Preparation and properties of hemoglobin s via seATRP in only 5 [mu]L Volumes

Hemoglobin (Hb) imprinted poly (ionic liquid)s (HIPILs) were fabricated on the surface of Pt wire modified with nano-gold (nAu) via simplified electrochemically mediated atom transfer radical polymerization (seATRP) in only 5 [mu]L volumes. The micro upgrade seATRP was mainly carried out by two platinum wires electrode. The one platinum wire was bare and applied as the counter electrode, the other one was modified segmentally, which made it could be used both as a catalytic electrode of seATRP and the substrate of HIPILs. The HIPILs were prepared by using Hb as the template, 1-vinyl-3-propyl-imidazole sulfonate (VPIS) ionic liquids and N, N'-methylene bis-acrylamide (MBA) as the functional monomer and cross-linking agent of HIPILs, respectively. When a constant current was applied to the catalytic electrode, Fe (III) in Hb would be reduced to Fe (II), seATRP of VPIS would be triggered on the surface of Pt/nAu electrode. After Hb was removed, the HIPILs modified electrode (Pt/nAu/HIPILs) was obtained. The Pt/nAu/HIPILs electrode was characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), cyclic voltammetry (CV), and electrochemical impedance spectroscopy (EIS). Further experiments indicated that the Pt/nAu/HIPILs electrode could be utilized as electrochemical sensor to determine Hb by differential pulse voltammetry (DPV). The linear response range was 1.0 x 10.sup.-12 ~ 1.0 x 10.sup.-1 mg/mL and the detection limit was 3.29 x 10.sup.-13 mg/mL (S/N = 3). Compared with other Hb sensors based on imprinting polymers, the broader linear range and lower detection limit suggested the promising prospect of the biosensor.