Co9S8 nanoparticle-functionalized CdS nanoflowers for signal-off photoelectrochemical bioanalysis of carcinoembryonic antigens with hybridization chain reaction

(A) Schematic diagram of Co 9 S 8 nanoparticle-decorated CdS nanoflowers-based photoelectrochemical (PEC) aptasensor for the detection of carcinoembryonic antigen (CEA); and (B) the photocurrent response mechanism of PEC bioanalysis.