Detection of glucose at 2 fM concentration.
Detection of glucose at 2 fM concentration.
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DOI：
10.1021/ac0486746
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发表时间：
2005-01
影响因子：
7.4
通讯作者：
N. Mano;A. Heller
中科院分区：
文献类型：
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作者：
N. Mano;A. Heller
我们报告的安培检测葡萄糖在2 fM浓度的生理缓冲溶液中，在1个大气压的氧气压力。灵敏的测定是基于接近绝对的电还原剥离的O2从附近的葡萄糖电氧化阳极的溶液。葡萄糖通过其在被也固定的铂环包围的固定的玻璃碳盘上的电氧化来检测。该盘涂覆有葡萄糖氧化酶（GOx）的膜，该膜与PVP-[Os（N，N '-二甲基-2，2'-联咪唑）3]2+/3+（聚合物I）电“连接”，相对于Ag/AgCl具有-0.19V的氧化还原电位。该环涂覆有胆红素氧化酶（BOD），其与PAA-PVI-[Os（4，4 ′-二氯-2，2 ′-联吡啶）2Cl]+/2+（聚合物II）“连接”，相对于Ag/AgCl具有+0.36 V的氧化还原电位。将环-盘电极保持面朝上，并将30 μ L液滴置于其上用于测定，环保持在-0.3V/ AgAgCl，盘保持在-0.1V/ Ag/AgCl。尽管液滴上方的气氛是1个大气压下的O2，但有线BOD盘有效地清除了O2，使得GOx的葡萄糖还原的FADH 2不会被O2氧化，O2是酶的天然共底物。
We report the amperometric detection of glucose at 2 fM concentration in a physiological buffer solution at 1 atm O2 pressure. The sensitive assay is based on the close to absolute electroreductive stripping of O2 from the solution near the glucose electrooxidizing anode. The glucose was detected by its electrooxidation on a stationary glassy carbon disk surrounded by an also stationary platinum ring. The disk was coated with a film of glucose oxidase (GOx), electrically "wired" with PVP-[Os(N,N'-dimethyl-2,2'-biimidazole)3]2+/3+ (polymer I), having a redox potential of -0.19 V versus Ag/AgCl. The ring was coated with bilirubin oxidase (BOD) "wired" with PAA-PVI-[Os(4,4'-dichloro-2,2'-bipyridine)2Cl]+/2+ (polymer II), having a redox potential of + 0.36 V versus Ag/AgCl. The ring-disk electrode was held facing up, and a 30-microL drop was placed on it for the assay, with the ring poised at -0.3 V/ AgAgCl and the disk poised at -0.1 V/ Ag/AgCl. Even though the atmosphere over the drop was O2 at 1 atm pressure, the wired BOD disk scavenged the O2 so effectively that the glucose-reduced FADH2 of GOx was not oxidized by O2, the natural cosubstrate of the enzyme.