应用电化学测菌法检测牙龈卟啉单胞菌的初步研究

Preliminary study on the detection of Porphyromonas gingivalis using electrochemical method

目的:探讨应用电化学测菌法检测牙龈卟啉单胞菌的可行性。方法:应用电化学阻抗谱方法测量去离子水溶液中特定细菌(牙龈卟啉单胞菌)的电化学阻抗,获得针对特定细菌的敏感阻抗谱,建立特定频率下细菌浓度与系统交流阻抗值之间的函数关系,依据函数关系和测得的电化学阻抗值分析待检样品内特定细菌的浓度。结果:当频率低于104Hz时,系统的交流阻抗值随去离子水溶液中牙龈卟啉单胞菌浓度的增加而减小;当设定频率为1.2 kHz、待测细菌(牙龈卟啉单胞菌)浓度为103～109/mL时,牙龈卟啉单胞菌浓度C的对数与系统阻抗值Z呈良好的线性关系(R2=0.98),logC(细胞数/mL)=-0.007 Z(kΩ)+10.792;单一浓度检测用时约40 m in。结论:基于电化学阻抗原理的电化学测菌法有可能成为简便、快速检测牙周致病菌的新方法。

AIM：To investigate the feasibility of using electrochemical method based on impedance measurement to detect Porphyromonas gingivalis.METHODS：Electrochemical impedance spectroscopy of Porphyromonas gingivalis suspension in deinonized（DI） water was measured to find the functional relationship between the logarithmic value of the cell concentration and the impedance magnitude.RESULTS：The impedance spectra of-Porphyromonas gingivalis-suspensions in DI water responded significantly different with cell concentrations when the frequency was below 104Hz.With increasing cell concentrations,impedance magnitude decreased consistently.In the concentration range of 103 to 109 cells/mL,a linear relationship was found between the impedance magnitude and the logarithmic value of the cell concentration with the frequency at 1.2 kHz,which could be described in the equation logC（cells/mL） =-0.007 Z（kΩ） ＋10.792 with R2 = 0.98.The detection time was about 40 minutes.CONCLUSION：The electrochemical method based on impedance measurement might be a simple and rapid novel method to detect periodontal pathogenic bacteria.