thatthe sensor has good selectivity recognition to nonyl phenol. The linear range for theproposed sensor was1.0×1011g mL1to1.0×108g mL1,and the detection limit wasdetermined to be3.5×1012g mL1(S/N=3). Moreover, the sensor detected the realsamples rain and lake water with satisfactory results.