Photoelectrochemical immunosensor for carcinoembryonic antigen detection-an attempt for early cancer screening

A photoelectrochemical (PEC) immunosensor based on MIL-101(Cr) and CdTe-QDs composites (M&C) was successfully synthesized to assay the carcinoembryonic antigen (CEA) in human serum and urine samples. This novel method contained three key aspects: 1), the polarity of the photocurrent based on MIL-101(Cr) itself could be altered by applying a different voltage to detect the cathode and anode photocurrent. 2), the introduction of cadmium telluride quantum dots (CdTe-QDs) greatly improved the efficiency of light utilization. 3), the pho-togenerated electron-hole-pairs were suppressed and their separation efficiency was improved by effective matching of energy level between MIL-101(Cr) and CdTe-QDs. Due to the inherent insulating properties of the biological matrix, the transfer of photogenerated electrons was hindered, leading to a decreased photocurrent signal. Under the optimal condition, the anodic and cathodic detection limit of the PEC immunosensor for CEA was 0.00018 ng mL-1 and 0.00023 ng mL-1 , respectively. The linear range was 0.0001-10 ng mL-1. The developed PEC immunosensor showed acceptable stability and sensitivity for the analysis of human serum and urine samples. For future perspective, using PEC and 3D-printing technology, a small PEC detector was designed with the potential to detect tumor markers.

Automated summary

A photoelectrochemical immunosensor based on MIL-101(Cr) and CdTe-QDs composites was synthesized to detect the carcinoembryonic antigen (CEA) in human serum and urine samples. The sensor demonstrated altered photocurrent polarity, improved light utilization efficiency, and enhanced separation efficiency of electron-hole pairs. Under optimized conditions, the sensor showed high sensitivity and stability, with detection limits of 0.00018 ng mL-1 and 0.00023 ng mL-1 for anodic and cathodic detection of CEA, respectively.