From China:The research of high sensitivity enhanced Raman sensing technology in Suzhou Institute of Medical Industry has made progress

Highly sensitive trace gas sensing has important practical significance in environmental pollution research and human volatile organic compounds (VOCs) detection. So far, many analytical techniques have been used for gas detection, but many of them have disadvantages such as high cost, complex operation and time-consuming analysis process. Surface-enhanced Raman scattering (SERS), as a powerful tool for trace molecular detection, can greatly enhance the Raman scattering signal of target molecules by using the surface plasmon resonance and charge transfer effect of the substrate. It has the characteristics of highly sensitive, simple, fast, non-destructive and specific fingerprint recognition, and has advantages in the field of gas sensing.

Recently, Zhang Zhiqiang, a researcher at Suzhou Institute of Biomedical Engineering and Technology, Chinese Academy of Sciences, and Sun Jiaojiao, a doctoral candidate, developed a THREE-DIMENSIONAL ROSE dendritic SERS substrate (BigAuNP/Au/ZnO/P) with ultra-high sensitivity. In this study, the researchers prepared nano-zno (ZnO) -Gold (Au) three-dimensional heterostructures on polyvinylidene fluoride (PVDF) membranes by combining chemical growth and micro-nano processing. The enhancement mechanism lies in the three “hot spots” of AuNPs on adjacent nanorods, adjacent AuNPs on the same nanorods, and the binding point of gold layer and AuNPs. The charge transfer between Au and ZnO generates high-density charge and forms an internal electric field. The chemical enhancement effect of ZnO nanorods was stimulated.

The SERS substrate had a detection limit of 10-13 M for p-mercaptobenzoic acid (P-MBA) molecules, and its enhancement factor was up to 2.27×107, with good homogeneity and repeatability (RSD & LT; 4%). In addition, PVDF membrane is porous, so the filter detection program can be used to improve the collision efficiency of the target analyte and SERS “hot spots”, which is conducive to the efficient enrichment of gas molecules.

Researchers verified the detection performance of this THREE-DIMENSIONAL flexible SERS substrate in gas sensing by taking two volatile organic gases, putrescine and caderamine, as examples. Through the modification of p-MBA sensing monolayer on SERS substrate, the amide reaction was used to selectively capture putrescine and cadshrine, and the highly sensitive quantitative detection of low concentration gas molecules was realized (detection limit of putrescine: 1.26×10-9 M, detection limit of cadshrine: 2.5×10-9 M), which was 2-3 orders higher than the detection limit reported in similar studies, which proved the application potential of this SERS sensor in practical gas sensing.

Used in view of the three dimensional flexible SERS substrate porous characteristics and excellent enhance performance, with the microfluidic devices and portable Raman spectrometer integration, used to build SERS rapid detection system, to realize the aerogel with efficient capture of bacteria, viruses, and pollutant concentration, play to the wiki bottom technical advantages in the field of aerosol high sensitive detection.

Related research results were obtained by Ultrasensitive SERS analysis of liquid and Gaseous putrescine and Cadaverine by a 3D-Rosettelike Nanostructure-decorated flexible Porous Substrate, published in Analytical Chemistry. The research work is supported by the National Natural Science Foundation of China, the Key RESEARCH and development Industry Foresight Project of Jiangsu Province, and the scientific instrument and equipment development project of The Chinese Academy of Sciences.

Paper Link & NBSP;

Based on three-dimensional Rose branch SERS sensor substrate construction method and organic gas molecular detection strategy & NBSP;

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