Visible LED light driven photoelectroanalytical detection of antibodies of visceral leishmaniasis based on electrodeposited CdS film sensitized with Au nanoparticles

This work describes the development of a high sensitive photoelectrochemical immunosensor for the detection of anti-Leishmania infantum antibodies. The proposed sensor is based on cadmium sulfide films and gold nanoparticles deposited on indium tin oxide coated glass slide (AuNP/CdS/ITO). The band gap and flat band characteristics of AuNP/CdS platform were evaluated by UV-vis spectrophotometry and electrochemical impedance spectroscopy. The effects of the nature, concentration, and pH of the buffer solution as well as the effects of the applied potential on the response of the photoelectrochemical platform to a donor molecule were investigated. Under optimized conditions, the AuNP/CdS/ITO platform modified with recombinant L. infantum antigens (C8/MPA-AuNP/CdS/ITO) shows a linear response range from 1 up to 300 nmol L−1 to anti-C8 antibodies. Finally, the capability of the proposed photoelectrochemical immunosensor to discriminate positive and negative canine serum samples was evaluated.