Surface-enhanced Raman scattering (SERS) spectroscopy: a versatile spectroscopic and analytical technique used in nanoscience and nanotechnology

Sur, Ujjal Kumar Techno-Press 2013 Advances in nano research Vol.1 No.2

Surface-enhanced Raman scattering (SERS) effect deals with the enhancement of the Raman scattering intensity by molecules in the presence of a nanostructured metallic surface. The first observation of surface-enhanced Raman spectra was in 1974, when Fleischmann and his group at the University of Southampton, reported the first high-quality Raman spectra of monolayer-adsorbed pyridine on an electrochemically roughened Ag electrode surface. Over the last thirty years, it has developed into a versatile spectroscopic and analytical technique due to the rapid and explosive progress of nanoscience and nanotechnology. This review article describes the recent development in field of surface-enhanced Raman scattering research, especially fabrication of various SERS active substrates, mechanism of SERS effect and its various applications in both surface sciences and analytical sciences.

RIE 공정으로 제조된 블랙 실리콘(Black Silicon) 층을 사용한 표면 증강 라만 산란 기판 제작

김형주 ( Hyeong Ju Kim ),김봉환 ( Bonghwan Kim ),이동인 ( Dongin Lee ),이봉희 ( Bong-hee Lee ),조찬섭 ( Chanseob Cho ) 한국센서학회 2021 센서학회지 Vol.30 No.4

In this study, Ag was deposited to investigate its applicability as a surface-enhanced Raman scattering substrate after forming a grasstype black silicon structure through maskless reactive ion etching. Grass-structured black silicon with heights of 2 - 7 μm was formed at radio-frequency (RF) power of 150 - 170W. The process pressure was 250mTorr, the O₂/SF₆ gas ratio was 15/37.5, and the processing time was 10 - 20 min. When the processing time was increased by more than 20 min, the self-masking of Si_xO_yF_z did not occur, and the black silicon structure was therefore not formed. Raman response characteristics were measured based on the Ag thickness deposited on a black silicon substrate. As the Ag thickness increased, the characteristic peak intensity increased. When the Ag thickness deposited on the black silicon substrate increased from 40 to 80 nm, the Raman response intensity at a Raman wavelength of 1507 / cm increased from 8.2 × 10³ to 25 × 10³ cps. When the Ag thickness was 150 nm, the increase declined to 30 × 10³ cps and showed a saturation tendency. When the RF power increased from 150 to 170 W, the response intensity at a 1507/cm Raman wavelength slightly increased from 30 × 10³ to 33 × 10³ cps. However, when the RF power was 200 W, the Raman response intensity decreased significantly to 6.2 × 10³ cps.

Effective surface-enhanced Raman scattering of randomly branched gold nano-urchins with Rhodamine 6G as Raman reporters

Seo, Minjung,Ha, Ji Won Elsevier 2018 Microchemical journal Vol.140 No.-

<P><B>Abstract</B></P> <P>Gold nano-urchins (AuNUs) can be effectively used in surface-enhanced Raman scattering (SERS) because of the sharp tips that grow randomly on the surface. However, it is difficult to control the multiple tips of AuNUs given the variation in their number, size, and distance from the core. Furthermore, it is difficult to achieve effective adsorption of Raman probe molecules on the rough and uneven surfaces of AuNUs. Because of these problems, it is doubtful whether they can be effective SERS substrates. Herein, we present a method for effective SERS using branched AuNUs and Rhodamine 6G (R6G) probe molecules at 785nm, close to their localized surface plasmon resonance wavelength. We investigated the effect of several factors on the enhancement of SERS, including binding time, centrifugation speed and time, ratio of AuNUs and probe molecules, and stirring time. The enhancement of SERS was effectively achieved with a set of conditions that included a AuNUs:R6G concentration ratio of 8:1, a binding time of 6–8h, centrifuging for 40min at a relative centrifugal force of 2400, and no stirring during sample preparation. The results provide important information on effective adsorption of R6G Raman probe molecules on the branched and uneven surfaces of AuNUs for effective enhancement of SERS.</P> <P><B>Highlights</B></P> <P> <UL> <LI> We present a method for effective SERS using gold nanourchins and R6G molecules. </LI> <LI> We present the effect of several factors on the SERS enhancement. </LI> <LI> We provide information on effective adsorption of R6G molecules on the nanourchins. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Surface-enhanced Raman scattering of coumarin 343 on silver colloidal nanoparticles

Hussain, S.,Pang, Y. Pergamon 2016 Spectrochimica acta. Part A, Molecular and biomole Vol.166 No.-

