Water dispersible glycylglycine functionalized gold nanoparticles: application in colorimetric sensing of Hg(II), Pb(II) and Cr(III) in aqueous media
RAVI GUNUPURU DEBDEEP MAITY GAURAV VYAS PARIMAL PAUL
Click here to view fulltext PDF
Glycylglycine functionalized water-dispersible gold nanoparticles (AuNPs) were prepared andcharacterized on the basis of ultraviolet and visible spectroscopy (UV-vis), Fourier transform infrared (FTIR),dynamic light scattering (DLS), transmission electron microscope (TEM) and energy dispersive X-ray (EDX)analysis. The AuNPs exhibited a strong SPR band at 522 nm, which after functionalization with glycylglycine,appeared at 525 nm. This SPR band of the functionalized nanoparticles is used as a tool for thedetection of toxic metal ions in water. A large number of metal ions were tested, among which Hg2+, Pb2+,and Cr2+ exhibited distinct colour change, detectable with bare eye, and substantial UV-vis spectral change.TEM images and EDX analysis suggested that the colour change is due to metal-induced aggregation of thefunctionalized nanoparticles due to inter-particle plasmon coupling. The aggregation, which resulted in anincrease in particle size, is further confirmed by DLS measurement. A mechanism of metal-induced aggregationis also proposed. The present study is an example of a simple methodology to prepare water-dispersiblefunctionalized nanoparticle for colorimetric detection of toxic heavy metal ions such as Cr2+, Pb2+,and Hg2+ with high sensitivity.
Synopsis Glycylglycine functionalized water dispersible gold nanoaprticles were prepared, characterized and its metal-ion sensing property was evaluated with the aid of spectroscopic, microscopic and energy dispersive X-ray analysis. These nanoparticles detect Hg2+, Pb2+ and Cr3+ with colour change due to inter particle plasmon coupling because of metal-induced aggregation of the nanoparticles.
RAVI GUNUPURU1 2 3 DEBDEEP MAITY1 GAURAV VYAS1 2 PARIMAL PAUL1 2
Volume 135, 2023
Continuous Article Publishing mode
Click here for Editorial Note on CAP Mode