Three-Dimensional Polymeric Biointerface for Ultra-Sensitive and Selective Detection of Low-Molecular-Weight Biomarker Using Semiconductor-Based Biosensor

Abstract

In this study, we report a novel approach towards a highly sensitive and selective detection of low-molecular-weight biomolecules. An extended-Au gate field-effect transistor biosensor showed a high detection sensitivity to various biomolecules; therefore, a chromatographic effect was supplied with polymeric membranes (polyfilter) on the Au gate surface so that only a small biomolecule as target (L-cystine as model) reached the sensing surface through the polymeric membrane, while the polymeric membrane as a filter captured various impurities (L-DOPA as model) outside the Debye length. As a result, the detection limit of the sensor towards L-DOPA was significantly suppressed by the filter-coated sensor, while not affecting the limit of L-cysteine detection. Thus, the possibility of both an ultra-sensitive detection of small biomolecules and a filtering effect was clearly verified.