Novel Cu nanocluster superlattice/MBene-induced ECL enhancement strategy for miRNA-221 detection

In this paper, copper nanoclusters with superlative structure (Cu NCSL) were developed as luminescence probe for miRNA-221 detection. The tightly aligned superlattice structure of Cu NCSL effectively reduced the disordered and chaotic accumulation of nanoparticles, which further limited the intramolecular vibration and internal rotation of Cu NCs. Meanwhile, the compact particle stacking in the superlattice structure greatly improved the electron transport efficiency. As a result, the luminescence of Cu NCSL was enhanced greatly with the increase of radiation energy transfer rate. Furthermore, the two-dimensional MBene with good electrical conductivity and high electrochemical performance has been prepared as electrode modification material. In the constructed electrochemiluminescence (ECL) sensor for miRNA-221 detection, the ECL signal of Cu NCSL was amplified by the MBene nanosheets effectively. Finally, the results in the actual tumor tissues showed that the Cu NCSL/MBene-based biosensor has high selectivity, stability and low detection limit in the clinical cancer detection.