Molecularly imprinted conducting polymer based sensor for Salmonella typhimurium detection

Abstract

This manuscript reports the design and fabrication of conducting plastibody based electrochemical sensor for the detection of Salmonella typhimurium. The conductive plastibody was fabricated on an Indium Tin Oxide surface through potentiostatic method (electrodeposition for 400 s), wherein a polymer mix of pyrrole, lactic acid, ammonium chloride, and sodium dodecyl sulfate was employed for the electrodeposition. Various template removal methods were tested and electrochemical cleaning in the MES buffer was found to be the most suitable, which was optimized further. The synthesized plastibody sensors were characterized using electrochemical impedance spectroscopy, contact angle, FTIR spectroscopy and scanning electron microscopy. Amperometry was used as the electrochemical analytical technique for the determination of the analyte in the concentration range of 100 –108 CFU/mL having a limit of detection of 3.42 CFU/mL. Sensor’s performance was also compared with the non-imprinted electrode and an imprinting factor of 3.8 was found. The plastibody sensor was tested against other bacteria and coefficient of selectivity was calculated to be 1.0, 10.8, 5.6 and 2.4 towards S. typhi, S. aureus, E. coli and L. monocytogenes respectively. The sensor was also found to be reproducible in nature (RSD 0.11 %) and this generic concept presented herein may be extended for the detection of pathogens in other matrices as well.