Search

Today there is growing interest in the replacement of biological receptors in biosensing systems including point-of-care (PoC) diagnostics devices due to their high price and short shelf life. Molecularly imprinted polymers (MIPs), which are wholly synthetic materials with antibody-like ability to bind and discriminate between molecules, demonstrate improved stability and reduced fabrication cost as compared with biological receptors. Here we report, for the first time, a MIP-based synthetic receptor capable of selective binding of a clinically relevant protein - the brain-derived neurotrophic factor (BDNF). The BDNF-MIP was generated by surface-initiated controlled/living radical photopolymerization directly on a screen-printed electrode (SPE). The resulting BDNF-MIP/SPE electrochemical sensor could detect BDNF down to 6 pg/mL in the presence of the interfering HSA protein and was capable of discriminating BDNF among its structural analogues, i.e. neurotropic factors CDNF and MANF. We believe that the presented approach for the preparation of a neurotrophic factor-selective sensor could be a promising route towards the development of innovative PoC diagnostics devices for the early-stage diagnostics and/or monitoring the therapy of neurological diseases. [ABSTRACT FROM AUTHOR]

This study demonstrates the promising steps towards improving the detection of small analytes in an aqueous solution by the quartz crystal microbalance (QCM) modified with a molecularly imprinted polymer (MIP) based sensitive layer. A homogeneous thin polymer film of poly(m-phenylenediamine) (PmPD) was electrochemically deposited on the surface of a QCM sensor in the presence of sulphamethizole (SMZ) acting as a template molecule. The binding capacity of the resulting SMZ-MIP films was enhanced by modifying the sensing surface with a diethylaminoethyl-dextran (DEAE-Dex) layer, forming a SMZ-MIP(Dex) film. The dextran layer allows further preconcentration of template molecules on the sensor electrode before polymer electrodeposition. The relative adsorption of the SMZ-MIP(Dex) films, as designated by the imprinting factors, was found to be in all cases significantly higher than that of the other films. At least about three times enhanced relative binding capacity of the modified imprinted polymer on the QCM sensor was established. A probe of the analysed sensor signals revealed that the modification steps significantly reduced the contribution from nonspecific interaction of the polymer matrix, thus suggesting beneficial effects of the dextran modification and template preconcentration. The presented approach promises a positive route towards an improved specific detection of small molecules by molecular imprinting on QCM sensor transducers. [ABSTRACT FROM AUTHOR]

Copyright of Proceedings of the Estonian Academy of Sciences is the property of Teaduste Akadeemia Kirjastus and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)