Ag Nanoparticle-Decorated Mesoporous Silica as a Dual-Mode Raman Sensing Platform for Detection of Volatile Organic Compounds

Abstract

Volatile organic compounds (VOCs) often cause serious harm to human health, environment, and industrial productions. The conventional methods for the detection of VOCs show low sensitivity, are time-consuming, and require laboratory-based analysis. Herein, we realized a portable and multiplex detection of atmospheric VOC species by integrating surface-enhanced Raman spectroscopy (SERS) and cavityenhanced Raman spectroscopy (CERS). The Ag nanoparticledecorated three-dimensional (3D) mesoporous silica gel with a pore size of about 6.5 nm was fabricated and utilized as an ideal SERS detection platform. The plasmonic Ag coated by SiO 2 was characterized as 3D hotspots for enhanced SERS signals, while a mesoporous SiO 2 structure with abundant silicon hydroxyl groups and optical resonance cavity provided the distinctive features for amplifying CERS signals. The enhanced SERS and CERS dual mode easily achieved the rapid, highly sensitive detection of various VOC molecules in situ, as well as superior signal reproducibility (relative standard deviation < 7.2%) and long-term stability. Combined with a portable Raman instrument, the SERS and CERS dual-mode sensor can be implemented for ultratrace detection of multiple toxic VOCs including toluene (68 ppm), benzene (56 ppm), chloroform (129 ppm), and acetone (161 ppm). Thanks to the super sensitivity, the sensor can be extended to the rapid detection of a small change of atmospheric VOC content and the multiplex detection of VOC gaseous mixtures under room temperature. Thus, the designed SERS and CERS dual-mode sensing platform opens a way to ultratrace detection of various toxic VOC gases and is promising in the sensitive monitoring of natural ecosystem conservation and human health.

Applications of surface‐enhanced Raman spectroscopy based on portable Raman spectrometers: A review of recent developments

“…Zhang et al fabricated a SERS sensor by decorating AgNPs on the mesoporous silica gel which can exhibit ultralow detection of VOCs including toluene (68 ppm), benzene (56 ppm), chloroform (129 ppm), and acetone (161 ppm) with a portable Raman spectrometer. [77] Polycyclic aromatic hydrocarbons (PAHs) are well known to be a class of toxic carcinogens that are emitted from wildfires. Li et al prepared a wearable SERS array sensor for on-site environmental PAHs SERS monitoring by sticking Ag/MoS 2 ink on fire-retardant fiber gloves using screen printing with an adhesive agent.…”

“…Zhang et al fabricated a SERS sensor by decorating AgNPs on the mesoporous silica gel which can exhibit ultralow detection of VOCs including toluene (68 ppm), benzene (56 ppm), chloroform (129 ppm), and acetone (161 ppm) with a portable Raman spectrometer. [ 77 ]…”

Highly Pure Gold Nanotriangles with almost 100% Yield for Surface-Enhanced Raman Scattering

“…Due to its unique physicochemical and plasmonic characteristics, gold nanomaterials have been hailed as one of the most promising nanomaterials for various high-technological applications including enhanced optical spectrum, − biosensing, − chemical catalysis, nanomedicine, , and so on. As the most intriguing property of noble-metal nanoparticles (NPs), localized surface plasmon resonances (LSPR) are often generated by the collective oscillation of free electrons in NPs in response to the oscillating electric field of reflected light.…”

Nanomaterial-based surface-enhanced Raman scattering spectroscopy for sensing and diagnostics of gas molecules in environment and healthcare

“…Moreover, the SERS technique has also been used to detect different kinds of toxic gases and VOCs in the breath analysis of human beings as a gas biomarker for the diagnosis of various diseases. 24,[68][69][70][71] For example, recently, Chen et al 24 developed SERS based approach to detect VOCs biomarkers using Au NPs and reduced graphene oxide (GO) nanocomposites in both simulated and real breath samples with ultra-sensitivity and multiplexing. This experiment provides a way to distinguish early gastric cancer (EGC) and advanced gastric cancer (AGC) patients from healthy persons by monitoring the exhaled breath samples from patients.…”