A novel high efficient electrochemiluminescence sensor based on reductive Cu(I) particles catalyzed Zn-doped MoS₂ QDs...

In this work, we explored a high efficient electrochemiluminescence (ECL) sensor based on the synergistic enhancement strategy of Zn-doped MoS₂ quantum dots (QDs) and reductive Cu(I) particles. On the one hand, Zn-doped MoS₂ QDs with sulfur vacancies were designed to improve the ECL activity of QDs. The regulated sulfur vacancies with zinc doping resulted in adsorption and coordination with transition metals of H₂O₂ as coreactant. On the other hand, reductive Cu(I) particles were prepared to further catalyze the coreactant in the ECL system. The tight combination of glutathione (GSH) and copper in reductive Cu(I) particles can perfectly stabilize Cu(I) with outstanding catalytic activity in neutral pH condition. Under reduction of the cathode, the reductive Cu(I) particles acted as the catalytic role continuously. As a result, more ·OH were generated from H₂O₂. The signal of Zn-doped MoS₂ QDs had 4.5-fold enhancement with the assistance of reductive Cu(I) particles. Furthermore, the DNA walker cycle was designed in presence of T7 exonuclease for HPV 16 DNA detection. The biosensor realized sensitive determination of HPV 16 DNA from 0.1 nmol L^-1 to 200 nmol L^-1 with the LOD of 0.03 nmol L^-1. Interestingly, the entire sensing system can be reproduced on a simple family-friendly device powered by batteries. The ECL signal captured by a smartphone can be processed into high-resolution imaging by self-developed software, which provides great possibility of point-of-care HPV 16 DNA determination in the future.