Biofunctionalization process of a-SiC:H surfaces applied to an interdigitated microelectrode array to detect enterotoxigenic Escherichia coli

Abstract

A biofunctionalization process of a-SiC:H surfaces has been applied to an interdigitated microelectrode array (IMA) whose microelectrodes are covered by this material. The biofunctionalization process has been monitored stage by stage using Fourier transform infrared spectroscopy (FTIR), while its effects on the electrical behavior of the IMA were recorded in electrical impedance spectra. The process involves hydroxylation, silanization, generation of aldehyde groups, binding via protein A, immobilization of anti-Escherichia coli polyclonal antibodies, entrapping and detection of enterotoxigenic Escherichia coli (ETEC) in Luria-Bertani medium. The FTIR spectra confirm the success of the process. Regarding the performance of the IMA, although the detection of ETEC is successful and its percentage change in impedance reaches a value of 133.37% to 107 CFU/mL, some considerations may be taken into account to improve the sensitivity of the IMA by mean of the optimization of both the IMA design and the biofunctionalization process.