Muhammet Sinan M, Cete Servet, Arslan Fatma, Yaşar Ahmet
Technical Vocational School of Higher Education, Gazi University, Ankara, Turkey.
Artif Cells Blood Substit Immobil Biotechnol. 2009;37(6):273-8. doi: 10.3109/10731190903356453.
A new amperometric cholesterol biosensor was prepared by immobilizing cholesterol oxidase by a glutaraldehyde crosslinking procedure on polypyrrole-polyaniline (ppy-pani) composite film on the surface of a platinum electrode. In order to prepare a biosensor for the determination of cholesterol, electropolymerization of pyrrole and aniline on Pt surface was performed with an electrochemical cell containing pyrrole and aniline in sulphuric acid by cyclic voltammetry between 0.0 and 0,7 V (vs.Ag/AgCl) at a scan rate of 50 mV upon Pt electrode. The amperometric determination is based on the electrochemical detection of H(2)O(2), which is generated in enzymatic reaction of cholesterol. The cholesterol determined by the oxidation of enzymatically generated H(2)O(2) at 0.7 V vs. Ag/AgCl. The optimized cholesterol oxidase biosensor displayed linear working range and a response time of 300 s. The effects of pH and temperature were investigated and optimum parameters were found to be 7.0, 25 degrees C, respectively. In addition to this, the stability and reproducibility of biosensor were tried. Operational stability of the proposed cholesterol biosensor was obtained by periodical measurements of the biosensor response. Biosensor at optimum activity conditions was used in 30 activity assays in one day to determine the operational stability. The results show that 82% of the response current was retained after 30 activity assays. The electrode was stored in a refrigerator at 4 degrees C after the measurements. The storage stability of the biosensor was determined by performing activity assays within 23 days. The results demonstrate that 60% of the response current was retained after 23 days. Preparing biosensor is used for the analysis of cholesterol in serum.
通过戊二醛交联法将胆固醇氧化酶固定在铂电极表面的聚吡咯 - 聚苯胺（ppy - pani）复合膜上，制备了一种新型的电流型胆固醇生物传感器。为了制备用于测定胆固醇的生物传感器，在含有吡咯和苯胺的硫酸电化学池中，通过循环伏安法在铂电极上以50 mV的扫描速率在0.0至0.7 V（相对于Ag/AgCl）之间对吡咯和苯胺进行电聚合。电流测定基于对胆固醇酶促反应中产生的H₂O₂的电化学检测。在相对于Ag/AgCl为0.7 V的电压下，通过酶促产生的H₂O₂的氧化来测定胆固醇。优化后的胆固醇氧化酶生物传感器显示出线性工作范围和300 s的响应时间。研究了pH值和温度的影响，发现最佳参数分别为7.0和25℃。除此之外，还对生物传感器的稳定性和重现性进行了测试。通过定期测量生物传感器的响应来获得所提出的胆固醇生物传感器的操作稳定性。在最佳活性条件下的生物传感器在一天内用于30次活性测定以确定操作稳定性。结果表明，经过30次活性测定后，响应电流保留了82%。测量后，电极保存在4℃的冰箱中。通过在23天内进行活性测定来确定生物传感器的储存稳定性。结果表明，23天后响应电流保留了60%。所制备的生物传感器用于血清中胆固醇的分析。