<P>Surface-enhanced Raman scattering (SERS) of coumarin 343 (C343) adsorbed on silver colloidal nanoparticles reduced by sodium citrate was investigated and the surface adsorption geometry of C343 on Ag was sought by optimizing C343-Ag complexes for neutral and deprotonated C343 molecules in the DFT simulations. The SERS of C343 showed a number of spectral changes upon solution pH change. We found that deprotonated C343 adsorbs on the Ag nanoparticles through the carboxylate group keeping a perpendicular geometry to the surface. When protonated, the adsorption geometry of C343 is changed into more or less flat to the surface as the cyclic ester group becomes a preferred surface adsorption site. (C) 2016 Elsevier B.V. All rights reserved.</P>

Ultra-high sensitive detection of Exosomal miRNAs based on Surface-Enhanced Raman Scattering

이종욱,심상준 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Recent studies have shown that exosomal miRNAs have an important role in carcinogenesis by targeting cellular growth pathways that enhance intercellular communication and promote metastasis in cancers. Furthermore, miRNAs in exosome are circulating stably in body fluids. As such, exosomal miRNAs have become an ideal and non-invasive biomarker for the early diagnosis and prognosis. Herein, we developed an ultra-high selectivity and sensitivity nanoplasmonic biosensor based on surface-enhanced Raman scattering (SERS) using head-flocked gold nanopillar substrate for the attomolar detection of cancer-derived exosomal miRNA without any amplification step. In addition, this system could discriminate between miRNAs with high sequence similarities, even a single base mismatch. We anticipate that proposed biosensor offers great promise for the precise diagnosis and prognosis of cancer in clinical fields.

Head-flocked Plasmonic Nanopillars Based Surface-enhanced Raman Scattering for Ultra-sensitive and Label-free MiRNA Detection

김우현,심상준,이종욱 한국공업화학회 2018 한국공업화학회 연구논문 초록집 Vol.2018 No.0

Circulating cell-free micro-ribonucleic acids are the most promising biomarkers for cancer diagnosis, which can be used to define relevant subtypes and treatment response. Herein, we developed a label-free, ultra-high sensitivity and selectivity multiplex biosensor using surface- enhanced Raman scattering (SERS) for the detection of specific miRNAs. A reproducible SERS signal was monitored via uniformly fabricated elastic head-flocked gold nanopillars. For multiplex detection, we selected target miRNAs associated with cancer in the metastatic state (miR-10b, miR-21, and miR-373) as model analytes. By using a complementary DNA probe platform and an ultra-high sensitivity plasmonic biosensor, we achieved label-free detection of target miRNAs and evaluated the correlation between the miRNA expression level and the Raman signal intensity. Through this process, we reached femtomolar (fM) detection limits (3.53, 2.17, and 2.16) for miR-10b, miR-21, and miR-373, respectively.

Fabrication of plasmon length-based surface enhanced Raman scattering(SERS) for multi-detection on microfluidic device

전명진,( Nguyen Hung Anh ),심상준 한국공업화학회 2015 한국공업화학회 연구논문 초록집 Vol.2015 No.1

The length of bioreceptors plays an important role in signal enhancement of surface-enhanced Raman scattering (SERS) due to amplification of electromagnetic fields generated by the excitation of localized surface plasmons. Herein, intact antibodies (IgG) and Fab fragments conjugated onto gold nanostar were used to fabricate two kinds of immunosensors for measurement of their SERS signals. Using CA125 as the antigen and Rhodamine-6G (R6G)-conjugated immunogolds, a SERS immunosensor was self-assembled by antigen-antibody interaction. The results showed that the SERS signal from the Fab immunosensor was 2.4 times higher than that of the IgG immunosensor. Furthermore, increased hot-spots by silver atom deposition onto the IgG and Fab immunosensor showed 2.1 and 1.4 times higher signals than before enhancement, respectively. For application, based on the Fab immunosensor, a SERS-compatible microfluidic system was designed for multiplex assays to overcome the drawbacks of conventional assays. This system can measure biological specimens directly from bio fluids instead of using a complex microfluidic device containing separation and detection elements. Four approved biomarkers of breast cancer, including cancer antigen (CA125), HER2, epididymis protein (HE4), and Eotaxin-1, were detected from patient-mimicked serum with limits of 15 fM, 17 fM, 21 fM, and 6.5 fM, respectively. The results indicated that the lengths and geometry of the bioreceptors determined the intensity of SERS signal from the interface and cavity of the sandwich immunosensor. Silver atom deposition at the cavity of the immunosensor increased the SERS signal. Finally, the SERS immunosensor built-in microfluidic system improved the performance of multiplex diagnostics.

