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1.
Dr. Peng He Yan Zhang Lijun Liu Wenping Qiao Prof. Shusheng Zhang 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(23):7452-7460
An ultrasensitive surface enhanced Raman scattering (SERS) method has been designed to selectively and sensitively detect lysozyme. The gold chip as the detection substrate, the aptamer‐based target‐triggering cascade multiple cycle amplification, and gold nanoparticles (AuNPs) bio‐barcode Raman probe enhancement on the gold substrate are employed to enhance the SERS signals. The cascade amplification process consists of the nicking enzyme signaling amplification (NESA), the strand displacement amplification (SDA), and the circular‐hairpin‐assisted exponential amplification reaction (HA‐EXPAR). With the involvement of an aptamer‐based probe, two amplification reaction templates, and a Raman probe, the whole circle amplification process is triggered by the target recognition of lysozyme. The products of the upstream cycle (NESA) could act as the “DNA trigger” of the downstream cycle (SDA and circular HA‐EXPAR) to generate further signal amplification, resulting in the immobility of abundant AuNPs Raman probes on the gold substrate. “Hot spots” are produced between the Raman probe and the gold film, leading to significant SERS enhancement. This detection method exhibits excellent specificity and sensitivity towards lysozyme with a detection limit of 1.0×10?15 M . Moreover, the practical determination of lysozyme in human serum demonstrates the feasibility of this SERS approach in the analysis of a variety of biological specimens. 相似文献
2.
Shuang Guo Dr. Yeonju Park Eungyeong Park Dr. Sila Jin Prof. Lei Chen Prof. Young Mee Jung 《Angewandte Chemie (International ed. in English)》2023,62(34):e202306709
π-Conjugated organic semiconductors are promising materials for surface-enhanced Raman scattering (SERS)-active substrates based on the tunability of electronic structures and molecular orbitals. Herein, we investigate the effect of the temperature-mediated resonance-structure transitions of poly(3,4-ethylenedioxythiophene) (PEDOT) in poly(3,4-ethylenedioxythiophene)-poly(styrenesulfonate) (PEDOT : PSS) films on the interactions between substrate and probe molecules, thereby affecting the SERS activity. Absorption spectroscopy and density functional theory calculations show that this effect occurs mainly due to delocalization of the electron distribution in molecular orbitals, effectively promoting the charge transfer between the semiconductor and probe molecules. In this work, we investigate for the first time the effect of electron delocalization in molecular orbitals on SERS activity, which will provide new design ideas for the development of highly sensitive SERS substrates. 相似文献
3.
Huang R Pomin VH Sharp JS 《Journal of the American Society for Mass Spectrometry》2011,22(9):1577-1587
Improved methods for structural analyses of glycosaminoglycans (GAGs) are required to understand their functional roles in
various biological processes. Major challenges in structural characterization of complex GAG oligosaccharides using liquid
chromatography-mass spectrometry (LC-MS) include the accurate determination of the patterns of sulfation due to gas-phase
losses of the sulfate groups upon collisional activation and inefficient on-line separation of positional sulfation isomers
prior to MS/MS analyses. Here, a sequential chemical derivatization procedure including permethylation, desulfation, and acetylation
was demonstrated to enable both on-line LC separation of isomeric mixtures of chondroitin sulfate (CS) oligosaccharides and
accurate determination of sites of sulfation by MS
n
. The derivatized oligosaccharides have sulfate groups replaced with acetyl groups, which are sufficiently stable to survive
MS
n
fragmentation and reflect the original sulfation patterns. A standard reversed-phase LC-MS system with a capillary C18 column
was used for separation, and MS
n
experiments using collision-induced dissociation (CID) were performed. Our results indicate that the combination of this
derivatization strategy and MS
n
methodology enables accurate identification of the sulfation isomers of CS hexasaccharides with either saturated or unsaturated
nonreducing ends. Moreover, derivatized CS hexasaccharide isomer mixtures become separable by LC-MS method due to different
positions of acetyl modifications. 相似文献
4.
