A selective colorimetric chemosensor for detecting SO32- in neutral aqueous solution

As a colorimetric anion sensor, the non-covalent charge-transfer complex, formed by di(hydroxymethyl)-di-(2-pyrrolyl) methane 1 and TCNQ 2, may be used for higher sensitive and selective detection of SO32- than other inorganic anions in a neutral buffered aqueous system. The excellent system properties is hopeful to be used in the monitoring fields of food products and environmental pollutant.

The colorimetric sensor based on the charge-transfer complex showed high sensitivity for SO32- in a neutral buffered water/organic solvent system. The experiments confirmed that the color change of the dipyrromethane-TCNQ complex solution in the presence of SO32- is ascribed to the competitive binding of SO32- to TCNQ subunit and is proved to be a reversible procedure.Figure optionsDownload as PowerPoint slide