Microfluidic electrochemical device for real-time culturing and interference-free detection of Escherichia coli

Bacterial contamination and infection is a major health concern today leading to the significance of its detection. Being lab-based bacterial culturing processes, the present approaches are time consuming and require trained skillset. An economical, and miniaturized lab-on-chip device, capable of simultaneous detection of bacterial growth, could be a benchmarking tool for monitoring the bacterial contamination. Herein, the microfluidic-based electrochemical device for a fast, susceptible, detection of Escherichia coli was developed. The device could aid incubator free bacteria culturing in the ambient atmosphere and simultaneously monitor and detect the growth electrochemically. A three-electrode system, integrated with a reservoir and a portable thermostat temperature controller was fabricated and assembled. To achieve this, three-electrodes were embedded on the microfluidic device by screen-printing carbon paste, and the working electrode was enhanced by graphitized mesoporous carbon. Cyclic voltammetry response was noted as the function of concentration and growth of Escherichia Coli in the reservoir. The device gave a linear bacterial concen-tration range of 0.336 x 1012 to 40 x 1012 CFU mL-1, detection limit of 0.35 CFU mL-1 and the quantification limit of 1.05 CFU mL-1 which was less than the maximum allowable limit. The developed platform was further used to detect and continuously monitor the bacterial growth in the real sample (mango juice) for a period of 36 h. Finally, the

Automated summary

A microfluidic-based electrochemical device was developed for fast and sensitive detection of Escherichia coli. The device enables incubator-free bacterial culturing in ambient atmosphere and simultaneous monitoring and detection of bacterial growth using electrochemical methods. The device showed high sensitivity and quantification limit, and was successfully used to monitor bacterial growth in real samples.