Pushing the Boundaries of Perovskite Based Optical Sensors Novel Design and Synthesis of Stable Perovskite Nanocrystals for High Detection Limits

Abstract

Perovskite quantum dots (PQDs) are promising candidates for fluorescence metal ion sensing due to their outstanding luminescent characteristics. In this study, the role of the inner filter effect (IFE) in PQD-based sensing platforms is highlighted, particularly its contribution to improving detection sensitivity. Two distinct sensing systems exhibiting different degrees of IFE were developed for Co2+ detection: one employing long-chain monodentate ligands on PQDs and the other using short-chain bidentate ligands. The fluorescence quenching mechanism was found to involve both Forster resonance energy transfer (FRET) and IFE. The spatial proximity and electrostatic interaction between the PQDs donor (D) and Co2+ acceptor (A) were suitable for efficient energy transfer, supporting partial FRET. At the same time, a significant spectral overlap between the absorption of Co2+ and the excitation/emission of PQDs resulted in a pronounced IFE. newline