New Article Published in Biosensors and Bioelectronics

Whole cell based microcontact imprinted capacitive biosensor for the detection of Escherichia coli

In this study, a label-free, selective and sensitive microcontact imprinted capacitive biosensor was developed for the detection of Escherichia coli. The recognition of E. coli was successfully performed by this sensor prepared with the combination of microcontact imprinting method and capacitive biosensor technology. After prepara- tion of bacterial stamps, microcontact-E. coli imprinted gold electrodes were generated using an amino acid based recognition element, N-methacryloyl-L-histidine methylester (MAH), 2-Hydroxyethyl methacrylate (HEMA) as monomers and ethyleneglycol dimethacrylate (EGDMA) as crosslinker under UV-polymerization. Real-time E. coli detection experiments were carried out within the range of 1.0×102–1.0×107 CFU/mL. The unique combination of these two techniques provides selective detection with a detection limit of 70 CFU/mL. The designed capacitive sensor has high selectivity and was able to distinguish E. coli when present together with competing bacterial strains which are known to have similar shape. In addition, the prepared sensor has the ability to detect E. coli with a recovery of 81–97% in e.g. river water.