Wide Line Surface‐Enhanced Raman Scattering Mapping

Abstract

Surface‐enhanced Raman spectroscopy (SERS)‐based molecular detection at extremely low concentrations often relies on mapping of a SERS substrate. This yields a large number (>1000) of SERS spectra that can improve the limit of detection; however, the signal collection time is a major constraint. In this work, a wide line (WL) laser focusing technique aimed at fast mapping of SERS substrates is presented. The WL technique enables acquisition of thousands of SERS spectra in a few seconds without missing any of the electromagnetic “hot spots” in the illuminated area. In addition, the SERS signal averaging across the line in the WL mode displays extremely high signal‐to‐noise ratios. The advantages of the WL technique for SERS‐based sensing are verified using different analyte molecules, that is, p‐coumaric acid and melamine. Results show that the limit of detection can be improved by one order of magnitude compared to results obtained using a commercial Raman microscope.

Miniaturized Raman spectrometer with real-time spectral and intensity calibration

“…To reduce the cost price, we used consumer-level infrared-optimized imaging detector. The device optics (lasers, lenses and the spectrometer) was customized for the highest throughput (up to 88% from the sample to the detector) and diffraction limited spot size for the best performance [1]. Moreover, miniRaman contains two lasers with wavelengths 660 nm and 785 nm to extend measured spectral range.…”

Ultrasensitive Optical Fingerprinting of Biorelevant Molecules by Means of SERS-Mapping on Nanostructured Metasurfaces

“…In this technique, a series of SERS spectra are measured from all the points of the substrate by sequential scanning using a confocal microscope. This yields many SERS spectra that can improve the limit of detection [56][57][58][59] and take into account all the variants of RS enhancement on the SERS substrate. In spite of the obvious advantage of this technique, its use is not so widespread [60].…”

Utilizing an Automated SERS-Digital Microfluidic System for High-Throughput Detection of Explosives

“…Over the past decade, various sensing methods, including fluorescence, colorimetry, ion mobility spectrometry, mass spectrometry, and electrochemistry, have been explored for detecting explosives. Among them, surface-enhanced Raman scattering (SERS) has garnered considerable attention because of its ultrasensitivity. − It has been widely used in catalytic process monitoring, , biological analysis, , and contamination detection. − With improvements in safety and detection efficiency requirements, devices used to detect high-energy explosives need to possess the characteristics of automation, high throughput, and ultrasensitivity. Recently, we fabricated Ag nanoparticle@PAN-nanohump array films, Ag micropillar/nanopillar arrays, and flexible SiO 2 –TiO 2 –Ag substrates for the ultrasensitive SERS detection of TNT and NTO. − However, nonautomated detection methods are responsible for people’s contact with explosives, causing potential safety hazards.…”