•Optical chemical sensing system based on SiO2 sensor layer for continuous determination of biogenic amines.•Indicator dye ETH4001 was immobilized in silica matrix composed of organosilica ...precursors.•Selectivity for aliphatic amines, such as isopentylamine, propylamine, putrescine.
This study presents an optical chemical sensing system based on an SiO2 sensor layer for continuous determination of biogenic amines (BAs), such as isopentylamine, propylamine and putrescine. For this purpose, the indicator dye ETH4001 was chosen and immobilized in different sol-gel sensor layers, which were prepared by various combinations of hydrophilic tetraethoxysilane and hydrophobic sol-gel precursors propyl-trimethoxysilane, and 3,3,3-trifluoropropyltrimethoxysilane. The preparation of the starting sol-gel solution containing the indicator ETH4001 was carried out via the acid-catalyzed process and at a constant molar ratio R=7 in all cases. The sensing system was optimized according to spectral properties, dynamic range, sensitivity, response and regeneration time and sensor layer aging time.
