Multilayer Gold-Silver Bimetallic Nanostructures to Enhance SERS Detection of Drugs

Abstract

Surface-enhanced Raman scattering (SERS) is a widely used technique for drug detection due to high sensitivity and molecular specificity. The applicability and selectivity of SERS in the detection of specific drug molecules can be improved by gathering information on the specific interactions occurring between the molecule and the metal surface. In this work, multilayer gold-silver bimetallic nanorods (Au@Ag@AuNRs) have been prepared and used as platforms for SERS detection of specific drugs (namely promethazine, piroxicam, furosemide and diclofenac). The analysis of SERS spectra provided accurate information on the molecular location upon binding and gave some insight into molecule-surface interactions and selectivity in drug detection through SERS.

Classification of Preeclamptic Placental Extracellular Vesicles Using Femtosecond Laser Fabricated Nanoplasmonic Sensors

“…For this standard enhancement factor calculation, the maximum peak height at 1358 cm –1 of R6G SERS spectra with a concentration 10 –8 M was compared to the maximum height of the same peak of highly concentrated R6G (10 –2 M) on a bare silicon wafer (SI Figure 2). This demonstrates the high sensitivity of the fabricated SERS, as all the R6G bands are clearly observable even at a concentration of 10 –8 M. There is also a clear quantitative relationship between R6G concentration and the amplitude of the signal, meaning that with proper calibration, it could potentially be used to obtain concentration information on the sample from the acquired SERS spectra alone.…”

Composite Structure Based on Gold-Nanoparticle Layer and HMM for Surface-Enhanced Raman Spectroscopy Analysis

“…Figure 5b shows the Raman signal intensity of the characteristic peak 612 cm −1 in the different periods. The peak at 612 cm −1 is a Raman-characteristic peak with high enhancement, which can reflect a good interaction between the probe molecule and the substrate [36]. It can be observed that the increase rate for the Raman signal slowed down as the number of Au/Al 2 O 3 bilayers increased.…”

“…Similarly, the 1617 cm −1 peak of MG could still be observed at the concentration of 10 −8 M, demonstrating that the detection limit of the composite structure of MG was 10 −8 M in magnitude. Figure 7b shows the standard calibration plot of the SERS signal at 1617 cm −1 , while the peak at 1617 cm −1 was also the peak with higher enhancement, which is indicative of an interaction between the probe molecule and the substrate [36]. The intensity was quantitatively changed using the empirical equation for the concentration (Log I = 0.59LogC + 6.94).…”

Green synthesis and characterization of gold-based anisotropic nanostructures using bimetallic nanoparticles as seeds

“…It has been reported that the combination of Ag and Au in anisotropic nanostructures, either as hybrid bimetallic core-shell systems or as alloys, can significantly enhance the surface Raman signal (SERS effect). [41,42]. Such enhancement has been observed with different anisotropic nanostructures, namely rods [41], cubes [43], plates [42] and stars [44].…”