Electrochemiluminescence energy resonance transfer in 2D/2D heterostructured g-C3N4/MnO2 for glutathione detection

Abstract

The energy transfer efficiency, strongly depending on the distance of donor-acceptor pair, is always a crucial factor for the construction of elegant electrochemiluminescence resonance energy transfer (ECL-RET)-based biosensors. In this paper, a novel and efficient ECL-RET in 2D/2D heterostructured g-C₃N₄/MnO₂ was developed using g-C₃N₄ nanosheets (g-C₃N₄ NSs) as energy donor and MnO₂ nanosheets (MnO₂ NSs) as energy acceptor. In this system, MnO₂ NSs in-situ grew on g-C₃N₄ NSs to form the 2D/2D heterostructure, greatly shortening the distance of the donor-acceptor pair (g-C₃N₄-MnO₂) and thus greatly enhancing the RET efficiency. To demonstrate the performance of the system, a signal "off-on" ECL sensor was designed for glutathione (GSH) analysis. In the absence of GSH, MnO₂ significantly quenched the ECL intensity of g-C₃N₄ owing to ECL-RET in this 2D/2D g-C₃N₄/MnO₂ heterostructure (ECL signal "off"). Upon the addition of GSH, MnO₂ was reduced to Mn²⁺ by GSH and g-C₃N₄ was released from the heterostructured g-C₃N₄/MnO₂, generating a recovery of ECL intensity (ECL signal "on"). Under the optimal conditions, the designed ECL-RET signal "off-on" sensor realized the sensitive detection of GSH ranged from 0.2-100 μM with the detection limit of 0.05 μM. Furthermore, the as-prepared ECL-RET sensor exhibits good performance in the determination of GSH in human serum samples. The ECL-RET in 2D/2D heterostructure provides an ingenious way for the exploitation of novel ECL biosensing systems.

Keywords: 2D/2D heterostructured g-C(3)N(4)/MnO(2); Electrochemiluminescence resonance energy transfer; Glutathione.