Precisely size-controlled CsPbBr3 NCs for detecting peroxide value in edible oils with moisture-compensation

Size and shape critically influence the optical properties of CsPbBr 3 NCs, but lack sufficient research in sensing. Herein, particle sizes and shapes of CsPbBr 3 NCs were precisely adjusted by room-temperature synthesis method, and sensing performances to peroxide value (PV) of edible oils were investigated. The results found that the particle sizes (4.3 ± 0.2, 6.3 ± 0.2, 8.8 ± 0.3, and 12.9 ± 0.6 nm) of high-crystallized cubic CsPbBr 3 NCs were precisely obtained, and the fluorescence (from 491 to 516 nm) and absorption (from 470 to 526 nm) peak wavelengths redshifted as the particle size increased from 4.3 nm to 12.9 nm. Among four particle sizes, CsPbBr 3 NCs (8.8 nm) demonstrated the optimal sensing performance (wavelength-shifted colorimetric method R 2  = 0.99) for PV detection, achieving a linear response range of 0.02–0.36 g/100 g with LOD of 0.0022 g/100 g and LOQ of 0.0073 g/100 g. Considering the interference from trace moisture in edible oil, a moisture-compensated intensity-quenched colorimetric method was proposed to improve the practical accuracy, with the practical recovery rates from 95%–245% to 90%–119%. Therefore, the proposed methods had good sensitivity, accuracy and practicability, and enlightened the effective technologies for the quality detection of edible oil.