Photoelectrochemical immunoassay of cancer biomarker HE4 on disposable electrodes modified with MPA-stabilized CdTe quantum dots

Early detection and continuous monitoring of cancer biomarkers can significantly enhance the survival rates of the sufferers. As such, the development of sensitive, portable and easy-to-use devices for detecting and monitoring these biomarkers is necessary for early diagnosis and better clinical outcomes. In this work, we constructed and investigated a photoelectrochemical (PEC) device for the detection of human epididymis protein 4 (HE4), a common biomarker of epithelial ovarian cancer. The HE4 antibody was immobilised a screen-printed electrode which had been modified with CdTe quantum dots (CdTe QDs). The immobilization platform exhibited excellent photoelectrochemical properties for the selective and sensitive determination of the target biomolecule. The PEC immunosensing was performed using differential pulse voltammetry and visible light source under optimized conditions, detecting concentrations from 1 to 0.00001 nmol mL−1, with low detection limit of 0.000008 nmol mL−1. The immunosensor showed excellent reproducibility, repeatability, stability and selectivity, with a good recovery in a serum matrix.