共查询到20条相似文献，搜索用时 15 毫秒
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A label-free approach using plasmonic coupling interference (PCI) nanoprobes for nucleic acid detection using surface-enhanced Raman scattering (SERS) is described. To induce a strong plasmonic coupling effect, a nanonetwork of silver nanoparticles with the Raman label located between adjacent nanoparticles is assembled by Raman-labeled DNA-locked nucleic acid (LNA) duplexes. The PCI method then utilizes specific nucleic acid sequences of interest as competitor elements for the Raman-labeled DNA strands to interfere the formation of nanonetworks in a competitive binding process. As a result, the plasmonic coupling effect induced through the formation of the nanonetworks is significantly diminished, resulting in a reduced SERS signal. The potential of the PCI technique for biomedical applications is illustrated by detecting single-nucleotide polymorphism (SNP) and microRNA sequences involved in breast cancers. The results of this study could lead to the development of nucleic acid diagnostic tools for biomedical diagnostics and biosensing applications using SERS detection. 相似文献
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Dongxing Wang Wenqi Zhu Yizhuo Chu Kenneth B. Crozier 《Advanced materials (Deerfield Beach, Fla.)》2012,24(32):4376-4380
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Carme Catala Bernat Mir‐Simon Xiaotong Feng Celia Cardozo Nicolas Pazos‐Perez Elena Pazos Sara Gmez‐de Pedro Luca Guerrini Alex Soriano Jordi Vila Francec Marco Eduardo Garcia‐Rico Ramon A. Alvarez‐Puebla 《Advanced Materials Technologies》2016,1(8)
Staphylococcus aureus is a common cause of serious infections. One of the main drawbacks in its treatment is the time required for a positive diagnosis, over 24 h, as most methods are still based in bacterial culture. Herein, a microfluidic optical device for the rapid and ultrasensitive quantification of S. aureus in real human fluids is designed. In this approach, the surface‐enhanced Raman scattering (SERS)‐encoded particles, functionalized with either an antibody or an aptamer, form a dense collection of electromagnetic hot spots on the surface of S. aureus. This allows for an exponentially increase of the SERS signal when particles accumulate on the microorganism as compared to their free condition in bulk solution. Quantification is achieved by passing the sample through a microfluidic device with a collection window where a laser interrogates and classifies each of the induced bacteria–nanoparticle aggregates in real time. Further, the advantages of using aptamers versus antibodies as biorecognition elements are extensively investigated. 相似文献
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Junrong Li Kevin M. Koo Yuling Wang Matt Trau 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(50)
The modernized use of nucleic acid (NA) sequences to drive nanostructure self‐assembly has given rise to a new class of designed nanomaterials with controllable plasmonic functionalities for broad surface‐enhanced Raman scattering (SERS)‐based bioanalysis applications. Herein, dual usage of microRNAs (miRNAs) as both valuable cancer biomarkers and direct self‐assembly triggers is identified and capitalized upon for custom‐designed plasmonic nanostructures. Through strict NA hybridization of miRNA targets, Au nanospheres selectively self‐assemble onto hollowed Au/Ag alloy nanocuboids with ideal interparticle distances (≈2.3 nm) for optimal SERS signaling. The intrinsic material properties of the self‐assembled nanostructures further elevate miRNA detection performance via nanozyme catalytic SERS signaling cascades. This enables fM‐level miR‐107 detection limit within a clinically‐relevant range without any molecular target amplification. The miRNA‐triggered nanostructure self‐assembly approach is further applied in clinical patient samples, and showcases the potential of miR‐107 as a non‐invasive prostate cancer diagnostic biomarker. The use of miRNA targets to drive nanostructure self‐assembly holds great promise as a practical tool for miRNA detection in disease applications. 相似文献
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Nanoplasmonics: A Deformable Nanoplasmonic Membrane Reveals Universal Correlations Between Plasmon Resonance and Surface Enhanced Raman Scattering (Adv. Mater. 26/2014) 
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下载免费PDF全文 Minhee Kang Jae‐Jun Kim Young‐Jae Oh Sang‐Gil Park Ki‐Hun Jeong 《Advanced materials (Deerfield Beach, Fla.)》2014,26(26):4509-4509
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Minhee Kang Jae‐Jun Kim Young‐Jae Oh Sang‐Gil Park Ki‐Hun Jeong 《Advanced materials (Deerfield Beach, Fla.)》2014,26(26):4510-4514
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Metallic nanogap structures can support gap surface plasmon modes and strongly concentrate optical fields to enable surface‐enhanced Raman spectroscopy (SERS) for label‐free biochemical analysis down to single molecule level. However, current scalable SERS substrates based on horizontally oriented plasmonic nanogaps still face challenges for accurate sub‐10 nm control of in‐plane nanostructures. Here, we report a new type of scalable high‐performance SERS substrate based on multistack vertically oriented nanogap hotspots in metal–insulator–metal nanolaminated plasmonic crystals. In contrast to horizontally oriented nanogaps, vertically oriented plasmonic nanogaps can be controlled at subnanometer resolution in the multilayered thin‐film deposition process. After a partial etching of dielectric layers, embedded nanogap hotspots in nanolaminated SERS substrates can be exposed to further increase SERS enhancement factors (EFs) by over one order of magnitude from ≈1 × 107 to ≈1.6 × 108. Moreover, oxygen plasma can be used to regenerate clean nanogap hotspots for repeated SERS measurements with maintained high SERS EFs (>1 × 108). Therefore, this work presents a novel out‐of‐plane plasmonic engineering approach to design and manufacture scalable high‐performance reusable SERS substrates for various biochemical analysis applications that prefer high spatial‐temporal resolution and good hotspot uniformity. 相似文献
