Colorimetric Determination of Pb²⁺ Based on Ionochromic Polydiacetylene/Anionic Surfactant Materials

Abstract

The purpose of this work was to develop efficient ionochromic polydiacetylenes for lead ion (Pb2+) detection. The method developed used co-assemblies of polydiacetylene and anionic surfactant. The co-assemblies were prepared by mixing 10,12-pentacosadiynoic acid (PCDA) with sodium dodecyl sulphate (SDS) and subsequent UV irradiation-polymerization. The effects of mole ratio of PCDA to SDS, detection limit and stability were investigated. A color transition of poly(PCDA/SDS) co-assemblies with Pb2+ from blue to red was directly observed without the use of any technological equipment. However, Ni2+ and Fe3+ were non-responsive. The co-assemblies of poly(PCDA/SDS) showed rapid ionochromic response and selectivity to Pb2+ in aqueous solution. Based on this approach, the reagent has many advantages such as simple preparation, low cost, low chemical consumption and fast analysis. It is an alternative method for the development if sensing material for the detection of metal ions contaminating the environment.