Abstract:

The molecularly imprinted polymers （MIPs） for human serum albumin （HSA） are prepared via metal-free visible-light-induced atom transfer radical polymerization （MVL ATRP） on the surface of Pt ultramicroelectrodes （Pt UME） that have been covered with electrodeposited nano gold （nAu）. In the preparation process， the fluorescein isothiocyanate labeled HSA （FITC-HSA） is used both as template molecules of MIPs and the catalyst of MVL ATRP. The obtained MIPs/nAu/Pt UME electrode is characterized by scanning electron microscope， energy dispersive X-ray spectroscopy， cyclic voltammetry， electrochemical impedance spectroscopy and X-ray photoelectron spectroscopy. Furthermore， platinum microelectrode works as the reference electrode， MIPs/nAu/Pt UME is used as working electrode and platinum wire is used as the counter electrode， a microvolume detection system of only 5 μL is constructed and used to detect HSA by differential pulse voltammetry method. Under the optimal conditions， the MIPs/nAu/Pt UME electrode （sensor） could determine HSA in the linear range from 1.0×10^-9 to 1.0×10^-2 mg/L with a detection limit of 3.4×10^-10 mg/L （S/N=3）， and the correlation coefficient of 0.9980. With hemoglobin， myoglobin，mouse IgG and bovine serum albumin （BSA） as interferers， MIPs/nAu/Pt UME electrode shows good selectivity toward HSA. The reproducibility and consistency of the sensor is also investigated. Finally， the actual samples of human serum are determined by the standard addition method. The obtained recovery of HSA is from 96.0% to 104.5%， showing its potential applications in clinical and diagnostic research.

Key words: Metal-free visible-light-induced atom transfer radical polymerization, Ultramicro imprinting sensor, Human serum albumin, Microvolume detection