A pro-gastrin-releasing peptide imprinted photoelectrochemical sensor based on the growth of gold nanoparticles on a MoS nanosheet surface

Lamellar MoS 2 nanosheets were successfully prepared by hydrothermal synthesis using 1-(3-mercaptopropyl)-3-methyl-imidazolium bromine (MIMBr) ionic liquid as a sulfur source and a morphology control agent, and sodium molybdate as a molybdenum source. Gold nanoparticles were assembled on the surface of MoS 2 nanosheets by the in situ reduction of chloroauric acid at low temperatures to successfully fabricate AuNP/2D-MoS 2 nanocomposites, thus improving photoelectrochemical response. AuNP/2D-MoS 2 nanocomposites were used as photoelectrically active materials modified onto a glassy carbon electrode surface to construct a photoelectrochemical (PEC) sensor. Then, using 1-( N -pyrrolpropyl)-3-methyl-imidazolium bromine (PMIMBr) ionic liquid as a functional monomer and pro-gastrin-releasing peptide (Pro-GRP) as a template, a molecularly imprinted polymerized ionic liquid film was electrochemically deposited on an AuNP/2D-MoS 2 /GCE surface. Upon removing the templates, a molecularly imprinted photoelectrochemical sensor was constructed for the sensing of a tumor marker, pro-gastrin-releasing peptide. Experimental conditions including ascorbic acid concentration, polymerization conditions, incubation time, and pH value of the incubation solution have been optimized. Under the optimized conditions, the molecularly imprinted photoelectrochemical sensor can specifically detect the target protein Pro-GRP in the range of 0.02 ng mL −1 -5 ng mL −1 with a detection limit of 0.0032 ng mL −1 (S/N = 3). The practicability of this photoelectrochemical sensor was demonstrated by accurately determining Pro-GRP in human serum samples. Molecularly imprinted PEC platform for Pro-GRP sensing was prepared using lamellar MoS 2 nanosheets assembled with gold nanoparticles as photoactive elements. The molecularly imprinted PEC sensor shows excellent sensing performances towards Pro-GRP.