title: Selective electrochemical sensing of human serum albumin by semi-covalent molecular imprinting.
abstract: We devised and prepared a conducting molecularly imprinted polymer (MIP) for human serum albumin (HSA) determination using semi-covalent imprinting. The bis(2,2'-bithien-5-yl)methane units constituted the MIP backbone. This MIP was deposited as a thin film on an Au electrode by oxidative potentiodynamic electropolymerization to fabricate an electrochemical chemosensor. The HSA template imprinting, and then its releasing from the MIP was confirmed by the differential pulse voltammetry (DPV), electrochemical impedance spectroscopy (EIS), XPS, and PM-IRRAS measurements as well as by AFM imaging. Semi-covalent imprinting provided a very well defined locations of recognition sites in the MIP molecular cavities. These sites populated the imprinted cavities or the MIP surface only. The DPV and EIS response of the MIP film coated electrode to the HSA analyte was linear in the range of 0.8 to 20 and 4 to 80 µg/mL HSA, respectively, with the limit of detection of 16.6 and 800 ng/mL, respectively. The impressively high imprinting factor reached, exceeding 20, strongly confirmed that semi-covalent imprinting resulted in formation of a large number of very well defined molecular cavities with high affinity to the HSA molecules. The MIP selectivity against low-(molecular weight) interferences, common for physiological fluids, such as blood and urea, was very high. There was no response to the presence of these interferences at concentrations encountered in the samples analyzed. Moreover, the chemosensor selectivity to the myoglobin and cytochrome c interferences was excellent while that to lysozyme was slightly lower but still high. The chemosensor was useful for determination of abnormal HSA concentration in a control blood serum.
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland. Electronic address: mcieplak@ichf.edu.pl.
authors.forename: Maciej
authors.initials: M
authors.lastname: Cieplak
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland; Institute of Chemistry and Technical Electrochemistry, Poznan University of Technology, Berdychowo 4, 60-965 Poznan, Poland.
authors.forename: Katarzyna
authors.initials: K
authors.lastname: Szwabinska
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland; Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, USA.
authors.forename: Marta
authors.initials: M
authors.lastname: Sosnowska
authors.affiliation: Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, USA.
authors.forename: Bikram K C
authors.initials: BK
authors.lastname: Chandra
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland; Institute of Electron Technology, Al. Lotnikow 32/46, 02-668 Warsaw, Poland.
authors.forename: Pawel
authors.initials: P
authors.lastname: Borowicz
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland.
authors.forename: Krzysztof
authors.initials: K
authors.lastname: Noworyta
authors.affiliation: Department of Chemistry, University of North Texas, 1155 Union Circle, #305070, Denton, TX 76203-5017, USA.
authors.forename: Francis
authors.initials: F
authors.lastname: D'Souza
authors.affiliation: Institute of Physical Chemistry, Polish Academy of Sciences (IPC PAS), Kasprzaka 44/52, 01-224 Warsaw, Poland; Faculty of Mathematics and Natural Sciences, School of Science, Cardinal Stefan Wyszynski University in Warsaw, Wóycickiego 1/3, 01-815 Warsaw, Poland.
authors.forename: Wlodzimierz
authors.initials: W
authors.lastname: Kutner
mesh_terms: D015374:Biosensing Techniques / Q000295:instrumentation*; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006801:Humans; D054802:Molecular Imprinting / Q000379:methods*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012709:Serum Albumin / Q000032:analysis* / Q000737:chemistry*
chemical_list: D012709:Serum Albumin
keywords: Blood serum albumin; Differential pulse voltammetry; Electrochemical chemosensor; Electrochemical impedance spectroscopy; Human serum albumin; Molecularly imprinted polymer (MIP); Semi-covalent imprinting; Thiophene conducting polymer