Liangbao Yang Liang Ma Guangyu Chen Jinhuai Liu Prof. Zhong‐Qun Tian 《Chemistry (Weinheim an der Bergstrasse, Germany)》2010,16(42):12683-12693
We report herein a method for the ultra‐trace detection of TNT on p‐aminothiophenol‐functionalized silver nanoparticles coated on silver molybdate nanowires based on surface‐enhanced Raman scattering (SERS). The method relies on π‐donor–acceptor interactions between the π‐acceptor TNT and the π‐donor p,p′‐dimercaptoazobenzene (DMAB), with the latter serving to cross‐link the silver nanoparticles deposited on the silver molybdate nanowires. This system presents optimal imprint molecule contours, with the DMAB forming imprint molecule sites that constitute SERS “hot spots”. Anchoring of the TNT analyte at these sites leads to a pronounced intensification of its Raman emission. We demonstrate that TNT concentrations as low as 10?12 M can be accurately detected using the described SERS assay. Most impressively, acting as a new type of SERS substrate, the silver/silver molybdate nanowires complex can yield new silver nanoparticles during the detection process, which makes the Raman signals very stable. A detailed mechanism for the observed SERS intensity change is discussed. Our experiments show that TNT can be detected quickly and accurately with ultra‐high sensitivity, selectivity, reusability, and stability. The results reported herein may not only lead to many applications in SERS techniques, but might also form the basis of a new concept for a molecular imprinting strategy. 相似文献
5.
Dr. Jana Hudecová Dr. Josef Kapitán Prof. Martin Dračínský Pavel Michal Dr. Václav Profant Prof. Petr Bouř 《Chemistry (Weinheim an der Bergstrasse, Germany)》2022,28(59):e202202045
The histidine residue has an exceptional affinity for metals, but solution structure of its complexes are difficult to study. For zinc and nickel complexes, Raman and Raman optical activity (ROA) spectroscopy methods to investigate the link between spectral shapes and the geometry were used. The spectra were recorded and interpreted on the basis of ionic equilibria, molecular dynamics, ab initio molecular dynamics, and density functional theory. For zwitterionic histidine the dominant tautomer was determined by the decomposition of experimental spectra into calculated subspectra. An octahedral structure was found to prevail for the ZnHis2 complex in solution, in contrast to a tetrahedral arrangement in the crystal phase. The solution geometry of NiHis2 is more similar to the octahedral structure found by X-ray. The Raman and ROA structural determinations of metal complexes are dependent on extensive computations, but reveal unique information about the studied systems. 相似文献
6.
《中国化学快报》2023,34(7):107771
In this paper, CuO/TiO2 p-n heterojunction was developed as a new surface enhanced Raman scattering (SERS) substrate to magnify Raman signal of 4-mercaptobenzoic acid (4-MBA) molecule. In the heterojunction-molecule system, CuO as an “electron capsule” can not only offer more electrons to inject into the surface state energy level of TiO2 and consequently bring additional charge transfer, but also improve photogenerated carrier separation efficiency itself due to strong interfacial coupling in the interface of heterojunction, which together boost SERS performance of the heterojunction substrate. As expected, owing to the enhanced charge collection capacity and the improvement of photogenerated carrier separation efficiency derived from internal electric field and strong interface coupling provided in the interface of heterojunction, this substrate exhibits excellent SERS detection sensitivity towards 4-MBA, with a detection limit as low as 1 × 10−10 mol/L and an enhancement factor of 8.87 × 106. 相似文献
7.
