A CsPbNiBr NCs-based fluorescence sensor for rapidly and accurately evaluating trace water in edible oils along with the structure destruction and dissolution.

Metal ions with smaller radii than Pb can stabilize CsPbBr NCs' cubic structure by lattice shrinkage, but lacking sensing research. Herein, Ni-substituting CsPbBr NCs were prepared to rapidly and accurately detect water content (WC) in edible oils. CsPbNiBr NCs had the highest fluorescence intensity, approximately 125 % of CsPbBr NCs. The results displayed that CsPbNiBr NCs were uniformly quadrilateral crystalline packing (8.78 ± 0.28 nm particle size) with inter-planar distances of 0.41, 0.33, and 0.29 nm. Given the fluorescence quenching behavior, a superior linear curve between fluorescence-decreased ratio and WC was established within 0-3 ‰ (/v) and a detection limitation of 0.042 ‰. Furthermore, excellent precision and accuracy were verified in various oils with a relative error of 2.06 %. It was suggested that water destroyed and dissolved CsPbNiBr NCs' crystal structure to induce fluorescence quenching. Thus, Pb-site substitutions of CsPbBr NCs enhanced the sensing performance, enlightening other elements-substituted CsPbBr NCs for sensing.