Electrochemiluminescence energy resonance transfer in 2D/2D heterostructured g-CN/MnO for glutathione detection.

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-CN/MnO was developed using g-CN nanosheets (g-CN NSs) as energy donor and MnO nanosheets (MnO NSs) as energy acceptor. In this system, MnO NSs in-situ grew on g-CN NSs to form the 2D/2D heterostructure, greatly shortening the distance of the donor-acceptor pair (g-CN-MnO) 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, MnO significantly quenched the ECL intensity of g-CN owing to ECL-RET in this 2D/2D g-CN/MnO heterostructure (ECL signal "off"). Upon the addition of GSH, MnO was reduced to Mn by GSH and g-CN was released from the heterostructured g-CN/MnO, 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.