Raman Spectroscopy of Di-(2-picolyl)amine on Gold Nanoparticles for Hg (II) Detection

초록

In an effort to develop a spectroscopic mercury ion sensor, the Raman spectral features of di-(2-picolyl)amine (DPA) on gold nanoparticles (AuNPs) were examined in the presence of various ions. The two bands at 1020 and 1060 cm(-1) showed different intensities in the presence of Hg2+, whereas the other ions, Pb2+, Ni2+, NH4+ , Na+, Mn2+, Mg2+, K+, Zn2+, Fe2+, Cd2+, Cu2+, Cr3+, Co2+, Fe3+, and Ca2+ at the same concentrations of 100 mu M did not produce such spectral changes. The band at 1060 cm(-1) became stronger than that at 1020 cm(-1), only for Hg2+. These two bands may correspond to the ring-breathing and trigonal ring-breathing vibration of the two pyridine rings of DPA. The Hg(II) concentration-dependent surface-enhanced Raman scattering (SERS) spectra indicated that the relative intensities of the two bands reversed above 10 mu M. In addition to this noteworthy feature, the bands at 270 cm(-1), which may be ascribed to the Au-N stretching, show much higher intensities in the presence of Hg2+. Our Raman spectral analysis of DPA may be useful to discriminate the Hg2+ ion above 10 mu M using AuNPs on the basis of molecular vibrational spectroscopy.

키워드