Ultrasensitive detection of hazardous substances using a SERS platform based on gold-nanostar–silica aerogel nanocomposites

Abstract

A 3D gold nanostar–silica aerogel (AuNS–SA) SERS substrate was successfully fabricated via suspension self-assembly, and its detection performance for various trace organic pollutants was systematically evaluated. In order to obtain the best SERS signal enhancement effect, nanocomposites were prepared by adjusting the ratio of AuNS and SA. Using the optimal substrate, the limit of detection (LOD) for rhodamine 6G reached 10⁻¹⁴ M, with a calculated enhancement factor of 2.92 × 10⁵. In extended applications, the substrate also demonstrated high sensitivity towards crystal violet and thiram, achieving LODs of 10⁻¹⁴ M and 10⁻¹⁰ M, respectively. Notably, the fabricated AuNS–SA substrate maintained high SERS signal stability over a 30-day storage period, indicating its excellent long-term stability and signal reproducibility. These results suggest that the self-assembled nanocomposite holds significant potential for development and application in ultra-sensitive detection of trace environmental pollutants.