Silver Nanoparticle on Alumina Films Tailored for Surface-enhanced Raman Spectroscopy and Detection of Pesticides

Abstract

Silver nanoparticles (AgNPs) have been widely investigated for their ability to enable surface-enhanced Raman scattering for chemical sensing. Despite many advantages of silver over other plasmonic metals, the unwanted reactivity of silver makes long-term substrate stability and quantitative reproducibility in sensing challenging. AgNPs supported on alumina display robust stability against oxidation while remaining labile to photochemical shape control methods. These easily reproduced films can be tailored to absorb light across the visible spectrum depending on user needs and show long-term performance as SERS sensors. Optimization parameters are explored, and these films are showcased as promising chemical sensors for the pesticide thiram with a 96 ppb (m/v) detection limit.

Photoactivated plasmonic nanohybrid fibers with prolonged trapping of excited charge carriers for SERS analysis of biomolecules

“…Moreover, it helps in elucidating the role of alumina in the photogeneration of electron-hole pairs, which potentially play a significant role in the SERS chemical enhancement. 55,56 The differential absorption spectra and the principal kinetics decay plots from AgNPs and Ag-AlNFs are presented in Fig. 4.…”

Hybrid plasmonic metasurface as enhanced Raman hot-spots for pesticide detection at ultralow concentrations

“…Metallic NPs, in fact, can also generate SERS hot spots as colloids, 10 or deposited as films. 11,12 More recently, hybrid metallic nanostructures, from the combination of subwavelength apertures and NPs are gaining interest, and theoretical studies demonstrate their plasmonic resonance potential, 13 and SERS generation. 14 Practical devices have been achieved by tapping NPs atop a closed-ended NHAs, creating an mSERS-active substrate.…”