A triethylene glycol modified glassy carbon electrode （TEG-GCE） was fabricated by a controlled- potential electrolysis procedure. The performance of the film on the modified electrode surface was investigated by cyclic voltammetry with different probes. It was firstly found that while neutral pieces could penetrate the TEG film on the GCE surface, the ionic pieces, whatever it is anion or cation, was blocked by the film. This property was successfully used for determining dopamine （DA） in the presence of ascorbic acid （AA） with differential pulse voltammetry （DPV）.
A novel electrochemical sensor based on the immobilization of tyrosinase（tyr） onto gold nanoparticles（nano-Au） and thioctic acid amide（T-NH2） self-assembled monolayers（SAMs）-modified gold electrode has been developed for the determination of bisphenol A（BPA）.It was found that the nano-Au could significantly enhance the electrochemical response of tyr/nano-Au/T-NH2/Au electrode to BPA,and the enhancement effect of nano-Au on the current response was also related to the enzyme.The results indicated that the biosensor could be used as a detector for BPA determination with a linear range from3.99 ×10-7mol/L to 2.34 ×10-4mol/L and a detection limit of 1.33×10-7mol/L.In addition,this biosensor showed good reproducibility.
Na WangHai-Yan ZhaoXue-Ping JiXian-Rui LiBei-Bei Wang