Recently, Raman spectroscopy become a popular and potential analytical technique for the analysis of pharmaceuticals as a result of its advancement. The innovation of laser technology, Fourier Transform-Raman spectrometers with charge coupled device (CCD) detectors, ease of sample preparation and handling, mitigation of sub-sampling problems using different geometric laser irradiance patterns and invention of different optical components of Raman spectrometers are contributors of the advancement of Raman spectroscopy. Transmission Raman Spectroscopy is a useful tool in pharmaceutical analysis to address the problems related with sub-sampling in conventional Raman back scattering. More importantly, the development of surface-enhanced Raman scattering (SERS) has been a prominent advancement for Raman spectroscopy to be applied for pharmaceuticals analysis as it avoids the inherent insensitivity and fluorescence problems. As the active pharmaceutical ingredients (APIs) contain aromatic or conjugated domains with strong Raman scattering activity, Raman spectroscopy is an attractive alternative conventional analytical method for pharmaceuticals. Coupling of Raman spectroscopy with separation techniques is also another advancement applied to reduce or avoid possible spectral interferences. Therefore, in this review, transmission Raman spectroscopy, SERS, and SERS coupled with various separation techniques for pharmaceutical analysis are presented. 相似文献
8.
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10.
Surface-enhanced Raman spectroscopy (SERS): progress and trends 总被引:3,自引:0,他引:3
Cialla D März A Böhme R Theil F Weber K Schmitt M Popp J 《Analytical and bioanalytical chemistry》2012,403(1):27-54
11.
Szabó L Herman K Leopold N Buzumurgă C Chiş V 《Spectrochimica acta. Part A, Molecular and biomolecular spectroscopy》2011,79(1):226-231
The surface-enhanced Raman scattering (SERS) spectra of Eriochrome Black T (EBT) and its Cu(II), Fe(III), Mn(II) and Pb(II) complexes were recorded using a hydroxylamine reduced silver colloid. Molecular geometry optimization, molecular electrostatic potential (MEP) distribution and vibrational frequencies calculation were performed at B3LYP/6-31G(d) level of theory for the EBT molecule and its Cu(EBT), Fe(EBT) and Mn(EBT) metal complexes. Differentiation between EBT complexes of Cu(II), Fe(III), Mn(II) and Pb(II) is shown by the SERS spectral features of each complex. 相似文献
12.
基于具有优异表面增强拉曼散射(SERS)性能的石墨烯隔离的金纳米晶(GIAN)能够在水-有机相界面自组装, 待测物分子在有机相中的分配系数较大以及GIAN能够通过π?π相互作用与待测物分子结合的优势, 构建了激光介导的待测物分子的高效富集策略, 进而实现了9,10-双苯乙炔基蒽(BPEA)分子的痕量SERS分析. 所构建的新型待测物分子高效富集策略在一定程度上避免了因“咖啡环效应”带来的信号波动, 有望为复杂体系中痕量待测物的SERS分析提供可靠的平台. 相似文献
13.
Surface-enhanced Raman scattering (SERS) is a powerful technique for analyzing biological samples as it can rapidly and nondestructively
provide chemical and, in some cases, structural information about molecules in aqueous environments. In the Raman scattering
process, both visible and near-infrared (NIR) wavelengths of light can be used to induce polarization of Raman-active molecules,
leading to inelastic light scattering that yields specific molecular vibrational information. The development of surface enhancement
has enabled Raman scattering to be an effective tool for qualitative as well as quantitative measurements with high sensitivity
and specificity. Recent advances have led to many novel applications of SERS for biological analyses, resulting in new insights
for biochemistry and molecular biology, the detection of biological warfare agents, and medical diagnostics for cancer, diabetes,
and other diseases. This trend article highlights many of these recent investigations and provides a brief outlook in order
to assess possible future directions of SERS as a bioanalytical tool. 相似文献
14.
《Spectrochimica Acta Part A: Molecular and Biomolecular Spectroscopy》1993,49(4):589-597
Raman spectroscopic studies of three isomeric pyridinic carboxylic acids, viz. picolinic, nicotinic and iso-nicotinic acid in solid state, in aqueous solution and in silver hydrosol, in the frequency range 900–1750 cm−1, have been made. Assignments of the observed bands have been proposed in relation to the molecular forms present in solid state and in solution. Different degrees of intensity enhancements of the Raman bands in surface-enhanced Raman scattering (SERS) have been observed in all the three isomeric molecules. In iso-nicotinic acid, the intensity enhancement has been found to be minimum. Comparisons of Raman spectra in aqueous solution with those due to SERS in silver sol indicate that picolinic and nicotinic acid adsorb perpendicularly to the sol surface whereas in iso-nicotinic acid it occurs via donation of a π-electron of the aromatic ring, i.e. the plane of the ring lies parallel to the surface of the sol. 相似文献
15.
