Development of Sol-Gel Silicate Based Mictoarray Biosensors

溶胶-凝胶法已被证明是一种低温生产新型无机材料的技术。为了提高溶胶-凝胶酶传感器的选择性，本文采用溶胶-凝胶酶膜和电化学合成的聚1,2 -二氨基苯膜复合膜制备了溶胶-凝胶硅酸盐生物传感器。然而，所制备的传感器的操作稳定性较差，因为酶被释放到溶胶-凝胶基质中。因此，为了防止捕获的酶浸出，将制备的溶胶-凝胶酶传感器暴露在戊二醛蒸气中。这种处理可以有效地提高传感器的稳定性，但由于酶失活，往往会降低传感器的灵敏度。为了改善溶胶-凝胶硅酸盐基生物传感器存在的问题，采用生物素-亲和素亲和反应制备了由溶胶-凝胶基质组成的酶受体。亲和素具有4个生物素结合位点，将多种生物素标记的酶交联固定在溶胶-凝胶硅酸盐晶格中，将生物素标记的酶和亲和素的正硅酸四甲基溶液混合在电极上。所制备的溶胶-凝胶传感器具有良好的稳定性和灵敏度。将该制备方法应用于葡萄糖、胆固醇、总胆固醇、尿酸盐、正磷酸盐、总正磷酸盐、氨等检测单元的多阵列生物传感器的构建，以及鱼类和肉类新鲜度传感器的构建。

The sol-gel method has been demostrated as a low-temperature technique for the production of new inorganic materials. In this work, sol-gel silicate-based biosensors were made by utilizing a composite membrane of sol-gel enzyme film and electrochemically generated poly(1 , 2-diaminobenzene) film to improve the selectivity of the sol-gel enzyme sensors. However, the prepared sensor was poor in operational stability, because of the release of enzyme entrapped into the sol-gel matrics. Therefore, to prevent the leaching of entrapped enzyme, the prepared sol-gel enzyme sensor was exposed to glutaraldehyde vapor. This treatment was effective to improve the stability of the sensor, but tended to decrease the sensitivity because of enzymic inactivation. To improve these problems of sol-gel silicate based biosensor, the biotin-avidin affinity reaction was adopted for the production of the enzyme receptor composed of sol-gel matrics. Avidin, having four biotin binding sites, crosslinked and immobilized enzyme labeled with multiple biotin into the sol-gel silicate lattice, when tetramethyl orthosilicate solutions of biotin labeled enzyme and avidin were mixed on the electrode. The prepared sol-gel sensors were excellent in both stability and sensitivioty. This preparation method was applied to the construction of multiarray biosensors with detection units of glucose, cholesterol, total cholesterol, and urate, and of orthophosphate, total orthophosphate, and ammonia, and the construction of freshness sensors of fish and meat.