Ultrasensitive photoelectrochemical sensing platform for detection of neuron specific enolase based on inhibition effect of CoSnO3 nanobox toward SnO2/Mn0.05Cd0.95S composites

Herein, a novel photoelectrochemical (PEC) immunoassay was developed to detect Neuron specific enolase (NSE) based on the inhibition effect of CoSnO 3 nanobox toward Mn 0.05 Cd 0.95 S sensitized stannic oxide (SnO 2 ). Specifically, the SnO 2 /Mn 0.05 Cd 0.95 S composites with excellent photoelectric properties were employed as substrate materials, which could partially absorb visible-light and effectively inhibit the electron-hole recombination owing to the effect of heterostructure, therefore providing significantly enhanced and stable basal signal. Then, the CoSnO 3 nanobox with excellent steric hindrance effect, uniform size and easy modification was used as labeled secondary antibody, which could obstruct the electrons transfer and further facilitate the decrease of photocurrent intensity to achieve the amplification of signal change value. The high sensitivity and good stability of the immunoassay derived from the enhancement of the original signal and the amplification of signal changes. Accordingly, the as-fabricated PEC immunosensor responded sensitively to NSE with a low detection limit of 0.15 pg mL −1 and a wide linear range from 0.50 pg mL −1 to 100 ng mL −1 . Moreover, the immunosensor also presented good stability, excellent specificity and satisfactory reproducibility, which can provide a potential analytical strategy for NSE and other biomolecules, and provided guidance for the early diagnosis and clinical analysis of small-cell lung cancer (SCLC). • A PEC sensor was developed based on inhibition of CoSnO 3 toward SnO 2 /Mn 0.05 Cd 0.95 S. • Double signal change amplification strategy was employed to increase sensitivity. • The PEC immunosensor was fabricated for ultrasensitive detection of NSE.