The Development Of Electrochemical Sensors Based On Large Mesoporous Carbon And Their Application

Electrochemical sensor is widely used in the fields of food and drug monitoring becauseof its unique advantages. In order to develop new principles and new methods for drugs andfood detection, scientists have been satisfied with combined carbon nanomaterials withelectrochemical techniques. In this paper, two kinds of large mesoporous carbon-basedcomposites were employed as electrode modified materials for electrochemical studies andquantitative examination of theophylline in beverages and human body fluids. The majorcontents are described as follows:1. A novel theophylline (TP) sensor was developed using single-walled carbonnanotubes-large mesoporous carbon/Nafion composites modified glassy carbon electrode(SWCNTs-LMC/Nafion/GCE). The morphology of SWCNTs-LMC microstructure wascharacterized by transmission electron microscopy (TEM) and the surface of the modifiedelectrode was characterized by CV. The results showed enhanced electrochemical reactivityand voltammetric response of TP. Under the selected conditions the peak current was in linearwith TP concentration from0.3to38.0μM with the detection limit as0.08μM (S/N=3) byDPV. The SWCNTs-LMC/Nafion/GCE was successfully applied for the determination of TPin human blood serum and urine samples with good recoveries.2. A glassy carbon electrode (GCE) modified with large mesoporous carbon and Nafioncomposites (LMC/Nafion) was constructed and used for simultaneous determination oftheophylline (TP) and caffeine (CF). The electrochemical behaviors of TP and CF on theLMC/Nafion/GCE were carefully investigated by cyclic voltammetry (CV) and differentialpulse voltammetry (DPV). The results show that the DPV peaks of the two analytes can bedistinguished at the modified electrode with peak-to-peak separation about150mV, whichmeans that LMC/Nafion/GCE is suitable for simultaneous determination of TP and CF. Underthe optimized condition, the detection limits of TP and CF were0.37and0.47μM (S/N=3)with linear ranges of0.8-180.0μM and1.3-230.0μM, respectively. The proposed method wassuccessfully applied to the simultaneous determination of TP and CF in human blood serumand beverages with reliable recovery.