Carbon screen-printed electrodes on ceramic substrates for label-free molecular detection of antibiotic resistance

The growing threat posed by antimicrobial resistance on the healthcare and economic well-being of mankind is pushing the need to develop novel and improved diagnostic platforms for its rapid detection at point of care, facilitating better patient management strategies during antibiotic therapy. In this paper, we present the manufacturing and characterisation of a low-cost carbon screen-printed electrochemical sensor on a ceramic substrate. Using label-free electrochemical impedance spectroscopy, the sensor is demonstrated for the detection of blaNDM, which is one of the main antimicrobial resistance factors in carbapenem-resistant Enterobacteriaceae. The electrochemical performance of the newly fabricated sensor was initially investigated in relation to the function of its underlying composite materials, evaluating the choice of carbon and dielectric pastes by characterising properties like surface roughness, wetting and susceptibility of unspecific DNA binding. Subsequently, the sensor was used in an electrochemical impedance spectroscopy assay for the sensitive and specific detection of synthetic blaNDM targets achieving a detection limit of 200 nM. The sensor properties and performance demonstrated in this study proved the suitability of the new electrode materials and manufacturing for further point-of-care test development as an inexpensive and effective alternative to gold electrodes sensor.