Silica nanoparticles-assisted electrochemical biosensor for the rapid, sensitive and specific detection of Escherichia coli

To face the emerging issues raised by bacterial infections in biomedical, food and environmental contexts, the combination of nanotechnologies and biosensors characteristics is increasingly seen as a promising tool to develop rapid, highly sensitive and specific devices for reliable bacterial detection and quantification. We present here the design of an electrochemical immuno-biosensor, integrating non cytotoxic silica nanoparticles (NPs), in a two-step spin coating process. Unlike biosensors that integrate a unique antibody-based layer without NPs, this new tool allows, through cyclic voltammetry measurements, the continuous and non-saturated detection of E. coll. bacteria in only 5 min. and can reach up to 10(3) CFU/mL in 30 min. It offers great promises for industrial purposes as electrode functionalization is rather simple and its architecture can be tuned on demand to target a variety of micro-organisms, and the highlighted indicators (variations of current intensity, intensity ratios and/or difference of potentials) can easily be implemented in a screen displayed packaging.