Molecularly imprinted poly(o-phenylenediamine) coated ZIF-5-Ru(bpy)32+ composite for the sensitive and selective ECL detection of tetracycline

The widespread use of tetracycline unavoidably causes residue problems, hence its monitor in foods and environment is important. In this work, a simple but sensitive electrochemiluminescence (ECL) sensor is prepared for tetracycline detection. The sensor is constructed using TiO2 nanoparticle, ZIF-5 loaded Ru(bpy)32+ (Ru@ZIF-5), and molecularly imprinted poly-o-phenylenediamine. The TiO2 NP acts as a co-reaction accelerator for tri-n-propylamine (TPrA) by producing electrons and holes at a certain potential to promote the production of TPrA. ZIF-5 has a large specific surface area and rich functional groups, thus can well immobilize a large amount of illuminant Ru(bpy)32+. The electrodeposited molecularly imprinted polymer acts as a recognition element. Due to the synergic effect of different components, the resulting ECL sensor shows a wide linear range of 10 nM–50 μM, high selectivity, low detection limit, and good stability. It can be used for the detection of tetracycline in food and environmental samples.