DFT-guided design of molecularly imprinted sensor for fluorescence and visualization dual-mode oxytetracycline...

Developing highly specific sensors is crucial for monitoring oxytetracycline (OTC) residues in food. Herein, a fluorescence-visual dual-mode sensor Eu,S-CQD@D_ZIF-8@MIP (EDMIP) was constructed via a computation-aided rational design. Firstly, density functional theory (DFT) and electronic potential (ESP) analysis were employed to screen for the functional monomer (3-aminopropyl) triethoxysilane (APTES) with the lowest binding energy to the target compound OTC. Guided by these theoretical insights, a molecularly imprinted polymer (MIP) layer was synthesized on the surface of an interpenetrating metal-organic framework (D_ZIF-8), with Eu,S-CQDs serving as the signal elements, which enabled highly selective recognition of OTC and rapid adsorption equilibria (7 min). Simultaneously, EDMIP exhibited a wide linear range (0.05-20 μg mL^-1) and a low detection limit (2.31 ng mL^-1), while its integration with a smartphone further enabled portable visual detection, demonstrating the synergy of theoretical simulation and structural engineering in advanced material construction.