Liu Songqin, Ju Huangxian
Department of Chemistry, Institute of Analytical Science, State Key Laboratory of Coordination Chemistry, Nanjing University, Nanjing 210093, China.
Biosens Bioelectron. 2003 Nov 30;19(3):177-83. doi: 10.1016/s0956-5663(03)00172-6.
The direct electrochemistry of glucose oxidase (GOD) adsorbed on a colloidal gold modified carbon paste electrode was investigated. The adsorbed GOD displayed a pair of redox peaks with a formal potential of -(449+/-1) mV in 0.1 M pH 5.0 phosphate buffer solution. The response showed a surface-controlled electrode process with an electron transfer rate constant of (38.9+/-5.3)/s determined in the scan rate range from 10 to 100 mV/s. GOD adsorbed on gold colloid nanoparticles maintained its bioactivity and stability. The immobilized GOD could electrocatalyze the reduction of dissolved oxygen and resulted in a great increase of the reduction peak current. Upon the addition of glucose, the reduction peak current decreased, which could be used for glucose detection with a high sensitivity (8.4 microA/mM), a linear range from 0.04 to 0.28 mM and a detection limit of 0.01 mM at a signal-to-noise ratio of 3sigma. The sensor could exclude the interference of commonly coexisted uric and ascorbic acid.
研究了吸附在胶体金修饰碳糊电极上的葡萄糖氧化酶（GOD）的直接电化学。在0.1 M pH 5.0磷酸盐缓冲溶液中，吸附的GOD呈现出一对形式电位为-(449±1) mV的氧化还原峰。该响应显示为表面控制的电极过程，在10至100 mV/s的扫描速率范围内测定的电子转移速率常数为(38.9±5.3)/s。吸附在金胶体纳米颗粒上的GOD保持其生物活性和稳定性。固定化的GOD可电催化溶解氧的还原，并导致还原峰电流大幅增加。加入葡萄糖后，还原峰电流降低，可用于高灵敏度（8.4 μA/mM）的葡萄糖检测，线性范围为0.04至0.28 mM，在信噪比为3σ时检测限为0.01 mM。该传感器可排除常见共存尿酸和抗坏血酸的干扰。
