A Highly Sensitive SERS Platform Based on Silver Nanocubes for the Detection of Ethylparaben in Aquatic Environments

Abstract Ethylparaben (EP), a widely used preservative, is ubiquitous in aquatic environments and poses potential ecological risks. To address this issue, there is an urgent need to develop portable, rapid, and sensitive detection technologies. Hence, this study constructed a surface-enhanced Raman spectroscopy (SERS) method using silver nanocubes (AgNCs) as the active substrate for rapid on-site detection of EP in aquatic environments. By optimizing the particle size of the AgNCs, the localized surface plasmon resonance (LSPR) effect was maximized, generating high-density electromagnetic “hotspots” at the nanocube vertices and interstitial gaps to achieve exceptional SERS signal enhancement. Integrated with a portable Raman spectrometer, this substrate-based method enables a rapid on-site detection within 2 min. It should be noted that the predried SERS substrates are prepared in advance, and the 2 min analytical time solely accounts for sample loading, rapid interaction, and spectral acquisition (with actual Raman exposure taking only 0.5 s). Compared with conventional techniques, this approach demonstrates practical potential for rapid on-site screening. Crucially, this remarkable speed is attained without compromising analytical sensitivity, delivering a reliable lowest experimentally tested concentration of 1.0 mg/L for rapid screening. Meanwhile, this SERS platform exhibits excellent anti-interference capability, reproducibility, and has been successfully applied to the analysis of actual wastewater samples. This study provides an effective and practical technical approach for rapid on-site screening of organic pollutants in wastewater.