【Purpose】Increased awareness about celiac disease (CD) has resulted in a wider availability of gluten-free products, but gluten can still be consumed through cross-contamination. An aptamer-based capacitive biosensor was developed for analyzing gliadin, the main allergenic gluten protein for CD.
【Methods】Parylene was coated onto the SPCE by CVD. The amino-modified aptamer was crosslinked to the inherent amino groups of Parylene by glutaraldehyde. The capacitance change resulting from the binding between the aptamer and gliadin was monitored by an LCR meter.
【Results】With the optimal functionalized insulation layer of 1400 nm Parylene double-layer, the constructed capacitive biosensor can operate within a dynamic linear range of 10–1000 ppm, with an LOD value of 7 ppm for analyzing gliadin. This LOD value, equivalent to 14 ppm of gluten, satisfies the legislated threshold required for verifying gluten-free products.
