Colorimetric detection of Ni2+ based on an anionic triphenylmethane dye and a cationic polyelectrolyte in aqueous solution

Abstract

The combination of xylenol orange (XO) and poly(diallyldimethylammonium chloride) (PDADMAC) has been utilized as a colorimetric sensor for selective recognition of Ni2+ in aqueous solution. Upon addition of Ni2+, the chemosensor exhibited the significant color change from red to purple with a bathochromic shift, whereas these change was not induced by other metal ions. XO alone did not recognize Ni2+ colorimetrically, indicating that PDADMAC was required for detecting Ni2+. This study can provide the facile method for the construction of new chemosensors by a simple mixture of an anionic water-soluble dye and cationic polyelectrolyte.