A novel optosensing chip was constructed by anchoring the fluorescence sensing material layer based on molecularly imprinted polymer (MIP) coated CdSe/ZnS quantum dots (QDs) on a chip for highly selective and sensitive optosensing of sesamol in sesame oil. Many factors that affected the performance of the optosensing chip based on MIP-coated QDs are discussed. Under optimized conditions, the relative fluorescence intensity of the optosensing chip decreased linearly (r(2) > 0.99) with increasing sesamol concentration in the range from 2.4 × 10(-6) to 1.2 × 10(-3) mol L(-1) with a detection limit of 7.2 × 10(-8) mol L(-1). The relative standard deviation for five replicate detections of 4.8 × 10(-4) mol L(-1) sesamol was 2.2%. Recoveries of 94.8-102.3% were achieved by direct detection when the optosensing chip was used for the selective detection of sesamol in sesame oil. Practically, the optosensing approach showed high sensitivity, good selectivity, and excellent reproducibility for the detection of sesamol in real oil samples.
Keywords: molecularly imprinted polymers; optosensing chip; quantum dots; sesamol.