Ohnuki Hitoshi, Saiki Takafumi, Kusakari Akira, Endo Hideaki, Ichihara Masaki, Izumi Mitsuru
Faculty of Marine Technology, Tokyo University of Marine Science and Technology, 2-1-6 Etchujima, Koto-ku, Tokyo 135-8533, Japan.
Langmuir. 2007 Apr 10;23(8):4675-81. doi: 10.1021/la063175g. Epub 2007 Mar 17.
Glucose oxidase (GOx) was immobilized in the organic-inorganic Langmuir-Bldogett (LB) films consisting of octadecyltrimethylammonium (ODTA) and nanosized Prussian blue (PB) clusters. The amperometric glucose biosensors based on the LB films were fabricated and tested. It was found that the sensors exhibited a clear response current under an applied voltage of 0.0 V (vs Ag/AgCl). The linearity of current density versus glucose concentration was confirmed below 15 mmol/L concentration. This is the first observation of biosensor function of the hybrid organic-inorganic LB films. The successful preparation of glucose sensors operating at the very low potential indicates that the adsorbed PB clusters in the LB films act as an electrocatalyst for the electrochemical reduction of hydrogen peroxide, which is the final product of the enzymatic reaction sequence. The observed low potential applicability is estimated to inhibit the responses of interferants such as ascorbic acid, uric acid, and acetominophen. It was also found that an electrostatic interaction between positively charged ODTA+ and the adsorbed species of both GOx and PB provided a stabilized adsorption state in the LB films. Such stable immobilization contributes to the steady amperometric response current observed in the present ODTA/PB/GOx LB films.
葡萄糖氧化酶（GOx）被固定在由十八烷基三甲基铵（ODTA）和纳米级普鲁士蓝（PB）簇组成的有机-无机朗缪尔-布洛杰特（LB）膜中。制备并测试了基于LB膜的安培型葡萄糖生物传感器。结果发现，该传感器在0.0 V（相对于Ag/AgCl）的外加电压下表现出明显的响应电流。在浓度低于15 mmol/L时，电流密度与葡萄糖浓度的线性关系得到确认。这是首次观察到混合有机-无机LB膜的生物传感器功能。成功制备出在极低电位下工作的葡萄糖传感器，这表明LB膜中吸附的PB簇作为过氧化氢电化学还原的电催化剂，而过氧化氢是酶促反应序列的最终产物。观察到的低电位适用性估计可抑制抗坏血酸、尿酸和对乙酰氨基酚等干扰物的响应。还发现带正电的ODTA⁺与GOx和PB的吸附物种之间的静电相互作用在LB膜中提供了稳定的吸附状态。这种稳定的固定化有助于在当前的ODTA/PB/GOx LB膜中观察到稳定的安培响应电流。
