Iron telluride nanorods-based system for the detection of total mercury in blood

We have developed a simple, colorimetric iron telluride (FeTe) nanorods (NRs) based system for the detection of mercury, mainly based on the cation exchange reaction between FeTe NRs and Hg2+. FeTe NRs (length, 105 +/- 21 nm) react with Hg2+ to form HgTe NRs (length, 112 +/- 26 nm) and consequently release Fe2+ ions that catalyzes the oxidation between a peroxidase substrate 2,2'-azino-bis(3-ethylbenzo-thiazoline-6-sulfonic acid) diammonium salt (ABTS) and H2O2. The concentration of Fe2+ and thereby Hg2+ can be determined by measuring the absorbance of the ABTS oxidized product at 418 nm. This approach allows the detection of Hg2+, with a limit of detection of 1.31 nM at a signal-to-noise ratio 3 and a linear range 5-100 nM (R-2 = 0.99). The low-cost, simple, sensitive, and reproducible assay has been validated for the detection of Hg2+ in a blood sample (SRM 955c), with the result being in good agreement with that provided by National Institute of Standards and Technology. (C) 2012 Elsevier B.V. All rights reserved.