摘要： Detection of pathogenic bacteria in dairy farms and processing plants is important for milk quality control. In this study, a simple in situ method for determining the bacterial concentration in milk was developed with an interdigitated microelectrode sensor. This method was based on a punctual measurement of the electrode–milk interface impedance change due to bacterial metabolism in the milk. The interface impedance varied predominately at low frequencies, attributed to the change on the double-layer capacitance. The detection time TD, defined as the time required to attain a −10% impedance change at 10Hz, became a practicable means for the estimation of initial E. coli concentration in milk samples. Regression analysis resulted in a third-order polynomial relationship between the detection time and the logarithm of the initial E. coli concentration (N0, cells/ml) in a milk sample, i.e., log N0=11.48–2.33 TD+0.288(TD)2–0.0154(TD)3 with R2=0.9988. The sensor was able to detect E. coli in milk of initial concentrations as low as 7cells/ml. The proposed impedance sensor is suitable for determining bacterial contamination at dairy farms and processing plants. 出版者： Elsevier Ltd 出版日期： 2015-11-10 出處： Electrochimica acta, 2015-11, Vol.182, p.89-95 版權： 2015 Elsevier Ltd 識別號： ISSN: 0013-4686 識別號： EISSN: 1873-3859 識別號： DOI: 10.1016/j.electacta.2015.09.029