Polydiacetylene Coating Immobilized Ligands and Surface-Enhanced Raman Scattering-Embedded Beads for Detection without Label

성보미,함은일,조아라,안재현,김윤희,전봉현 한국공업화학회 2019 한국공업화학회 연구논문 초록집 Vol.2019 No.1

Multiple detection technologies using protein are powerful tools to investigate the potein-protein interaction. Due to the efficiency and convenience, we used embedded beads to perform the experiments. However, effective detection of embedded bead is challenging because it is difficult to bind labeled secondary protein and target protein. In our previous research, polydiacetylene coated surface-enhanced Raman scattering-embedded beads(PDA-SERS beads) were invented and produced an enhanced encoding ability due to their SERS properties and label-free detection from the PDA layer. In this research, we introduced biotin conjugated PDA-SERS beads for detection target protein model (streptavidin) in the PDA-SERS bead system. Biotinconjugated PDA-SERS beads showed high fluorescence intensity by the increasing concentration of streptavidin. This method allows detecting streptavidin with detection limit of 2ⅹ10-8 M throughout the fluorescence intensity without labelling procedure.

라만분광학의 바이오메디컬 응용

정경복 한국물리학회 2017 새물리 Vol.67 No.6

Raman spectroscopy has attracted great interest as a powerful analytical tool that can be used to detect changes in the structure and the composition of biological samples (cells, tissues, biofluids, etc.) at the molecular level. Its high sensitivity and specificity, a small amount of sample preparation, and non- or minimally-invasive use have recently led to an increase in the number of biomedical applications of Raman spectroscopy. This paper reviews the recent biomedical applications of Raman spectroscopy, which are considered to be multi-functional and powerful toolkits for probing the biochemical properties of biomedical samples in medical science. The basic principles of Raman spectroscopy and surface-enhanced Raman scattering (SERS) are briefly introduced. Furthermore, the biomedical applications of Raman spectroscopy, including diagnostic assessment (orthodontic tooth movement), pharmacotherapy (antibiotic effect, cytotoxicity of tissue adhesive), medical device therapy (collagen cross-linking treatment for the restrain of progressive myopia), and finally in-vivo Raman diagnosis, are described. 라만 분광법은 분자수준에서 바이오 샘플 (세포, 조직, 체액 등)의 구조 및 조성 변화를 감지하는데 사용할 수 있는 강력한 분석 도구로써 매우 큰 관심을 모으고 있다. 높은 민감도와 특이성, 적은 양의 샘플준비, 비침습성 방법은 최근 라만 분광학의 바이오메디칼 응용의 증가로 이어졌다. 본 논문에서는 바이오 샘플의 생화학적 특성을 조사하기 위하여 다기능적이고 강력한 툴킷으로 간주되는 라만 분광학의 바이오메디칼 응용을 리뷰하였다. 라만 분광법과 표면증강라만산란 (surface enhanced Raman scattering, SERS)의 기본 원리를 소개하였고, 이를 이용한 바이오메디칼 응용: 진단 (치아교정 과정에서의 치아이동), 약물평가 (항생제 효과, 생체접착제의 세포 독성) 및 의료기기 요법 (근시 억제를 위한 콜라겐 교차 결합 치료), 라만진단 등의 라만분광학의 다양한 바이오메디칼 응용을 논하였다.

Dual-Enhanced Raman Scattering-Based Characterization of Stem Cell Differentiation Using Graphene-Plasmonic Hybrid Nanoarray

Yang, Letao,Lee, Jin-Ho,Rathnam, Christopher,Hou, Yannan,Choi, Jeong-Woo,Lee, Ki-Bum American Chemical Society 2019 NANO LETTERS Vol.19 No.11

<P>Surface-enhanced Raman scattering (SERS) has demonstrated great potential to analyze a variety of bio/chemical molecular interactions within cells in a highly sensitive and selective manner. Despite significant advancements, it remains a critical challenge to ensure high sensitivity and selectivity, while achieving uniform signal enhancement and high reproducibility for quantitative detection of targeted biomarkers within a complex stem cell microenvironment. Herein, we demonstrate an innovative sensing platform, using graphene-coated homogeneous plasmonic metal (Au) nanoarrays, which synergize both electromagnetic mechanism (EM)- and chemical mechanism (CM)-based enhancement. Through the homogeneous plasmonic nanostructures, generated by laser interference lithography (LIL), highly reproducible enhancement of Raman signals could be obtained via a strong and uniform EM. Additionally, the graphene-functionalized surface simultaneously amplifies the Raman signals by an optimized CM, which aligns the energy level of the graphene oxide with the target molecule by tuning its oxidation levels, consequently increasing the sensitivity and accuracy of our sensing system. Using the dual-enhanced Raman scattering from both EM from the homogeneous plasmonic Au nanoarray and CM from the graphene surface, our graphene-Au hybrid nanoarray was successfully utilized to detect as well as quantify a specific biomarker (TuJ1) gene expression levels to characterize neuronal differentiation of human neural stem cells (hNSCs). Collectively, we believe our unique graphene-plasmonic hybrid nanoarray can be extended to a wide range of applications in the development of simple, rapid, and accurate sensing platforms for screening various bio/chemical molecules.</P> [FIG OMISSION]</BR>