To explore the mechanisms in Surface‐enhanced Raman Scattering (SERS) measurements, silver nanoparticles (AgNPs) were first prepared by a silver mirror reaction to form different particle sizes and different distributions on glass substrates. After the resulting surfaces were probed with molecules of p‐Amino‐thiophenol (pATP), p‐Nitrothiophenol (pNTP), and p‐Mercaptobenzoic acid (pMBA) individually, the substrates were placed into reaction solutions to grow additional AgNPs. In this way, probe molecules could be trapped between two nanoparticles, possibly having the so‐called “hot spot” effect. To examine the variations of morphologies of AgNPs in each of the steps, the substrates were examined by field‐emission scanning electron microscope (FE‐SEM). The morphologies also were correlated with the SERS signals. Two bands in the SERS spectra of probe molecules were selected as indications of the enhancements from electromagnetic (EM) effect and charge‐transfer (CT). Results indicate that the SERS signals from the EM effect were increased ca. 5 times after growing additional AgNPs on the molecule‐modified AgNPs substrates. The SERS signals from CT effect were increased two orders of magnitude after growing additional AgNPs. The increase of enhancement for molecules between AgNPs was caused mostly by CT effect. Based on the effect of particle size and distribution of the AgNPs, the EM effect was strongly influenced by the particle size of the AgNPs, while the CT effect was less sensitive to the variation of the morphologies of the AgNPs. 相似文献
16.
E. E. Kingston J. H. Beynon T. Ast R. Flammang A. Maquestiau 《Journal of mass spectrometry : JMS》1985,20(9):546-555
The application of a new technique which involves the combination of charge stripping and charge exchange processes has been investigated. Ions are charge-stripped in the second field-free region of a triple-sector mass spectrometer (BEE geometry), and then subjected to a charge exchange reaction in the third field-free region. The resulting charge stripping/charge exchange (CS/CE) spectrum is free from interference, which is otherwise common in charge stripping spectra. Comparisons between charge stripping and CS/CE spectra are made in cases where both kinds of spectra are obtainable. In order to assess the applicability of this new technique to studies of isomeric ion structures, species for which charge stripping spectra have previously been unobtainable have been chosen. CS/CE spectra of [C6H6]+˙, [C6H5]+, [C8H10]+˙ and [C7H7O]+ ions from a variety of precursors are recorded: in most cases, sufficient differences are observed to permit distinction between isomeric structures (or mixtures of structures). Previous studies which have shown that stable doubly charged molecular ions of ethane cannot be formed by the charge stripping technique are confirmed from its CS/CE spectrum. 相似文献
17.
Reliable Quantitative SERS Analysis Facilitated by Core–Shell Nanoparticles with Embedded Internal Standards
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Wei Shen Xuan Lin Prof. Chaoyang Jiang Chaoyu Li Haixin Lin Jingtao Huang Shuo Wang Dr. Guokun Liu Prof. Xiaomei Yan Prof. Qiling Zhong Prof. Bin Ren 《Angewandte Chemie (International ed. in English)》2015,54(25):7308-7312
Quantitative analysis is a great challenge in surface‐enhanced Raman scattering (SERS). Core‐molecule‐shell nanoparticles with two components in the molecular layer, a framework molecule to form the shell, and a probe molecule as a Raman internal standard, were rationally designed for quantitative SERS analysis. The signal of the embedded Raman probe provides effective feedback to correct the fluctuation of samples and measuring conditions. Meanwhile, target molecules with different affinities can be adsorbed onto the shell. The quantitative analysis of target molecules over a large concentration range has been demonstrated with a linear response of the relative SERS intensity versus the surface coverage, which has not been achieved by conventional SERS methods. 相似文献
18.
