SERS detection of environmental pollutants in humic acid-gold nanoparticle composite materials

摘要

Humic acid ( HA) solutions provide an unexpected medium for direct fabrication of gold nanoparticles ( HA -AuNP)and a clear window for surface-enhanced Raman scattering (SERS) with many potential applications in the ultrasensitive chemical analysis of environmental pollutants. It is demonstrated that the HA - AuNP fabrication can be easily achieved in a wide range of pH ( 2 to 12). The background SERS spectra of HA is relatively weak in absolute intensity, allowing the detection of the enhanced Raman signal from trace amount of contaminants. An in-situ approach is illustrated where the HA - AuNP fabrication is carried out with a HA solution containing the target pollutant. The technique may allow for the direct detection of organic pollutants present in the humic fraction of soil.