Triple amplified ultrasensitive electrochemical immunosensor for alpha fetoprotein detection based on MoS2@Cu2O-Au nanoparticles

Recently, alpha fetoprotein (AFP), a tumour marker to identify adult primary liver cancer, has attracted increasingly widespread attention. In this work, an ultrasensitive sandwich-type electrochemical biosensor was fabricated for AFP detection. Electrodeposited gold nanoparticles (D-Au NPs) modified on glassy carbon electrodes (GCE) were used as antibody carriers and sensing platforms. Furthermore, a molybdenum disulfide @ cuprous oxide hybrid (MoS2@Cu2O) was prepared to combine gold nanoparticles (Au NPs) as a strategy for achieving signal amplification. The experimental results revealed that molybdenum disulfide @ cuprous oxide-gold nanoparticles (MoS2@Cu2O-Au) showed superb tri-amplification electrochemical signals when catalyzing hydrogen peroxide (H2O2) reduction. This method was demonstrated as a novel tool for the highly reliable separation and quantification of AFP. Under the most suitable experimental conditions, the proposed method exhibits a linear range from 0.1 pg/mL to 50 ng/mL and a low detection limit of 0.037 pg/mL (S/N = 3). The ultrasensitive electrochemical immunosensor has been tested for human serum, and satisfactory recoveries were obtained, indicating that the proposed method is promising for practical applications in the clinical diagnosis of AFP detection.