In situ ligand modulated highly luminescent and stable perovskite quantum dots for fluoride detection

This work presents a new strategy to improve the optical performance of perovskite quantum dots (QDs) and an excellent fluoride ion sensor. Using amino acids like L-alanine or D-alanine ((L/D)Ala) as surface ligands, a series of novel perovskites have been prepared for extremely sensitive and reliable detection of the fluoride ions (F-). Because the (L/D)Ala ligands effectively hinder the non-radiative transitions, the luminescence quantum yield of MAPbBr3 (CH3NH2 =MA) QDs is increased by 89.05%. The high energy of the bond N-H…F for (L/D)Ala QDs makes high selectivity and sensitivity for F-. The sensing capabilities of (L/D)Ala QDs have a linear dynamic range of 0–160 μM and a low detection limit of 3.8 μM with excellent sensitivity and selectivity.