Department of Chemistry, Indian Institute of Technology Roorkee, Roorkee 247667, Uttranchal, India.
Talanta. 2010 Nov 15;83(1):149-55. doi: 10.1016/j.talanta.2010.08.054. Epub 2010 Sep 25.
Electrochemical sensor employing edge-plane pyrolytic graphite electrode (EPPGE) for the sensitive detection of hydrocortisone (HC) is delineated for the first time. The electrochemical properties are investigated exercising the cyclic voltammetry and square-wave voltammetry (SWV). When equating with the bare basal-plane pyrolytic graphite electrode (BPPGE), the EPPGE gave better response towards the detection of HC both in terms of sensitivity and detection limit. The voltammetric results indicated that EPPGE remarkably enhances the reduction of HC which leads to considerable amelioration of peak current with shift of peak potential to less negative values. The difference in the surface morphology of two electrodes has been studied. Also, the EPPGE delivered an analytical performance for HC with a sensitivity of 45 nA nM(-1) and limit of detection of 88 nM in the concentration range 100-2000 nM. The method has been utilized for the determination of HC in pharmaceuticals and real samples. The electroanalytical method using EPPGE is the most sensitive method for determination of HC with lowest limit of detection to date. The major metabolites present in blood plasma did not intervene with the present investigation as they did not exhibit reduction peak in the experimental range used. A comparison of results with high performance liquid chromatography (HPLC) signalizes a good agreement.
首次描述了一种采用边缘平面热解石墨电极（EPPGE）的电化学传感器，用于灵敏检测氢化可的松（HC）。通过循环伏安法和方波伏安法（SWV）研究了电化学性质。与裸基面热解石墨电极（BPPGE）相比，EPPGE 在检测 HC 时的灵敏度和检测限都有更好的响应。伏安法结果表明，EPPGE 显著增强了 HC 的还原，导致峰电流显著增加，峰电位向更负的方向移动。研究了两种电极的表面形貌差异。此外，EPPGE 对 HC 的分析性能在 100-2000 nM 的浓度范围内具有 45 nA nM(-1)的灵敏度和 88 nM 的检测限。该方法已用于药物和实际样品中 HC 的测定。使用 EPPGE 的电化学分析方法是迄今为止检测 HC 最灵敏的方法，检测限最低。由于在实验范围内没有出现还原峰，血浆中存在的主要代谢物没有干扰本研究。与高效液相色谱（HPLC）的结果比较表明，两者具有良好的一致性。
