Liu Z, Liu B, Kong J, Deng J
Department of Chemistry, Fudan University, Shanghai, People's Republic of China.
Anal Chem. 2000 Oct 1;72(19):4707-12. doi: 10.1021/ac990490h.
A novel tyrosinase biosensor has been developed for the subnanomolar detection of phenols, based on the immobilization of tyrosinase in a positively charged Al2O3 sol-gel membrane on a glassy carbon electrode. It has been found that Al2O3 sol-gel is perfectly beneficial to the immobilization of tyrosinase, because it not only possesses the general advantages of sol-gel but it also is an effective promoter of the biosensor. The large microscopic surface area, porous morphology, and hydrophilic property of the sol-gel matrix result in high enzyme loading, and the enzyme entrapped in this matrix retains its activity to a large extent. The Al2O3 sol-gel-containing surface also displays an intrinsic electrocatalytic o-quinone response and, hence, offers a high-sensitivity (127 microA mM(-1)) monitoring of phenols. The detection limit is 0.2 nM at a signal-to-noise ratio of 3, the response time is less than 4 s reaching 95% of the steady-state value, and 70% of the activity is retained after 3 months.
基于将酪氨酸酶固定在玻碳电极上带正电荷的氧化铝溶胶 - 凝胶膜中，已开发出一种用于亚纳摩尔级检测酚类的新型酪氨酸酶生物传感器。已发现氧化铝溶胶 - 凝胶对酪氨酸酶的固定非常有利，因为它不仅具有溶胶 - 凝胶的一般优点，而且还是生物传感器的有效促进剂。溶胶 - 凝胶基质的大微观表面积、多孔形态和亲水性质导致高酶负载量，并且包埋在该基质中的酶在很大程度上保留其活性。含氧化铝溶胶 - 凝胶的表面还显示出固有的邻醌电催化响应，因此能够对酚类进行高灵敏度（127 μA mM⁻¹）监测。在信噪比为3时检测限为0.2 nM，响应时间小于4 s即可达到稳态值的95%，并且3个月后仍保留70%的活性。
