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.

Automated summary

To address the growing concerns about food safety, a sensor for tetracycline antibiotics was urgently needed. In this study, a series of binuclear coordination polymers (Tb-Zn-CPs) were synthesized and one particular polymer exhibited high electrochemiluminescence (ECL) intensity. A sensor utilizing this polymer was developed for sensitive detection of tetracycline, achieving good results in dairy product analysis.