Electrocatalytic activity of carbon spheres towards NADH oxidation at low overpotential and its applications in biosensors and biofuel cells
Electrocatalytic activity of carbon spheres towards NADH oxidation at low overpotential and its applications in biosensors and biofuel cells
复制标题
低过电位碳球对NADH氧化的电催化活性及其在生物传感器和生物燃料电池中的应用
DOI：
10.1039/c1ra00444a
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发表时间：
2011-01-01
期刊：
影响因子：
3.9
通讯作者：
Wang, Lun
中科院分区：
文献类型：
--
作者：
Gao, Feng;Guo, Xinying;Wang, Lun
研究了一种新型的微结构碳材料--碳空心球（CS）对二氢烟酰胺腺嘌呤二核苷酸（NADH）氧化的电催化活性。与传统的裸玻碳电极相比，使用CS涂层观察到NADH电氧化的过电位大幅降低450 mV，氧化开始于约100 mV。-0.10 V（相对于Ag/AgCl，pH 7.0）。因此，CS涂覆的玻璃碳电极（CS/GC）允许在较低电位下以7.3 +/-0.2 nA mu M-1的高灵敏度（即，103.3 +/- 2.8 nA μ M-1 cm（-2）），低检测限为0.08 +/- 0.03 μ M，并使表面结垢最小化。以乳酸脱氢酶（LDH）为模型，构建了具有LDH-CS/GC电极的乳酸生物传感器，该生物传感器对0.5 - 12 mM的乳酸具有快速和高灵敏度的安培响应，检测限为3.7 ± 0.2 μ M，灵敏度为4.1 ± 0.2 nA μ M-1（即，57.9+/- 2.8 nA μ M-1 cm（-2）），重现性好，稳定性好。进一步研究了胆红素氧化酶（BOD）在CS/GC电极上的直接电子转移（DET）促进作用，以LDH-CS/GC为乳酸氧化阳极，BOD-CS/GC为氧还原电极，组装了无膜乳酸/氧生物燃料电池，具有0.60 V的高开路电位。CS降低NADH氧化过电位并促进蓝-铜氧化酶为基于铜氧化酶的电流生物传感器和生物燃料电池提供了巨大的前景。
The excellent electrocatalytic activity of a micro-structured carbon material, carbon hollow spheres (CS), to the oxidation of dihydronicotinamide adenine dinucleotide (NADH) is demonstrated here. Compared to conventional bare glassy carbon electrodes, a substantial decrease by 450 mV in the overpotential of NADH electrooxidation was observed using CS coatings, with oxidation starting at ca. -0.10 V (vs. Ag/AgCl, pH 7.0). The CS-coated glassy carbon electrode (CS/GC) thus allows highly sensitive and direct amperometric detection of NADH at lower potential, ranging from 0.20 to 100 mu M with a high sensitivity of 7.3 +/- 0.2 nA mu M-1 (i.e., 103.3 +/- 2.8 nA mu M-1 cm(-2)), low detection limit of 0.08 +/- 0.03 mu M, and minimization of surface fouling. With lactate dehydrogenase (LDH) as a model, a lactate biosensor with the LDH-CS/GC electrode was constructed and the biosensor shows rapid and highly sensitive amperometric response to lactate ranging from 0.5 to 12 mM with a detection limit of 3.7 +/- 0.2 mu M, a sensitivity of 4.1 +/- 0.2 nA mu M-1 (i.e., 57.9 +/- 2.8 nA mu M-1 cm(-2)), good reproducibility and excellent stability. Furthermore, the promoted direct electron transfer (DET) of bilirubin oxidase (BOD) on CS/GC electrode was investigated, and thus a membrane-less lactate/oxygen biofuel cell was assembled by using LDH-CS/GC as bioanode for lactate oxidation and BOD-CS/GC electrode for oxygen reduction, with a high open-circuit potential of 0.60 V. Such ability of CS to decrease the NADH oxidation overpotential and promote DET of blue-copper oxidases suggests great promise for dehydrogenase-based amperometric biosensors and biofuel cells.