基于巯基己烷和纳米金组装的酪氨酸酶传感器的研制

通过自组装技术构制了一种简单有效的电流型酪氨酸酶传感器.该法先通过1,6二巯基己烷在金电极表面自组装形成有机单层,进而通过巯基与纳米金的强力相互作用将纳米金结合到电极表面形成纳米金层,最后借助纳米金的吸附作用将酪氨酸酶固定在电极表面.结果表明,酪氨酸酶能很好地保持其生物活性,所构制的传感器达到95%稳定状态电流的时间在10 s以内,3种酚类化合物测定的灵敏度顺序为:邻苯二酚>苯酚>对甲基苯酚.另外,对表观米氏常数(Kmapp)和酶电极的稳定性也进行了考察.

A TYROSINASE BIOSENSOR BASED ON HEXANEDITHIOL AND NANO-AU SELF-ASSEMBLED MONOLAYERS

An amperometric tyrosinase biosensor was developed with a simple and effective immobilization method using the self-assembled monolayers(SAMs) technique.The organic monolayer film was first formed by the spontaneous assembly of thiolor sulfur compound(1,6-hexanedithiol,HDT) from solution onto gold electrode.When these thiol-rich surfaces were exposed to Au colloid,the sulfurs form strongly bonds to gold nanoparticles,anchoring the clusters to the electrode substrate.After the assembly of gold nanoparticles layer,a new nano-Au surface was obtained.Thus,the tyrosinase could be immobilized onto the electrode.The tyrosinase retained its activity well in such an immobilization matrix.The resulting biosensor can reach 95% of steady-state current within 10 s,and the trend in the sensitivity of different phenolic compounds was as follows: catechol>phenol>p-cresol.In addition,the apparent Michaelis-Menten constant(K-m~(app)) and the stability of the enzyme electrode were estimated.