Aiming at the shortcomings of high cost and time-consumption in traditional liquid chromatography, an effective surface enhanced Raman scattering (SERS)-based trace detection method has been proposed to quantitatively identify the active component of traditional Chinese medicine. In this paper, a high-performance and versatile SERS platform based on Ag nanoparticles (NPs) self-assembly Ag-anodized aluminium (Ag NPs-Ag-AAO) nanoarray was fabricated by controllable physico-chemical preparation technology. The results indicated that the electromagnetic field enhancement effect was sharply strengthened as Ag NPs assembled, and the experimental enhancement factor (EEF) value was calculated to be 1.0083 × 10⁶. This novel Ag NPs-Ag-AAO nanoarray with substantial “hot spots” exhibited high SERS signal reproducibility, with the relative standard deviation (RSD) value at less than 2.23%. More importantly, this SERS platform was applied to detect active component Baicalein in Scutellaria baicalensis, and the limit of detection (LOD) was located at 10 fg/mL. Therefore, this Ag NPs-Ag-AAO nanoarray with high sensitivity, strong Raman signal reproducibility and reliable practicability has broad application prospects in the rapid detection of trace substances in the active components of traditional Chinese medicine and is expected to be popularized.

The recent development of SERS substrates based on irregular nanostructures for directly molecule recognition has aroused increasing attention. By combining the irregular flake-like nanostructures of mantis wings, high SERS performance of Ag nanofilms, and the chemical stability of Au nanoparticles (NPs), an ultra-sensitive and flexible SERS substrate based on Au NPs functionalized Ag nanofilms-mantis wings (Au-Ag-M.w.) hybrid system is successfully fabricated. When 4-aminothiophenol is selected as the probe molecule, the limit of detection (LOD) is as low as 10⁻¹³ M and the relative standard deviation (RSD) is lower than 7.15%. This novel SERS platform exhibits high SERS performance in terms of sensitivity, reproducibility and practicability mainly because there are high-density and multi-level “hot spots” in the appropriate nanogaps. Meanwhile, it also systematically compares the differences of the SERS performance of Cu and Ag decorated M.w. hybrids and how these differences can alter their response. Moreover, the proposed substrate is employed to rapidly detect the pesticide residues on apple peels and the LOD for cypermethrin is estimated at 10⁻¹⁰ mg/mL. Therefore, this novel SERS substrate has great potential in rapid sampling of pesticide residues on real samples and expands the investigation to other natural materials for fabricating various SERS platforms.

A high-efficiency surface-enhanced Raman scattering (SERS) detection method with ultra-high sensitivity has been widely applied in drug component detection to optimize the product quality verification standards. Herein, a controllable strategy of sputtering Ag nanoislands on carbon fiber (C-fiber) via magnetron sputtering technology was proposed to fabricate a versatile Ag-C-fiber SERS active substrate. A wide range of multi-level electromagnetic enhancement “hot spots” distributed on Ag-C-fiber nanostructures can efficiently amplify Raman signals and the experimental enhancement factor (EEF) value was 3.871 × 10⁶. Furthermore, substantial “hot spots” of large-scale distribution guaranteed the superior reproducibility of Raman signal with relative standard deviation (RSD) values less than 12.97%. Limit of detection (LOD) results indicated that when crystal violet (CV) is employed as probe molecule, the LOD was located at 1 × 10⁻¹³ M. By virtue of ultra-sensitivity and good flexibility of the Ag-C-fiber nanotemplate, Raman signals of two kinds of antiepileptic drugs called levetiracetam and sodium valproate were successfully obtained using an SERS-based spectral method. The Ag-C-fiber SERS detection platform demonstrated a good linear response (R² = 0.97486) in sensing sodium valproate concentrations in the range of 1 × 10³ ng/μL⁻¹–1 ng/μL. We believe that this reliable strategy has potential application for trace detection and rapid screening of antiepileptic drugs in the clinic.