LAUSR

Herein we report the twin advantages of a white light emitting-quantum dot complex (WLE-QDC), comprising Mn2+-doped ZnS quantum dots (Qdots) and zinc quinolato (ZnQ2) complex, towards selective recognition of long chain unsaturated fatty acids (LCUFAs; e.g., Na-salt of oleic acid) from their corresponding saturated forms (e.g., Na-salt of stearic acid). Importantly, WLE-QDC provided unique ratiometric visual detection of LCUFAs with a detection limit of 0.127 I¼M in the linear range of 4.2-16.6 I¼M. This was pursued by monitoring the alterations in the photoluminescence color from white to cyan, hue, chromaticity and emission intensity ratio (I480/I590) of WLE-QDC when interacted with LCUFAs. The concurrent hydrophobic and I€-I€ interactions between ZnQ2 complex (present in WLE-QDC) and LCUFAs might have played important roles in this regard. Remarkably, the high selectivity of WLE-QDC towards LCUFAs led to their practical utilization in quantification of LCUFAs in commercial vegetable oils.