Fabrication of Pt/Cu3(PO4)2 ultrathin nanosheet heterostructure for photoelectrochemical microRNA sensing using novel G-wire-enhanced strategy

Abstract

Herein, we focus on preparing a highly efficient photocatalytic material to construct a signal-on photoelectrochemical (PEC) sensing platform in view of the rigorous demand of accurate miRNA quantification. The well-dispersed Pt nanoclusters-coated copper phosphate ultrathin nanosheets (PtNCs/Cu₃(PO₄)₂NSs) were first successfully synthesized as a photoelectrode material. Because of the ultrathin two-dimensional lamellar structure of Cu₃(PO₄)₂NSs with a 1.3 nm thickness, as well as the homogeneous size and abundant PtNCs loaded on Cu₃(PO₄)₂NSs, the resultant PtNCs/Cu₃(PO₄)₂NSs were employed as a photoelectrode material for the first time and revealed outstanding photocatalytic activity in PEC sensing as a substrate. As a well-designed protocol, we realized accurate miRNA quantification via a novel signal amplification strategy based on G-wire superstructure exponentially ligating a signal probe, which possesses efficient and simple operation compared to the traditional amplification method. Moreover, the electron donor is generated in situ by lactate oxidase (Lox) labels catalyzing lactate for H₂O₂ production, boosting the efficient separation of electron–hole pairs for further signal amplification. Impressively, this PEC sensing platform is commendably utilized to determine miRNA-141 from prostate carcinoma cell line 22Rv1. This study, considering the excellent PtNCs/Cu₃(PO₄)₂NSs combined with G-wire superstructure for exponential signal amplification strategy, paves a new path in biosensing and clinical diagnosis.