Colorimetric detection of Hg2+ 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 λ max of SPR band exhibited a gradual blue shift from 548 to 537 nm with concentration of Hg 2+ increasing (0–200 µM), and the absorbance ratio (A 537 /A 548 ) 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.