Soil contamination by metals is a common problem encountered in many industrialized countries. In this work we present a new approach for heavy metals detection by using surface-enhanced Raman scattering (SERS) spectroscopy. Zn(II) can be clearly determined by SERS in contaminated soil by using 4-(2-pyridylazo) resorcinol (PAR) as chelating molecule for the metal ion. The SERS spectra of PAR, of its metal chelates and of the soil extract-PAR mixture were recorded using a hydroxylamine reduced silver colloid. An excellent match of the PAR-contaminated soil extracts SERS spectrum to the Zn(PAR)2 SERS spectrum can be observed, demonstrating the presence of Zn(II) in the soil probes. Density functional theory (DFT) based calculations were also performed for a reliable assignment of SERS spectra.
Financed by the National Centre for Research and Development under grant No. SP/I/1/77065/10 by the strategic scientific research and experimental development program:
SYNAT - “Interdisciplinary System for Interactive Scientific and Scientific-Technical Information”.