Detection of Copper(II) Ions Using Glycine on Hydrazine-Adsorbed Gold Nanoparticles via Raman Spectroscopy

초록

A facile, selective, and sensitive detection method for the Cu2+ ions in environmental and biological solutions has been newly developed by observing the unique CN stretching peaks at similar to 2108 cm(-1) upon the dissociative adsorption of glycine (GLY) in hydrazine buffer on gold nanoparticles (AuNPs). The relative abundance of Cu species on AuNPs was identified from X-ray photoelectron spectroscopy analysis. UV-Vis spectra also indicated that the Au particles aggregated to result in the color change owing to the destabilization induced by the GLY-Cu2+ complex. The CN stretching band at 2108 cm-1 could be observed to indicate the formation of the CN species from GLY on the hydrazine-covered AuNP surfaces. The other ions of Fe3+, Fe2+, Hg2+, mg(2+), mn(2+), Ni2+, Zn2+, Cr3+, Co2+, Cd2+, Pb2+, Ca2+, NH4+, Na+, and K+ at high concentrations of 50 mu M did not produce such spectral changes. The detection limit based on the CN band for the determination of the Cu2+ ion could be estimated to be as low as 500 nM in distilled water and 1 mu M in river water, respectively. We attempted to apply our method to estimate intracellular ion detection in cancer cells for more practical purposes.

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