Analytical Sciences

Abstract − Analytical Sciences, 26(11), 1169 (2010).

Visual Detection of Hg2+ with High Selectivity Using Thymine Modified Gold Nanoparticles
Xiangjun LIU, Xiaohong CHENG, Tao BING, Canliang FANG, and Dihua SHANGGUAN
Beijing National Laboratory for Molecular Sciences, Key Laboratory of Analytical Chemistry for Living Biosystems, Institute of Chemistry, Chinese Academy of Sciences, Beijing 100190, P. R. China
Here, we describe a colorimetric sensor for detecting Hg2+ in aqueous media, which is simply constructed by the self-assembly of thymine acetamidoethanethiol (T-SH) on gold nanoparticles (AuNPs). Based on the specific interaction of Hg2+ with two thymines (T), the T-SH modified AuNPs can be induced to aggregate through the formation of a stable T-Hg-T complex in the presence of Hg2+, resulting in a color change from red to blue-gray. As low as 0.5 μM of Hg2+ can be easily monitored by the naked eye using this sensor. Other metal ions, including Zn2+, Cd2+, Pb2+, Ni2+, Cu2+, Co2+, Mn2+, Ba2+, Fe2+, Ca2+, Mg2+, Al3+, and Fe3+, could not cause any response, even at concentrations 100-fold higher than Hg2+. The high selectivity, high stability and easy operation enable this sensor suitable for the rapid on-site detection of Hg2+ pollution.