Metal organic framework-based tricolor fluorescence imprinted sensor for rapid intelligent detection of homovanillic acid

Homovanillic acid (HVA) is one of the main metabolites of catecholamines in the body. Abnormal levels of HVA in urine and serum are associated with neuroblastoma and Parkinson's disease. Herein, a smartphone-assisted tricolor fluorescence imprinted sensor was proposed with one-pot synthesis strategy for the intelligent determination of HVA in serum and urine. In this study, luminescent metal–organic framework was used as reference probe, while green-emitting CdTe and red-emitting CdTe were used as response probes. With increasing HVA concentration, the green-emitting CdTe and red-emitting CdTe fluorescence were gradually quenched, while the blue fluorescence of metal–organic framework remained stability. The tricolor fluorescence imprinted sensor extends the color variations range for visual detection with dynamic detection range (0.05–180 µM). The fluorescence imprinted sensor exhibits a lower detection limit of 15 nM and rapid response within 2 min. Interestingly, a portable smart sensing platform was designed by integrating the tricolor fluorescence imprinted polymer and a smartphone assisted device to achieve on-site accurate analysis HVA with a detection limit of 34 nM. The sensing platform was applied to in situ monitoring of HVA in serum and urine with satisfactory results, providing a new method for visual intelligent detection of HVA.