Towards Electrochemical Sensor Based on Molecularly Imprinted Polypyrrole for the Detection of Bacteria-Listeria monocytogenes

Detecting bacteria-Listeria monocytogenes-is an essential healthcare and food industry issue. The objective of the current study was to apply platinum (Pt) and screen-printed carbon (SPCE) electrodes modified by molecularly imprinted polymer (MIP) in the design of an electrochemical sensor for the detection of Listeria monocytogenes. A sequence of potential pulses was used to perform the electrochemical deposition of the non-imprinted polypyrrole (NIP-Ppy) layer and Listeria monocytogenes-imprinted polypyrrole (MIP-Ppy) layer over SPCE and Pt electrodes. The bacteria were removed by incubating Ppy-modified electrodes in different extraction solutions (sulphuric acid, acetic acid, L-lysine, and trypsin) to determine the most efficient solution for extraction and to obtain a more sensitive and repeatable design of the sensor. The performance of MIP-Ppy- and NIP-Ppy-modified electrodes was evaluated by pulsed amperometric detection (PAD). According to the results of this research, it can be assumed that the most effective MIP-Ppy/SPCE sensor can be designed by removing bacteria with the proteolytic enzyme trypsin. The LOD and LOQ of the MIP-Ppy/SPCE were 70 CFU/mL and 210 CFU/mL, respectively, with a linear range from 300 to 6700 CFU/mL.

Automated summary

This study aimed to design an electrochemical sensor for the detection of Listeria monocytogenes using platinum and screen-printed carbon electrodes modified by molecularly imprinted polymer (MIP). The performance of MIP and non-imprinted polypyrrole (NIP)-modified electrodes was evaluated using pulsed amperometric detection. The results showed that the most effective extraction solution for removing bacteria and achieving a sensitive and repeatable sensor design was the proteolytic enzyme trypsin. The MIP-Ppy/SPCE sensor had a LOD of 70 CFU/mL and a LOQ of 210 CFU/mL, with a linear range from 300 to 6700 CFU/mL.