Down/up-conversion dual-mode ratiometric fluorescence imprinted sensor embedded with metal-organic frameworks for dual-channel multi-emission multiplexed visual detection of thiamphenicol.

The establishment of a fluorescence sensing system for sensitive and selective visual detection of trace antibiotics is of great significance to food safety and human health risk assessment. A simple and rapid one-pot strategy was developed successfully to synthesize a down/up-conversion dual-excitation multi-emission fluorescence imprinted sensor for dual-channel thiamphenicol (TAP) detection. In this strategy, the metal-organic frameworks were in situ incorporated into the fluorescence imprinted sensor, guiding the coordination induced emission of abiotic carbon dots and signal-amplification effect of fluorescence sensing. Under dual-excitation (370 nm and 780 nm), the fluorescence imprinted sensor exhibited a dual-channel fluorescence response toward TAP with two-part linear ranges of 5.0 nM-6.0 μM and 6.0 μM-26.0 μM. Significantly, the fluorescence color ranged from blue to purple to red can be observed with the naked eye. The results of the dual-channel TAP determination in actual samples by the fluorescence imprinted sensor indicated that the fluorescence imprinted sensor provided a sensitive, selective, and multiplexed visual detection of TAP in complex sample.
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