Molecularly imprinted photoelectrochemical sensor for carcinoembryonic antigen based on polymerized ionic liquid hydrogel and hollow gold nanoballs/MoSe2 nanosheets

Highlights: • Hollow gold nanoballs integrated with MoSe₂ nanosheets was used for photoelectrochemical sensing. • Polymerized ionic liquid hydrogel was prepared using BCCPEimBr as functional monomer. • Molecularly imprinted photoelectrochemical sensing platform was developed for carcinoembryonic antigen. • Excellent sensing performances of the imprinted sensor towards CEA were demonstrated. -- Abstract: Using carcinoembryonic antigen (CEA) imprinted polymerized ionic liquid hydrogel as a recognition element and hollow gold nanoballs/MoSe₂ nanosheets as a photoactive element, a photoelectrochemical (PEC) sensing platform was successfully fabricated. To accomplish the imprinted process under room temperature to maintain the biological activity and the configuration of CEA, and thus to improve the sensing performances, 3-{[{4-N,N-Bis[(carbamoyl)ethylmethacrylate]butyl}((carbamoyl)amino)ethyl methacrylate] -propyl}-1-ethenyl-1H-imidazol-3-ium bromide (BCCPEimBr) ionic liquid was synthesized. By using BCCPEimBr ionic liquid as the functional monomer, CEA as the template, a molecularly imprinted hydrogel film was prepared on a hollow gold nanoballs/MoSe₂ nanosheets modified glassy carbon electrode surface. After removing the template, a CEA imprinted photoelectrochemical sensor was successfully fabricated. The imprinted PEC sensor shows good selectivity, sensitivity and stability towards CEA, produces a linear response in the concentration range from 0.05 to 5.0 ng mL⁻¹ and shows a detection limit of 11.2 pg mL⁻¹ (S/N = 3) under the optimized conditions. The imprinted PEC sensor was used to determine CEA in clinical human serum samples accurately. The procedure for the imprinted PEC sensing platform can be used for other biomolecules just by substituting the template.