Lin M S, Wu Y C, Jan B I
Department of Chemistry, Tamkang University, Tamsui, Taiwan, 25137.
Biotechnol Bioeng. 1999 Jan 5;62(1):56-61. doi: 10.1002/(sici)1097-0290(19990105)62:1<56::aid-bit7>3.0.co;2-m.
A cobalt(II)hexacyanoferrate-based biosensor has been prepared simply by codeposition of an enzyme, together with the electrochemical formation of a cobalt (II)hexacyanoferrate compound electrochemically. The compound can be generated at a constant potential of -0.05 V (vs. Ag/AgCl). This compound possesses the catalytic property of reducing hydrogen peroxide to water at the operating potential of 0.0 V vs. Ag/AgCl. The mixed-valence compound-based biosensor possesses an unique interference-independent feature, which is important for biomedical application; this feature is attributed to the low overvoltage characteristic of cobalt (II)hexacyanoferrate. The electrochemical glucose biosensor responds to a series of glucose injections with linearity up to 5 mM (with correlation coefficient R = 0.9999) and the sensitivity of the linear portion is 733 nA/(cm2 x mM). The detection limit is 2 x 10(-6)M (S/N = 3). Both the potential-dependent electron transfer rate constant and the apparent Michaelis-Menten constant were studied in rotating disk experiments. The apparent Michaelis-Menten constant, Km' calculated from the slope of the "Lineweaver-Burke" type reciprocal plot is 28 mM. A fast-response characteristic is observed in the rotating disk experiment and the 95% response time is 14.5 sec. No response was observed from the addition of either 2 x 10(-4)M galactose, acetaminophen, ascorbic acid, uric acid, cysteine, tyrosine, dopamine, or 1,4-dihydroxyquinone in the absence and/or in the presence of 5 x 10(-4)M glucose.
一种基于钴（II）六氰合铁酸盐的生物传感器，是通过将一种酶与钴（II）六氰合铁酸盐化合物的电化学形成共同沉积而简单制备的。该化合物可以在 -0.05 V（相对于 Ag/AgCl）的恒定电位下生成。这种化合物在相对于 Ag/AgCl 的 0.0 V 工作电位下具有将过氧化氢还原为水的催化特性。基于这种混合价化合物的生物传感器具有独特的无干扰特性，这对生物医学应用很重要；该特性归因于钴（II）六氰合铁酸盐的低过电压特性。电化学葡萄糖生物传感器对一系列葡萄糖注射呈线性响应，线性范围高达 5 mM（相关系数 R = 0.9999），线性部分的灵敏度为 733 nA/(cm2 x mM)。检测限为 2 x 10(-6)M（S/N = 3）。在旋转圆盘实验中研究了电位依赖性电子转移速率常数和表观米氏常数。从“Lineweaver - Burke”型倒数图的斜率计算出的表观米氏常数 Km' 为 28 mM。在旋转圆盘实验中观察到快速响应特性，95% 的响应时间为 14.5 秒。在不存在和/或存在 5 x 10(-4)M 葡萄糖的情况下，加入 2 x 10(-4)M 的半乳糖、对乙酰氨基酚、抗坏血酸、尿酸、半胱氨酸、酪氨酸、多巴胺或 1,4 - 二羟基醌均未观察到响应。
