Confined gold atoms-MXene-based ECL sensing interface for the measurement of myeloperoxidase activity in saliva

In this work, a novel sensing interface has been constructed based on the confined gold atoms-MXene nanosheet. In order to improve the sensing performance of MXene, high photoelectric active confined gold atoms-MXene nanosheet were prepared as electrochemiluminescence (ECL) emitter unit firstly. Based on the electronic metal − support interaction, gold single atoms confined on MXene can provide more active sites and efficient electron transfer to generate strong luminescence signal. Furthermore, in order to improve the biocompatibility, an ECL sensing interface with the Au atoms-MXene nanosheet and chitosan was constructed via the layer-by-layer self-assembly (LBL). Therefore, the proposed sensing interface possessed the large specific surface area, good biocompatibility, high electrocatalytic activity and strong ECL signal. As a potential biomarker, the elevated myeloperoxidase (MPO) concentration and activity were associated with many pathological factors to assess the risk of respiratory diseases. To expand the application of this ECL sensing interface in clinical diagnosis, MPO activity was detected in saliva samples. The satisfactory results indicated the confined gold atoms-MXene-based sensing interface possessed great potential in the ECL research and clinical analysis.