Electric field-driven strategy for multiplexed detection of protein biomarkers using a disposable reagentless...

A fast, simple, sensitive, and low-cost method for electrochemical multianalyte immunoassay was developed by combining newly designed electric field-driven incubation with a screen-printed reagentless immunosensor array. The disposable array was prepared by immobilizing respectively horseradish peroxidase (HRP)-labeled antibodies modified gold nanoparticles in biopolymer/sol-gel modified electrodes to obtain direct electrochemical responses of HRP. Upon the formation of immunocomplexes, the responses decreased due to increasing spatial blocking and impedance. At a driving potential of 0.5 V, the incubation process could be accomplished within 2 min. Under optimal conditions, this method could simultaneously detect carbohydrate antigens 153, 125, and 199 and carcinoembryonic antigens ranging from 0.084 to 16, 0.11 to 13, and 0.16 to 15 U mL(-1) and 0.16 to 9.2 ng mL(-1) with a detection time of less than 5 min, and the detection limits corresponding to the signals of 3SD were 0.06, 0.03, and 0.10 U mL(-1) and 0.04 ng mL(-1), respectively. The disposable immunosensor array and simple detection system for fast measurement of panels of tumor markers show significant clinical value for application in cancer screening and provide great potential for convenient point-of-care testing and commercial application.