Krylov Andrey V, Beissenhirtz Moritz, Adamzig Holger, Scheller Frieder W, Lisdat Fred
Analytical Biochemistry, Institute of Biochemistry and Biology, Bldg. 25, University of Potsdam, Karl-Liebknecht-Str. 24-25, 14476, Golm, Germany.
Anal Bioanal Chem. 2004 Mar;378(5):1327-30. doi: 10.1007/s00216-003-2426-8. Epub 2004 Jan 21.
Cytochrome c was immobilized on screen-printed thick-film gold electrodes by a self-assembly approach using mixed monolayers of mercaptoundecanoic acid and mercaptoundecanol. Cyclic voltammetry revealed quasi-reversible electrochemical behavior of the covalently fixed protein with a formal potential of +10 mV vs. Ag/AgCl. Polarized at +150 mV vs. Ag/AgCl the electrode was found to be sensitive to superoxide radicals in the range 300-1200 nmol L(-1). Compared with metal needle electrodes sensitivity and reproducibility could be improved and combined with the easiness of preparation. This allows the fabrication of disposable sensors for nanomolar superoxide concentrations. By changing the electrode potential the sensor can be switched from response to superoxide radicals to hydrogen peroxide-another reactive oxygen species. H(2)O(2) sensitivity can be provided in the range 10-1000 micromol L(-1) which makes the electrode suitable for oxidative stress studies.
通过使用巯基十一烷酸和巯基十一烷醇的混合单分子层的自组装方法，将细胞色素c固定在丝网印刷厚膜金电极上。循环伏安法揭示了共价固定蛋白质的准可逆电化学行为，相对于Ag/AgCl的形式电位为+10 mV。在相对于Ag/AgCl为+150 mV的电位下极化时，发现该电极对300 - 1200 nmol L⁻¹范围内的超氧自由基敏感。与金属针电极相比，其灵敏度和重现性可以得到提高，并且制备简便。这使得能够制造用于纳摩尔级超氧浓度的一次性传感器。通过改变电极电位，该传感器可以从对超氧自由基的响应切换到对另一种活性氧物质过氧化氢的响应。在10 - 1000 μmol L⁻¹范围内可以提供对H₂O₂的灵敏度，这使得该电极适用于氧化应激研究。
