Ag/Au nanoparticles coated graphene electrochemical sensor for ultrasensitive analysis of carcinoembryonic antigen in clinical immunoassay

•A new electrochemical sensor for determination of carcinoembryonic antigen was developed.•The Ag/Au nanoparticles coated on graphene was used as amplifier of signals.•The ultrasensitive method could be successfully applied for biosample analysis.

This study demonstrates a novel approach toward development of advanced immunosensors based on chemically functionalized Ag/Au nanoparticles coated on graphene for the detection of carcinoembryonic antigen (CEA) in clinical immunoassay. Ag/Au nanoparticles were synthesized and then were used as a signal amplifying factor for construction of the “sandwich-type” immunosensor. The Ag/Au nanostructure presents good electrochemical activity in the working potential range, which provides high current response. Under optimal conditions, the proposed method could respond to carcinoembryonic antigen (CEA) with a linear calibration range from 10 to 1.2 × 105 pg mL−1 with a detection limit of 8 pg mL−1. This new biosensor exhibited high sensitivity and selectivity, and was successfully used in determining the CEA which was added in human serum.

Graphical abstractA novel approach toward development of advanced immunosensors based on chemically functionalized Ag/Au nanoparticles coated on graphene was developed for the detection of carcinoembryonic antigen (CEA) in clinical immunoassay.Figure optionsDownload full-size imageDownload as PowerPoint slide