【摘要】 报道了一种半微分循环伏安型生物传感器,可同时完成对细胞的识别和计数.该传感器由一个平面热解石墨电极、铂电极及Ag/AgCl电极的三电极系统组成.将阻留微生物细胞的滤膜紧附在工作电极表面,然后在工作电极与对极间施加一扫描电压,进行半微分循环伏安扫描,记录伏安图谱.依据峰电位识别微生物,峰电流的半微分值计数微生物.本研究对三种微生物啤酒酵母菌、大肠杆菌和枯草芽孢杆菌进行了识别,并对其中之一加以计数.它们的峰电位分别是0.75,0.85和0.69V(vs.Ag/AgCl电极),峰电位的重现性良好,CV<5%.还探讨了啤酒酵母浓度与峰电流的关系,发现膜上细胞数在(0.5~2.5)×10~7cells范围内与峰电流呈线性关系,相关系数为0.9901,直线回归方程为Y=0.66+0.56X(×10~7).更多还原

【Abstract】 Detection and classificationn of microbial cell are important in clinical, envi-ronmental and bioindustrial fields. An electrochemical method for detection and classifi-cation of microbial cewlls has been developed by applying semi-differential cyclic voltam-metry to microbial cells. A modified basal plane pyrolytic graphite e1ectrode was em-ployed as a working electrode. Apply a sweep voltage between a working electrode and acounter electrode while the microbial cells on a membrane filter are brought into contactwith the working electrode. Then measure the generated current between the electrodesin phosphate buffered soline. The indexes of discrimination of microbial cells includesthe Ep(the anodic peak potential), the ep(the semidifferential anodic peak current). andthe cathodic peak in inverse voltage-scan.The anodic peak potentials of S. cerevisiae, B. subtilis and E. coli are 0. 75 V,0. 69 V, 0. 85 V(vs Ag/AgCl electrode) respectively. Therefore, these bacteria can beclearly distinguished from each other. The realationship between the peak current andthe cellconcentration of S. cerevisiae was studied. The anodic peak current was propor-tional to the cell numbers on the membrane filter in a range of (0. 5~2. 5) × 107 cells.Regression equation Y=0. 66+0. 56N(×l07), correlation coeffient 0.9901. The mini-mum detectable cell number was 2. 8 × 106 cells. The effects of modifiers was also de-scribed in this paper.更多还原