Highly Efficient Electrochemiluminescence Based on Luminol/MoS<sub>2</sub> Quantum Dots@Zeolitic Imidazolate Framework-8 as an Emitter for Ultrasensitive Detection of MicroRNA
Wei Liu, Meiling Su, Anyi Chen, Kanfu Peng, Yaqin Chai, Ruo Yuan
Abstract
Herein, a highly efficient electrochemiluminescence (ECL) emitter, luminol/MoS2 quantum dots@zeolitic imidazolate framework-8 (Lu/MoS2 QDs@ZIF-8), with a positive charge was prepared to construct a novel luminol–H2O2–MoS2 QD ternary ECL system for ultrasensitive detection of microRNA-21 (miRNA-21). The porous Lu/MoS2 QDs@ZIF-8 was beneficial for reducing the accessible distance between various participants in the ternary system wherein co-reaction accelerator MoS2 QDs promoted H2O2 to generate superoxide anion radicals (O2•–), which instantaneously reacted with luminol to produce robust ECL signals. Simultaneously, the positively charged Lu/MoS2 QDs@ZIF-8 facilitated the enrichment of O2•– to further improve the ECL efficiency of luminol. Impressively, compared with the traditional binary luminol–H2O2 system, the ECL efficiency of this ternary system was increased by 12.7 times. In the aid of a target-cycled and endogenous adenosine triphosphate-driven signal amplification strategy, the biosensor with Lu/MoS2 QDs@ZIF-8 as an ECL emitter achieved ultrasensitive detection for miRNA-21 with a detection limit of 14.6 aM. This work provides a promising perspective to construct a highly efficient ECL ternary system for biomolecule detection and potential disease diagnosis.