A CsPb_0.95Ni_0.05Br₃ NCs-based fluorescence sensor for rapidly and accurately evaluating trace water in edible oils...

Metal ions with smaller radii than Pb²⁺ can stabilize CsPbBr₃ NCs' cubic structure by lattice shrinkage, but lacking sensing research. Herein, Ni-substituting CsPbBr₃ NCs were prepared to rapidly and accurately detect water content (WC) in edible oils. CsPb_0.95Ni_0.05Br₃ NCs had the highest fluorescence intensity, approximately 125 % of CsPbBr₃ NCs. The results displayed that CsPb_0.95Ni_0.05Br₃ 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/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 CsPb_0.95Ni_0.05Br₃ NCs' crystal structure to induce fluorescence quenching. Thus, Pb-site substitutions of CsPbBr₃ NCs enhanced the sensing performance, enlightening other elements-substituted CsPbBr₃ NCs for sensing.