Ag Nanoislands Modified Carbon Fiber Nanostructure: A Versatile and Ultrasensitive Surface-Enhanced Raman Scattering Platform for Antiepileptic Drug Detection

Abstract

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.

Plasmon-Free Surface-Enhanced Raman Spectroscopy Using α-Type MoO3 Semiconductor Nanorods with Strong Light Scattering in the Visible Regime

“…The NR sample exhibits an excellent SERS performance over a wide range of R6G concentrations. Four strong Raman peaks of the R6G molecules corresponding to P 1 , P 2 , P 3 , and P 4 were observed at 612, 773, 1363, and 1652 cm –1 , respectively . The α-MoO 3 NR samples exhibited favorable performance in detecting the 10 –8 M R6G solution, achieving an SNR of 15 (Table S2), thus demonstrating the capability for sensitive analyte detection of the substrate.…”

“…Four strong Raman peaks of the R6G molecules corresponding to P 1 , P 2 , P 3 , and P 4 were observed at 612, 773, 1363, and 1652 cm −1 , respectively. 54 The α-MoO 3 NR samples exhibited favorable performance in detecting the 10 −8 M R6G solution, achieving an SNR of 15 (Table S2), thus demonstrating the capability for sensitive analyte detection of the substrate. Even when the R6G concentration was 5 × 10 −9 M, distinguishable Raman signals could be detected (Figure S3).…”