Flexible SERS substrates for hazardous materials detection: recent advances

Abstract

This article reviews the most recent advances in the development of flexible substrates used as surface-enhanced Raman scattering (SERS) platforms for detecting several hazardous materials (e.g., explosives, pesticides, drugs, and dyes). Different flexible platforms such as papers/filter papers, fabrics, polymer nanofibers, and cellulose fibers have been investigated over the last few years and their SERS efficacies have been evaluated. We start with an introduction of the importance of hazardous materials trace detection followed by a summary of different SERS methodologies with particular attention on flexible substrates and their advantages over the nanostructures and nanoparticle-based solid/hybrid substrates. The potential of flexible SERS substrates, in conjunction with a simple portable Raman spectrometer, is the power to enable practical/on-field/point of interest applications primarily because of their low-cost and easy sampling.

Picosecond Bessel Beam Fabricated Pure, Gold-Coated Silver Nanostructures for Trace-Level Sensing of Multiple Explosives and Hazardous Molecules

“…In case of MB, skeletal deformation of C-N-C can be attributed as the reason for 448 cm −1 Raman peak and ring stretching of C-C is accountable for 1623 cm −1 peak [75,76]. The peak assignments corresponding to different molecular/bond activities is demonstrated for all these molecules and matched well with those presented in the previous reports from our group [75][76][77][78][79][80]. Succeeding the concentration varied study, to produce a survey on the SERS signal homogeneity, an advantageous parameter for real-time detection, relative standard deviation (RSD) of the enhanced Raman signal was estimated by collecting the signal from 30-40 random spots.…”

“…For the molecules of thiram, PA, MB we have obtained the highest EFs and smallest LODs among a horde of substrates [40][41][42][43][44][45][46][47][48][49]68,69,[79][80][81][82][83] investigated by our group in the last 10 years.…”

Highly Sensitive Flexible SERS-Based Sensing Platform for Detection of COVID-19

“…SERS is a surface-spectroscopy method, and it is obvious that the surface properties of the flexible substrate play an important role. Surface roughness is an important and crucial factor in SERS experiments and increases the surface sensitivity, resulting in an inelastic scattering of light [ 69 ], because at low concentrations it is limited by the inherent strength of the signals from the molecules SERS. However, in situations where the molecules are bound to the flexible substrate by direct contact with the metal, the maximum Raman signal available is limited by the maximum number of molecules in that layer.…”

3D printing of nanowrinkled architectures via laser direct assembly

“…Diverse wrinkle patterns have been constructed and have exhibited extraordinary properties for anticounterfeiting ( 20 , 21 ), flexible sensors ( 22 , 23 ), and tissue engineering applications ( 24 , 25 ). In addition to these wrinkles on planar surfaces, the ongoing technical evolution for advanced applications, such as artificial organ 3D printing ( 26 , 27 ), ultrasensitive detectors ( 28 , 29 ), or ultrahigh-capacity energy storage devices ( 30 ) with large surface-to-volume ratios, all call for the extension of wrinkled structures from 2D space to higher dimensionality ( 31 ), which is expected to further enhance the functionality of devices.…”