Department of Biotechnology, Lund University, Box 124, 221 00, Lund, Sweden.
Anal Chim Acta. 2010 Feb 5;659(1-2):194-200. doi: 10.1016/j.aca.2009.11.028. Epub 2009 Nov 17.
A highly sensitive competitive capacitive glucose biosensor was constructed based on gold nanoparticles, which were employed as a platform to immobilize concanavalin A (Con A). Gold nanoparticles were fixed on a gold electrode, on which a layer of polytyramine was preformed via electrochemical polymerization. The sensing mechanism is based on the competitive dissociation of a glucose polymer or a glycoconjugate from the glycoligand binding sites of immobilized Con A by the added glucose. To further improve the sensor response, several glucose polymers as well as a synthesized glycoconjugate using the periodate method, were screened. Consequently, dextran (MW 39 kDa) was selected and the feasibility of the proposed biosensor was evaluated for a competitive assay of glucose. Experimental results show that the biosensor responded linearly to glucose in the range from 1.0 x 10(-6) to 1.0 x 10(-2) M, corresponding to 0.18 microg mL(-1) to 1.8 mg mL(-1) of glucose with a detection limit of 1.0 x 10(-6) M under optimized conditions. The studied biosensor exhibited a response time of about 15 min and a neglectable loss in sensitivity after 10 repeated analytical cycles.
基于金纳米粒子构建了一种高灵敏度的竞争性电容式葡萄糖生物传感器，该传感器将金纳米粒子用作固定伴刀豆球蛋白 A（Con A）的平台。金纳米粒子固定在金电极上，通过电化学聚合在金电极上预先形成一层聚酪氨酸。传感机制基于添加的葡萄糖从固定化 Con A 的糖基配体结合位点竞争性解离葡萄糖聚合物或糖缀合物。为了进一步提高传感器的响应，筛选了几种葡萄糖聚合物以及使用高碘酸盐法合成的糖缀合物。结果，选择了葡聚糖（MW 39 kDa），并评估了所提出的生物传感器用于葡萄糖竞争性测定的可行性。实验结果表明，该生物传感器在 1.0 x 10(-6) 至 1.0 x 10(-2) M 的范围内对葡萄糖呈线性响应，相应的葡萄糖浓度为 0.18 microg mL(-1) 至 1.8 mg mL(-1)，在优化条件下检测限为 1.0 x 10(-6) M。研究中的生物传感器具有约 15 分钟的响应时间，并且在 10 次重复分析循环后灵敏度几乎没有损失。
