Electrodes modified with nitrofluorenone derivatives as a basis for new biosensors
Electrodes modified with nitrofluorenone derivatives as a basis for new biosensors
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DOI：
10.1016/s0956-5663(01)00194-4
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发表时间：
2001-12-01
影响因子：
12.6
通讯作者：
Kuhn, A
中科院分区：
文献类型：
--
作者：
Mano, N;Kuhn, A
本文报道了硝基芴酮衍生物修饰电极的电催化性能。这些催化剂前体的稳定粘附单层可以电化学转化为相应的羟胺化合物（R-NO2 + 4 e +4 H（+）双右箭头R-NHOH + H2O）。羟胺的完全可逆的双电子氧化导致亚硝基化合物（R-NHOH双右箭头R-NO +2 e +2 H（+）），其在低过电位（-30 mV vs. Ag/AgCl）下在NADH的电氧化中表现出高催化活性，因此构成了用于生物传感器应用的有效氧化还原介体的新家族。在向电解质中加入钙离子后，观察到催化活性的显著增加（高达500%）。这可以通过辅酶的磷酸基团和催化剂分子中存在的羧基之间的特定和桥接络合来解释。这种相互作用有利于NADH与表面限制的催化剂之间的接触，从而导致更高的电子转移效率。这种相互作用可用于分子水平设计催化剂、Ca ~（2+）、NAD（+）和酶的可控单层沉积。一个非常简单和廉价的修改方案，基本上基于静电吸引，导致电极，可以采用作为无试剂生物传感器的电化学检测常见的和商业上感兴趣的分析物，如葡萄糖。(C)2001 Elsevier Science B. V.保留所有权利。
We report about the electrocatalytic properties of electrodes modified by adsorption of nitro-fluorenone derivatives. The stable, adherent monolayer of these catalyst precursors can be transformed electrochemically into the corresponding hydroxylamine compounds (R-NO2 + 4e + 4H(+) double right arrow R-NHOH + H2O). The completely reversible two electron oxidation of the hydroxylamine leads to the nitroso compounds (R-NHOH double right arrow R-NO + 2e + 2H(+)) that exhibit high catalytic activity in the electrooxidation of NADH at low overpotentials (-30 mV vs. Ag/AgCl) and therefore constitute a new family of efficient redox mediators for biosensor applications. A significant increase in catalytic activity (up to 500%) is observed after addition of calcium ions to the electrolyte. This is explained by a specific and bridging complexation between the coenzyme's phosphate groups and a carboxyl group present in the catalyst molecule. The interaction favours the contact between NADH and the surface confined catalyst, leading to a higher electron transfer efficiency. This interaction can be used in an approach of molecular level design for controlled monolayer deposition of catalyst, Ca2+, NAD(+) and enzyme. A very simple and inexpensive modification scheme, essentially based on electrostatic attraction, leads to electrodes that can be employed as reagentless biosensors for the electrochemical detection of common and commercially interesting analytes like glucose. (C) 2001 Elsevier Science B.V. All rights reserved.