Au@Pt hybrid nanorods encapsulated in B, S dual-doped graphene as highly sensitive immunosensing platform for electrochemical determination of aflatoxin B1

Abstract

A specific electrochemical immunosensor for ultra-sensitive determination of Aflatoxin B1 (AFB1) was developed according to a dual enhancing strategy. The dual-doped graphene (BS-G) was obtianed by a simple microwave-assisted hydrothermal approach, sulfur and boron affinity for peanut-shaped Au@Pt NRs embedded into BS-G nanosheets, ultrathin BS-G effectively enwrapped most of the individual Au@Pt NRs with excellent dispersibility. It is noteworthy that two faces at the interface between (002) crystal faces of BS-G and (111) planes of Au@Pt NRs are compatible, accelerating the charge transfer between the hybrid nanocatalysts and AFB1. Moreover, the highly dispersed COOH groups and defect sites of the BS-G precisely control the orientation of anti-AFB1 immobilized on the sensor surface, meanwhile, the strong electronic interactions endow the Au@Pt NRs/BS-G hybrid nanocatalysts with remarkable biocompatibility and multivalent affinity interactions with the high molar ratio of anti-AFB1 for enhanced immunoreactions. Thus, the designed immunosensor exhibits ultra-efficient electron-transfer abilities, excellent sensitivity, and favorable selectivity, the detection limit is 0.0052 ng·mL-1 and the linear range is 0.025-60.00 ng·mL-1.