Three-dimensional porous SERS powder for sensitive liquid and gas detections fabricated by engineering dense hot spots on silica aerogel

A three-dimensional porous SERS powder material, Ag nanoparticles-engineered-silica aerogel, was developed. Utilizing an in situ chemical reduction strategy, Ag nanoparticles were densely assembled on porous aerogel structures, thus forming three-dimensional hot spots distribution with intrinsic large specific surface area and high porosity. These features can effectively enrich the analytes on the metal surface and provide huge near field enhancement. Highly sensitive and homogeneous SERS detections were achieved not only on the conventional liquid analytes but also on gas with the enhancement factor up to similar to 10(8) and relative standard deviation as small as similar to 13%. Robust calibration curves were obtained from the SERS data, which demonstrates the potential for the quantification analysis. Moreover, the powder shows extraordinary SERS stability than the conventional Ag nanostructures, which makes long term storage and convenient usage feasible. With all of these advantages, the porous SERS powder material can be extended to on-site SERS nose applications such as liquid and gas detections for chemical analysis, environmental monitoring, and anti-terrorism.

Automated summary

The three-dimensional porous SERS powder material, engineered with Ag nanoparticles on silica aerogel, shows great potential for highly sensitive analyte enrichment and near field enhancement. The material exhibits stable calibration curves, making it suitable for quantitative analysis, and can be utilized for on-site SERS applications in chemical analysis, environmental monitoring, and anti-terrorism.