Picric acid sensitive optode based on a fluorescence carrier covalently bound to membrane

Abstract

An acryloyl group was attached to fluorescein through the phenol hydroxyl group to make it photopolymerizable with 2-hydroxypropyl methacrylate and covalently immobilized on an optode glass surface modified with γ-(methacryloxy)propyltrimethoxysilane. The optode system with a plastic-clad fused silica bifurcated fiber optic bundle shows satisfactory analytical performance characteristics for determining picric acid in terms of selectivity and reproducibility with a linear range from 8.0 × 10⁻⁷ to 4.0 × 10⁻³ mol L⁻¹. The quenching mechanism was investigated. The optode membrane can be applied to the indirect determination of cinchonine drug and the results obtained were satisfactory.