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

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 x 10(5) 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. (C) 2014 Elsevier B.V. All rights reserved.