Photoelectrochemical immunosensor for HER2 detection based on BiVO4-Bi2S3 heterojunction as photoactive material and CdS as signal probe

A sandwiched photoelectrochemical (PEC) sensor was developed for sensitive detection of human epidermal growth factor receptor 2 (HER2) based on BiVO4-Bi2S3 heterojunction as the photoelectric material accompanied with magnetic nanoparticles for enrichment of HER2 and CdS for signal amplification. The in situ generation of Bi2S3 on the surface of BiVO4 forming a BiVO4-Bi2S3 heterojunction is more conducive to the transit of electron-hole pairs. Antibody-modified MNs are utilized to capture and separate HER2 from samples. After forming a sandwich immune structure, under illumination, the photocurrent shows an increasing trend with the increment of HER2 concentration. The PEC immunosensor displays a good linear concentration range between 1.00 and 1.00 x 10(3) pg center dot mL(-1) and a low limit of detection down to 0.680 pg center dot mL(-1) (S/N = 3) for HER2 under a bias voltage of 0.1 V (vs. Ag/AgCl electrode). Furthermore, the sensor was successfully applied to detect HER2 in serum samples with recoveries that ranged between 96.1 and 114% with RSDs between 1.3 and 5.9%.

Automated summary

A sandwiched photoelectrochemical (PEC) sensor was developed for sensitive detection of human epidermal growth factor receptor 2 (HER2) using BiVO4-Bi2S3 heterojunction as the photoelectric material, magnetic nanoparticles for HER2 enrichment, and CdS for signal amplification. The formation of BiVO4-Bi2S3 heterojunction facilitated the transit of electron-hole pairs. Antibody-modified magnetic nanoparticles were used to capture and separate HER2, and under illumination, the photocurrent increased with HER2 concentration. The PEC immunosensor exhibited a linear concentration range of 1.00-1.00 x 10(3) pg center dot mL(-1) and a low limit of detection of 0.680 pg center dot mL(-1) (S/N = 3) for HER2 at a bias voltage of 0.1 V (vs. Ag/AgCl electrode). The sensor was successfully applied to detect HER2 in serum samples with recoveries between 96.1% and 114% and RSDs between 1.3% and 5.9%.