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

• It developed a low-toxic photoelectric active interface for bioassays.
• Energy levels of QDs were studied explain their PEC performances
• The prepared Ag2S QDs have been used for the detection of glucose and cancer cell.

A new photoelectrochemical (PEC) biosensor was developed using low-toxic Ag2S QDs as photoelectrochemically active species. Energy levels of Ag2S and Ag2Se QD were compared to explain their differences in the PEC performance. The preparation condition of Ag2S 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 Ag2S QD could serve as an excellent and promising photoelectric active material in the PEC biosensor.