Colorimetric Chemosensor Array for Determination of Halides

The halide anions are essential for supporting life. Therefore, anion analyses of paramount importance. For this reason, we have performed both qualitative and quantitative ana- lyses halides (chloride, bromide, iodide) using the Tl(III) complex azodye, 4-(2-pyridylazo)re- sorcinol (PAR), a potential new chemical reagent/sensor that utilizes substitution reaction whereas Tl(III)PAR reacts with to yield more stable thallium(III)-halide while releasing PAR ligand in process accompanied by color change solution. experimental conditions (e.g., pH, ratio metal ion-to-ligand ratio, etc.) between were optimized achieve increased sensitivity lower limit detection (chloride 7 mM, bromide 0.15 iodide 0.05 mM). It is demonstrated single chemosensor can, due release colored associated analyte-specific changes UV/VIS spectra, be employed multicomponent analysis mixtures + chloride iodide, iodide). spectrophotometric data evaluated artificial neural networks (ANNs) enable distinguishing among determine species concentrations mixture. Tl(III)-PAR was also used construct sensor arrays utilizing standard 96-well plate format where output recorded at several wavelengths (up 7) conventional reader. shown obtained digital scanner employing only three different input channels may successfully subsequent ANN analysis. results all approaches utilized evaluation similar. To increase practical utility chemosensor, developed test paper strip indicator useful routine naked-eye visual determination halides. This can solutions densitometer. methodology described simple, inexpensive, fast laboratory as well field setting.