Effective signal-on photoelectrochemical immunoassay of subgroup J avian leukosis virus based on Bi2S3 nanorods as photosensitizer and in situ generated ascorbic acid for electron donating.

A universal and effective photoelectrochemical (PEC) immunosensing device was fabricated on an indium tin oxide (ITO) electrode for sensitive and specific detection of subgroup J of avian leukosis virus (ALVs-J) based on a signal-on strategy. Bismuth sulfide (Bi2S3) nanorods, with good morphology, high crystallinity and differentiated PEC properties, were selected as the photoelectrochemical species and synthesized by a facile hydrothermal method. On the basis of alkaline phosphatase catalytic chemistry to in situ produce ascorbic acid for electron donating, an enhanced photocurrent was obtained. Due to the dependence of the photocurrent signal on the concentration of generated electron donor, an exquisite immunosandwich protocol was successfully constructed for PEC detection of ALVs-J with a linear range from 10(2.14) to 10(3.65) TCID50/mL. The detection limit was 10(2.08) TCID50/mL (S/N=3), and high stability and specificity were obtained. The strategy provides a fast and sensitive method for ALVs-J analysis and opens a general format for future development of PEC immunoanalysis.