Development of Sol-Gel Silicate Based Mictoarray Biosensors

溶胶-凝胶法已被证明是一种生产新型无机材料的低温技术。为了提高溶胶-凝胶酶传感器的选择性，本工作利用溶胶-凝胶酶膜和电化学生成的聚1，2-二氨基苯复合膜制备了溶胶-凝胶硅酸盐生物传感器。然而，由于酶的释放包埋在溶胶-凝胶基质中，所制备的传感器的工作稳定性较差。因此，为了防止酶的渗漏，制备的溶胶凝胶酶传感器暴露在戊二醛蒸气中。这种处理有效地提高了传感器的稳定性，但由于酶的失活而有降低灵敏度的趋势。为了改善溶胶-凝胶硅酸盐生物传感器的这些问题，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。将生物素标记的酶和亲和素的正硅酸四甲酯溶液混合在电极上，将具有4个生物素结合部位的亲和素，将多个生物素标记的酶交联并固定到硅酸盐溶胶-凝胶晶格中。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构建以葡萄糖、胆固醇、总胆固醇、尿酸盐、正磷酸盐、总正磷酸盐和氨为检测单元的多阵列生物传感器，以及构建鱼和肉的新鲜度传感器。

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.