Surface plasmon resonance sensor based on Bi-monomer System (BMS) molecularly imprinted polymer for detection of 17β-estradiol in aqueous media

In this work, a hydrophilic and high sensitivity sensor was fabricated based on BMS (MAA : HEMA = 3 : 1, molar ratio) molecularly imprinted polymers (MIPs) film for 17β-estradiol (E2) detection in aqueous media combined with surface plasmon resonance (SPR) technique. In-situ UV polymerization method was used to synthesize the MIPs film on the gold surface which was modified with dodecyl mercaptan. Afterwards, the MIPs film was characterized by infrared spectroscopy (IR), scanning electron microscope (SEM) and contact angle measurements. The results showed that the MIPs film was successfully prepared on the surface of the sensor chip with good hydrophilicity and permeability. The analysis of SPR spectroscopy indicated that the MIPs film displayed greater selectivity to E2 than other competitors and non-imprinted polymers (NIPs) film and showed better adsorption performance than one kind of monomer for the same E2 concentration. The response of E2 sensor ranged from 2.5×10^-16 to 2.5×10^-8 mol/L with an ultra-low detection limit of 9.14×10^-18mol/L in PBS buffer (pH 7.4). In addition, this sensor performed good reusability and stability. Finally, the sensor was successfully applied to detect E2 in tap water and human urine and had wide detection ranges and low detection limits in backgrounds.