Novel electrochemiluminescence luminophore based on flower-like binuclear coordination polymer for high-sensitivity detection of tetracycline in food products

To meet the growing concerns about food safety, sensors for tetracycline antibiotics have been urgently needed. Herein, we synthesized a series of binuclear coordination polymers (Tb-Zn-CPs) based on lanthanide and transition metal ions by solvothermal method using [1,1':4',1''-terphenyl]-3,3'',5,5''-tetracarboxylic acid, Tb(NO3)3 and Zn(NO3)2. The morphologies and electrochemiluminescence (ECL) performances of Tb-Zn-CPs varied with different molar ratios of terbium and zinc ions (Tb:Zn). The flower-like Tb-Zn-CP (9:3) possessed the highest ECL intensity due to the ligand antenna effect and the sensitization of Zn2+. An ECL sensor for the detection of tetracycline (TC) was constructed utilizing Tb-Zn-CP (9:3) as a novel ECL luminophore and potassium persulfate as a coreactant. The proposed sensor achieved sensitive detection of TC in the range of 5.0 fmol·L-1 to 3.0 mmol·L-1 with a low limit of detection (1.6 fmol·L-1). It also was applied for TC detection in dairy products with good recovery rates.