Fabrication of molecularly imprinted polypyrrole /Ru@ethyl-SiO2 nanocomposite for the ultrasensitive electrochemiluminescence sensing of 17β-Estradiol

Abstract

A solid-state electrochemiluminescence (ECL) sensor for the highly selective and sensitive detection of 17β-estradiol (E2) is presented. The sensor is constructed with Ru(bpy)32+ doped vinyl-SiO2 nanoparticles (Ru@ethyl-SiO2) and E2 imprinted polypyrrole (MIP). The Ru@ethyl-SiO2 nanoparticles act as luminophores, while the MIP provides recognition sites for E2. As the adsorbed template molecules can act as co-reactant for Ru@ethyl-SiO2, the ECL intensity increases with the adsorption amount of E2 rising, which depends on its concentration in the solution. Owing to the well combination/or synergy of the smart MIP and the high-effective ECL material, the resulting sensor exhibits highly selective and ultrasensitive response to E2. Under the selected conditions, the ECL intensity increment (ΔI) is linear to the logarithm of E2 concentration over the range from 0.01 to 100 pg mL−1, and the detection limit is down to 0.005 pg mL−1 (S/N = 3). The ECL sensor also shows good reproducibility and repeatability. It has been successfully applied to the detection of E2 in tea and oral solution samples and the recoveries are 87.7%–115.3%.