关键词:  , L-半胱氨酸和胱胺；共自组装膜；抗坏血酸；抗吸附；活体

Abstract: Self-assembled monolayers (SAMs), which form highly ordered monolayers on the electrode surface through the gold-suffer bond, have attracted much attention in recent years. This stable layer not only can regulate the wettable properties of surface, but also can act as a promoter towards redox-active molecules. Here, we developed a simple and effective method to construct cysteine and cystamine co-self-assembled monolayer on gold microelectrode for  in vivo detection of ascorbic acid (AA). The molar ratio at 1:1 of mixed monolayer has been found the optimum to enhance the electron-transfer kinetics of AA oxidation at low potential (ca. 0.10 V), meanwhile, it could resist the non-specific adsorption of protein at electrode surface. The application of the co-self-assembled monolayer is preliminarily demonstrated for  in vivo detection and the basal level of striatum AA was determined to be 257 ± 30 mmol·L^-1 (n = 3). This study offers a general and effective approach for  in vivo electrochemistry with high reliability and simplified procedures.

Key words:  cysteine and cystamine, co-self-assembled monolayer, ascorbic acid, anti-adsorption, in vivo