Application Of Macroporous Carbon And Its Composite Materials In Electrochemical Sensor

Macroporous carbon is a new carbon material. Widespread attention have been attracted,such as in adsorption of harmful materials, in catalyst support, and as carbon electrode forsupercapacitors, due to their hydrophobic nature of their surface, high chemical inertness,good thermal and mechanical stability. Except all the excellent features mentioned above, theresulting macroporous carbon exhibits large pore size and high surface area, which can indeedprovide an ideal pathway for the efficient mass transfer and can supply more surface-activesites for the adsorption of reactants. In recent years, gold nanoparticles （GNPs） are mostextensively studied because of their unique size dependent electronic properties and excellentbiocompatibility, which were mainly applied to electrocatalysis and biosensor.We have studied the electrocatalytic of MPC, GNPs-MPC composite materials. Thedissertation mainly consists of the following two aspects:1. An electrochemical sensor based on macroporous carbon （MPC） for the detection ofluteolin was developed. MPC was dispersed in a solution of N, N-dimethylformamide （DMF）,and the suspension was modified onto the surface of glassy carbon electrode （GCE）, amacroporous carbon modified glassy carbon electrode （MPC/GCE） was obtained. Cyclicvoltammetry （CV） and different pulse voltammetry （DPV） were used to investigate theelectrochemical behaviors of luteolin on MPC/GCE. The results indicate that MPC canfacilitate the electrochemical redox of luteolin with a decrease of overpotential and a greatincrement of peak current in pH7.0phosphate buffer solution （PBS）. The MPC/GCEprovides excellent performance towards the determination of luteolin with a low detectionlimit of1.3×10^-9mol L^-1, a wide linear range from3.0×10-7to3.0×10^-5mol L^-1by differentpulse voltammetry. With such a MPC-modified electrode, the content of luteolin in capsule ofLamiophlomis rotata Kudo was successfully detected. All the results suggest that MPC/GCEwould be a stable and efficient electrochemical sensor for quality controlling and testing inmedicines and in other real samples.2. A gold nanoparticles-macroporous carbon composites modified glassy carbonelectrode （GNPs-MPC/GCE） was simply fabricated by electrodepositing GNPs film on MPCusing cyclic voltammetry （CV）. The electrochemical behaviors of of L-tryptophane （L-Trp）and L-tyrosine （L-Tyr） were studied on GNPs-MPC/GCE by Cyclic voltammetry （CV） anddifferent pulse voltammetry （DPV）. In0.1mol L^-1PBS （pH=7.4）, the GNPs-MPC/GCEexhibited satisfactory electrocatalytic activity by significantly decreasing the oxidationpotentials and increasing the peak currents of the oxidation of L-Trp and L-Tyr whencompared with those modified electrodes. All the results suggest that the present electrode gave a wide linear range from1.0×10^-5mol L^-1to1.0×10^-3mol L^-1,5.0×10^-6mol L^-1to1.0×10^-3mol L^-1, a very low detection limit of2.4×10^-8mol L^-1,7.4×10^-8mol L^-1and a highsensitivity of41μA mmol L^-1,13μA mmol L^-1for L-Trp and L-Tyr, respectively. Moreover,the electrode displayed a good reproducibility, a long-term stability and a favorable ability ofanti-interference to UA and AA.