Surface-molecularly imprinted ratiometric fluorescence sensor for fast, sensitive and selective determination of rhodamine 6G

Rhodamine 6G (Rh6G) is a classic dye that has been banned as a food additive due to its harm to human bodies. The illegal addition of Rh6G in foods should be strictly monitored. In this study, a surface-molecularly imprinted fluorescence sensor (TPP-SMIPs) for Rh6G detection was prepared on SiO2 using an aggregation-induced emission molecule as a fluorescence signal part. TPP-SMIPs exhibited ratiometric response to Rh6G. Favorable linearity between the fluorescence intensity ratios and Rh6G was obtained in the range of 0–10.0 μmol/L. Better site accessibility and higher mass transfer rate were achieved in TPP-SMIPs than in non-surface imprinted polymers. High sensitivity with a low detection limit (2.82 nmol/L) and excellent selectivity were also realized in TPP-SMIPs. Its applications in real sample detection showed satisfactory recoveries and relative standard deviations. This study demonstrated that this sensor can provide fast, sensitive and selective determination to Rh6G in real samples. This work not only reported a new detection method for rhodamine dyes, but also provided a universal strategy for the design of high-performance molecularly imprinted fluorescence sensors.