Colorimetric detection of Hg(2+) using gold nanoparticles synthesized by Trichosporon montevideense WIN.

OBJECTIVE: To investigate a simple, cost-effective and eco-friendly method for colorimetric detection of Hg(2+) using gold nanoparticles (AuNPs) synthesized by Trichosporon montevideense WIN. RESULTS: Hg(2+) induced more visible blue shift of SPR band of the AuNPs than other heavy metal ions including Pb(2+), Cd(2+), Fe(3+), Mn(2+), Co(2+) and Cu(2+). The lambdamax of SPR band exhibited a gradual blue shift from 548 to 537 nm with concentration of Hg(2+) increasing (0-200 microM), and the absorbance ratio (A537/A548) showed a positive linear correlation with Hg(2+) concentration (R(2) = 0.96). AuNPs synthesized at pH 6 showed more obvious blue shift than at pH 5 and pH 7. Through Fourier transform infrared (FTIR) spectroscopy and transmission electron microscopy (TEM) analysis, biomolecules coated on the AuNPs were speculated to dominate the formation of a core (Au)-shell (Hg) structure, which resulted in the colorimetric response. CONCLUSION: A sensitive and selective approach to detect Hg(2+) using AuNPs synthesized by Trichosporon montevideense WIN is reported for the first time, which can provide a new potential candidate for detecting Hg(2+) in the future.