Preparation of hemoglobin (Hb) imprinted polymers with CO2 response and its biosensing application

A novel hemoglobin (Hb) imprinted polymers with CO2 response (CHIPs) were prepared on the surface of Au electrode modified by zinc oxide (CHIPs/ZnO/Au) via electrochemically mediated atom transfer radical polymerization (eATRP). The imprinted polymers were synthesized with Hb both as catalyst and template, and N,N-diethylaminoethyl methacrylate (DEAEMA) as CO2-responsive functional monomer. The obtained CHIPs/ZnO/Au electrode was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), and electrochemical methods. The results showed that CHIPs/ZnO/Au electrode could give higher affinity for the target protein inside a CO2-treated aqueous medium compared to that under N-2-treated conditions, which make it a good electrochemical biosensor in the presence of CO2. The biosensor could be successfully applied for the determination of Hb by differential pulse voltammetry (DPV) measurement. The linear response range of CHIPs/ZnO/Au for detecting Hb was 1.0x10(-12)similar to 1.0x10(-1) mg L-1 and the detection limit was 2.1x10(-13) mg L-1 (S/N=3). Briefly, the work in this study introduced an easy and non-toxic method for Hb determination under specific conditions and also provided a progressive approach for designing protein imprinted polymers.