Low-toxic Ag2S quantum dots for photoelectrochemical detection glucose and cancer cells

A new photoelectrochemical (PEC) biosensor was developed using low-toxic Ag 2 S QDs as photoelectrochemically active species. Energy levels of Ag 2 S and Ag 2 Se QD were compared to explain their differences in the PEC performance. The preparation condition of Ag 2 S QD was optimized and its structure characterization was measured. Then the developed photoelectric active interface was used to detect glucose and MCF-7 cancer cell and showed the good sensitivity and specificity. Under optimal condition, detection limits of 3.2×10 −5   M for glucose and 98   cells/mL for MCF-7 cell were achieved. Thus, the prepared Ag 2 S QD could serve as an excellent and promising photoelectric active material in the PEC biosensor.