Treated Gold Screen-Printed Electrode as Disposable Platform for Label-Free Immunosensing of Salmonella Typhimurium.

Label-free detection is a fashion manner to accomplish analysis in immunosensing field, owing to the possibility to avoid labelled antibody and enzymatic reaction time, as well. To develop a label-free immunosensor, the electrochemical impedance spectroscopy in combination with the bulk gold electrode is one of the most common approaches; however, the use of laboratory setup as well as the cost of gold bulk electrode hinders their widespread applications. Herein, we report a label-free impedimetric immunosensor based on the use of gold screen-printed electrodes for Salmonella Typhimurium, chosen as model analyte. With the aim to enhance the immunosensor electrochemical performances, different protocols were accomplished to pre-treat the working electrode surface used as platform to immobilise the immunological chain in a self-assembled monolayer configuration. Salmonella Typhimurium was detected with a linear range comprised between 103 and 107 CFU/mL, demonstrating the suitability of the treated gold-printed electrode combined with portable instrumentation as implemented electrochemical analytical tool for effective and in situ analysis.