Photoelectrochemical immunoassay platform based on MoS2 nanosheets integrated with gold nanostars for neuron-specific enolase assay.

MoS2 nanosheets were prepared by exfoliating MoS2 bulk crystals with ultrasonication in N-methylpyrrolidone and were integrated with gold nanostars (AuNS) to fabricate an AuNS/MoS2 nanocomposite. All nanomaterials were characterized by transmission electron microscope, scanning electron microscope, ultraviolet-visible spectroscopy, X-ray diffraction, and X-ray photoelectron spectroscopy. AuNS/MoS2 nanocomposites were coated onto a glassy carbon electrode (GCE) surface to construct a nanointerface for immobilizing neuron-specific enolase antibody (anti-NSE) thus forming a photoelectrochemical immunoassay system. AuNS can significantly promote the photoelectric conversion of MoS2 nanosheets improving the performance for a photoelectrochemical assay. Being illuminated with white light LED and controlling the potential at 0.05 V (vs. SCE), the photocurrent generated from anti-NSE(BSA)/AuNS/MoS2/GCE using 0.15 mol L-1 ascorbic acid as electron donor can be recorded with amperometry and used as an output signal for NSE quantitative assay. Under optimized experimental conditions, the photocurrent variation for the affinity-binding NSE is proportional to the logarithm of NSE concentration in the range 5.0 pg mL-1   to 1.5 ng mL-1 with a detection limit of 3.5 pg mL-1 (S/N = 3). The practicability of the PEC immunoassay system was evaluated by determining NSE in clinical serum samples. The recoveries ranged from 93.0 to 103% for the determination of NSE in serum samples with a standard addition method. The PEC immunoassay system possesses good accuracy for determining NSE in real samples. Graphical abstract.

Citation

Renxi Liu, Yanying Wang, Wingleung Wong, Haiyan Li, Chunya Li. Photoelectrochemical immunoassay platform based on MoS2 nanosheets integrated with gold nanostars for neuron-specific enolase assay. Mikrochimica acta. 2020 Aug 02;187(8):480

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PMID: 32743701

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