Elektrokimyasal analiz için moleküler baskılı polimer bazlı valine biyosensörünün geliştirilmesi

Molecule imprinting technique (MIP) is an important tool in the preparation of intelligent three-dimensional polymeric materials, which are highly selective and are able to recognize the structure of the analyte with a unique recognition feature. In this study, a sensitive and stable electrochemical valine MIP biosensor was developed on gold disc electrodes and tested for selectivity and specificity. A hydrogel with molecule imprinted valine was formulated and polymerized on gold electrode; followed by the removal of valine molecules from the electrode surface, creating valine recognition sites. The electrodes with different amounts of valine recognition sites were tested using cyclic voltammetry and electrochemical impedance spectroscopy in solutions containing different concentrations of valine. The current, voltage and impedance response of the electrode to varying valine concentration was investigated. In this study, ten different concentrations of valine receptors were imprinted on gold electrodes with the removal of the template molecule to form molecule-recognizing regions (Au-MIP) and template molecule not removed (Au-UMIP) and control electrodes without any imprinted template molecules (Au-NIP). A total of twenty one gold electrodes were analyzed in phosphate buffer solution (pH=5). Au-MIP electrodes imprinted at 0.3M displayed a linearly regressed increase in impedance in the 10-18 to 10-6 M dynamic range, with a LOD of 9.76E-17 M and LOQ of 7.18E-15 M. Valine imprinted electrode selectivity factor (α) was 3.96, 4.19, and 92.76 times higher for Valine than glycine, alanine and methionine, respectively. The imprinting factor (β) values indicated that the valine imprinted biosensor (MIP) was more selective for valine than the control electrode (NIP), in presence of the interfering molecules glycine, alanine and methionine, at a ratio of 4.13, 4.41 and 96.63 respectively. RSD percent for intra- and inter-day precision were obtained as 2.3 percent and 8 percent respectively. The valine imprinted electrodes had 98.69±9.32 percent stability on day-45 with a RSD percent of 9.44. Our results indicate that the MIP biosensor developed for electrochemical analysis has displayed higher specificity than the conventional electrochemical analysis methods.