Sensing of lead ions using glutathione mediated end to end assembled gold nanorod chains

This communication reports the use of glutathione mediated self assembled chains of gold nanorods as new approach for the detection of Pb(2+) ions. We were prompted to study the influence of metal ions by considering the role of glutathione as detoxification agent in the body. Additionally the ability of glutathione to complex with metal ions like lead (Pb(2+)) and mercury (Hg(2+)) is well known. We studied the interaction of different metal ions including Pb(2+) with the end to end assembled chains of gold nanorods. Pb(2+) was found to disassemble the chains to dimeric structures. High resolution transmission electron microscopy and dynamic light scattering were used to study the ensemble. A proportional reduction in the size of the assembly was observed between concentration ranges of 0.1-0.025 mM of Pb(2+). Our results indicate that analyte induced disassembly is an attractive approach to the detection of environmentally relevant components such as Pb(2+). (C) 2011 Elsevier B.V. All rights reserved.