Amino-functionalized Al-MOF modulated TpTt-COF with dual-emission for fluorescent and optosmart detecting tetracycline in food samples

•NH2-MIL-53(Al) as modulator enhances fluorescence dual-emission of TpTt-COF.•Benzene ring of the probe recognizes tetracycline through π-π interactions.•Fluorescence quenching via N/O of the probe and −OH/−NH2 of tetracycline.•Limit of detection of 0.014 μmol/L and recoveries of 94.39–105.67% are achieved.•The optosmart sensing system is applied to visual detection of tetracycline.