Nicholas Banahene Dana M. Gepford Kyle J. Biegas Daniel H. Swanson Yen-Pang Hsu Brennan A. Murphy Zachary E. Taylor Irene Lepori Prof. Dr. M. Sloan Siegrist Dr. Andrés Obregón-Henao Prof. Dr. Michael S. Van Nieuwenhze Prof. Dr. Benjamin M. Swarts 《Angewandte Chemie (Weinheim an der Bergstrasse, Germany)》2023,135(2):e202213563
Increasing the speed, specificity, sensitivity, and accessibility of mycobacteria detection tools are important challenges for tuberculosis (TB) research and diagnosis. In this regard, previously reported fluorogenic trehalose analogues have shown potential, but their green-emitting dyes may limit sensitivity and applications in complex settings. Here, we describe a trehalose-based fluorogenic probe featuring a molecular rotor turn-on fluorophore with bright far-red emission (RMR-Tre). RMR-Tre, which exploits the unique biosynthetic enzymes and environment of the mycobacterial outer membrane to achieve fluorescence activation, enables fast, no-wash, low-background fluorescence detection of live mycobacteria. Aided by the red-shifted molecular rotor fluorophore, RMR-Tre exhibited up to a 100-fold enhancement in M. tuberculosis labeling compared to existing fluorogenic trehalose probes. We show that RMR-Tre reports on M. tuberculosis drug resistance in a facile assay, demonstrating its potential as a TB diagnostic tool. 相似文献
19.
Yong Wang Chao Zhou Prof. Wei Wang Dandan Xu Fanyu Zeng Chen Zhan Jiahui Gu Prof. Mingyu Li Prof. Weiwei Zhao Prof. Jiaheng Zhang Prof. Jinhong Guo Dr. Huanhuan Feng Prof. Xing Ma 《Angewandte Chemie (International ed. in English)》2018,57(40):13110-13113
Surface enhanced Raman spectroscopy (SERS) is a powerful optical sensing technique that can detect analytes of extremely low concentrations. However, the presence of enough SERS probes in the detection area and a close contact between analytes and SERS probes are critical for efficient acquisition of a SERS signal. Presented here is a light‐powered micro/nanomotor (MNM) that can serve as an active SERS probe. The matchlike AgNW@SiO2 core–shell structure of the nanomotors work as SERS probes based on the shell‐isolated enhanced Raman mechanism. The AgCl tail serves as photocatalytic nanoengine, providing a self‐propulsion force by light‐induced self‐diffusiophoresis. The phototactic behavior was utilized to achieve enrichment of the nanomotor‐based SERS probes for on‐demand biochemical sensing. The results demonstrate the possibility of using photocatalytic nanomotors as active SERS probes for remote, light‐controlled, and smart biochemical sensing on the micro/nanoscale. 相似文献
20.
Rolling‐Circle Amplification Detection of Thrombin Using Surface‐Enhanced Raman Spectroscopy with Core‐Shell Nanoparticle Probe
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Prof. Dr. Xuemei Li Linlin Wang Dr. Chunxiang Li 《Chemistry (Weinheim an der Bergstrasse, Germany)》2015,21(18):6817-6822
An ultrasensitive surface‐enhanced Raman spectroscopy (SERS) sensor based on rolling‐circle amplification (RCA)‐increased “hot‐spot” was developed for the detection of thrombin. The sensor contains a SERS gold nanoparticle@Raman label@SiO2 core‐shell nanoparticle probe in which the Raman reporter molecules are sandwiched between a gold nanoparticle core and a thin silica shell by a layer‐by‐layer method. Thrombin aptamer sequences were immobilized onto the magnetic beads (MBs) through hybridization with their complementary strand. In the presence of thrombin, the aptamer sequence was released; this allowed the remaining single‐stranded DNA (ssDNA) to act as primer and initiate in situ RCA reaction to produce long ssDNAs. Then, a large number of SERS probes were attached on the long ssDNA templates, causing thousands of SERS probes to be involved in each biomolecular recognition event. This SERS method achieved the detection of thrombin in the range from 1.0×10?12 to 1.0×10?8 M and a detection limit of 4.2×10?13 M , and showed good performance in real serum samples. 相似文献