Study On Electrochemical Behavior Of Amino Acids And Carbohydrates On Carbon Nanotube Based Electrodes And Its Detection

Electroanalysis is an attractive option because it is inexpensive, highly sensitive, reproductive, etc. These advantages make it widely use in chemical/biosensor. On the other hand, compared with conventional organic synthesis, there are many advantages in organic electrosynthesis, such as high purity and selectivity of products, simple process combined with low energy consumption, low pollution, etc. Nanomaterials frequently display unusual physical and chemical properties, and electrocatalysis can be considered as one of the most popular application of metal nanoparticles and carbon nanotubes (CNTs). In this paper, the potential applications of CNTs/graphite modified electrode in electroanalysis and electrosynthesis were investigated and discussed. New electrochemical sensors and new type electrodes for electrosynethesis have been developed and designed, which make high theoretical meanings and application values to exploit applications of nanomaterials. The main results are shown as follows:(1)Pt/CNTs/graphite electrode was prepared by electro-reduction of Pt(IV) complex ion on the surface of carbon nanotubes. Compared with graphite and CNTs/graphite electrodes, better electrochemical oxidation behavior of cysteine, tryptophan and tyrosine was found on Pt/CNTs/C electrode. The oxidation peaks with good features can be observed at +0.46 V, +0.52 V and. +0.54 V for cysteine, tryptophan and tyrosine, respectively. On the other hand, the sensitive sensors for these three amino acids were developed based on Pt/CNTs/graphite electrodes. The detection limit of the Pt/CNTs/C electrode for cysteine is 0.3 μM (S/N=3). Additionally, the reproducibility, stability and applicability for real samples of the Pt/CNT electrode were evaluated.(2) By oxidation of K2PtC14, a lager of Pt(IV) complex was formed on the surface of CNTs, then CuC12 solution was cast on the surface of CNT-Pt(IV) complex, and Pt(IV) and Cu(II) were co-electroreduced and Pt-Cu nanoparticles were modified on CNTs electrode. The electrocatalytic ability of Pt-Cu/CNTs/C electrode to carbohydrates is much better than that of Cu/CNTs/C and Pt/CNTs/C electrodes. Additionally, the sensitive sensors for detection of glucose, fructose and mannose were developed based on Pt-Cu/CNTs electrode and linear calibration curves can...