Polydopamine nanoparticles@MoS2 nanosheet aerogel-based ECL sensing system for MiRNA-126 detection

Abstract

In this paper, we developed a novel electrochemiluminescence (ECL) sensing system based on polydopamine nanoparticles (PDA NPs) and MoS2 nanosheet aerogel. PDA NPs with phenylboronic acid (PBA) were synthesized as a novel kind of organic nano-luminophores. The PDA-PBA NPs had high ECL efficiency and regulable emitting wavelength (552 ~ 610 nm). MoS2 nanosheet aerogel played the important role in the improvement of ECL sensing performance. On the one hand, MoS2 nanosheet aerogel can load a large number of PDA-PBA NPs. The accommodation of PDA-PBA NPs in the MoS2 nanosheet aerogel kept the dispersed state, which prevented NPs aggregation and ECL quenching effect. On the other hand, the excellent conductivity of MoS2 nanosheet aerogel significantly facilitated the electron transfer. Electron injection with MoS2 nanosheet aerogel can effectively reduce the damage of PDA-PBA NPs by excessive hot electrons. As a result, the ECL signal of PDA-PBA NPs@MoS2 nanosheet aerogel have been amplified over 60 times than PDA NPs. Furthermore, the bright ECL light of PDA-PBA NPs@MoS2 nanosheet aerogel can be clearly observed with the smartphone. Finally, a target-catalyzed hairpin assembly (CHA) sensing mode was designed to visually detect MiRNA-126 (detection limit as 0.56 aM). The MoS2 nanosheet aerogel-based sensing system provided a new pathway in the development of ECL analysis research.