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Solji Kim Lilin Piao Donghoon Han Beom Jin Kim Taek Dong Chung 《Advanced materials (Deerfield Beach, Fla.)》2013,25(14):2056-2061
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Graphene‐based sheets that possess a unique nanostructure and a variety of fascinating properties are appealing as promising nanoscale building blocks of new composites. Herein, graphene oxide sheets are used as the nanoscale substrates for the formation of silver‐nanoparticle films. These silver‐nanoparticle films assembled on graphene oxide sheets are flexible and can form stable suspensions in aqueous solutions. They can also be easily processed, forming macroscopic films with high reflectivity. Raman signals of graphene oxide in such hybrid films are increased by the attached silver nanoparticles, displaying surface‐enhanced Raman scattering activity. The degree of enhancement can be adjusted by varying the quantity of silver nanoparticles on the graphene oxide sheets. 相似文献
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Miaosi Li Brendan Dyett Haitao Yu Vipul Bansal Xuehua Zhang 《Small (Weinheim an der Bergstrasse, Germany)》2019,15(1)
A universal femtoliter surface droplet‐based platform for direct quantification of trace of hydrophobic compounds in aqueous solutions is presented. Formation and functionalization of femtoliter droplets, concentrating the analyte in the solution, are integrated into a simple fluidic chamber, taking advantage of the long‐term stability, large surface‐to‐volume ratio, and tunable chemical composition of these droplets. In situ quantification of the extracted analytes is achieved by surface‐enhanced Raman scattering (SERS) spectroscopy by nanoparticles on the functionalized droplets. Optimized extraction efficiency and SERS enhancement by tuning droplet composition enable quantitative determination of hydrophobic model compounds of rhodamine 6G, methylene blue, and malachite green with the detection limit of 10?9 to 10?11 m and a large linear range of SERS signal from 10?9 to 10?6 m of the analytes. The approach addresses the current challenges of reproducibility and the lifetime of the substrate in SERS measurements. This novel surface droplet platform combines liquid–liquid extraction and highly sensitive and reproducible SERS detection, providing a promising technique in current chemical analysis related to environment monitoring, biomedical diagnosis, and national security monitoring. 相似文献
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Diatoms are single‐celled algae that biologically fabricate nanostructured silica shells with ordered pore arrays called frustules that resemble a 2D photonic crystal. A monolayer of Pinnularia frustules isolated from cell culture is deposited on a glass substrate and then conformally coated with silver nanoparticles (AgNPs) to serve as a nanostructured thin film for ultrathin layer chromatography (UTLC). Malachite green and Nile red are resolved in toluene mobile phase and the separated analytes are profiled micro‐Raman spectroscopy, where plasmonic AgNPs provide surface‐enhanced Raman scattering (SERS). The AgNP‐diatom frustule monolayer improves SERS detection of malachite green by an average factor of 1.8 ± 0.1 over the plasmonic AgNP layer on glass. Analysis of hot spots on the AgNP‐diatom frustule monolayer reveals that nearly 20% of the SERS active area intensifies the SERS signal at least tenfold over the SERS signal for AgNP on glass. Diatom‐SERS enhancement is attributed to guided‐mode resonances of the Raman laser source, which in turn further enhances the localized surface plasmonic resonance from AgNPs. Overall, the AgNP‐diatom frustule monolayer thin film is a new functional material that uniquely enables separation of analytes by UTLC, quantitative SERS detection of separated analytes, and photonic enhancement of the SERS signals. 相似文献
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Priyanka Dey Tanveer A. Tabish Sara Mosca Francesca Palombo Pavel Matousek Nicholas Stone 《Small (Weinheim an der Bergstrasse, Germany)》2020,16(10)
Optical theranostic applications demand near‐infrared (NIR) localized surface plasmon resonance (LSPR) and maximized electric field at nanosurfaces and nanojunctions, aiding diagnosis via Raman or optoacoustic imaging, and photothermal‐based therapies. To this end, multiple permutations and combinations of plasmonic nanostructures and molecular “glues” or linkers are employed to obtain nanoassemblies, such as nanobranches and core–satellite morphologies. An advanced nanoassembly morphology comprising multiple linear tentacles anchored onto a spherical core is reported here. Importantly, this core‐multi‐tentacle‐nanoassembly (CMT) benefits from numerous plasmonic interactions between multiple 5 nm gold nanoparticles (NPs) forming each tentacle as well as tentacle to core (15 nm) coupling. This results in an intense LSPR across the “biological optical window” of 650?1100 nm. It is shown that the combined interactions are responsible for the broadband LSPR and the intense electric field, otherwise not achievable with core–satellite morphologies. Further the sub 80 nm CMTs boosted NIR‐surface‐enhanced Raman scattering (SERS), with detection of SERS labels at 47 × 10‐9 m , as well as lower toxicity to noncancerous cell lines (human fibroblast Wi38) than observed for cancerous cell lines (human breast cancer MCF7), presents itself as an attractive candidate for use as biomedical theranostics agents. 相似文献
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We report the first attempt of using molecularly imprinted polymers (MIPs) in the shape of nanoparticles that were doped with gold nanoparticles (AuNPs) for surface enhanced Raman scattering (SERS)-based sensing of molecular species.Specifically,AuNPs doped molecularly imprinted nano-spheres (AuNPs@nanoMIPs) were synthesized by one-pot precipitation polymerization using Sudan Ⅳ as the template for the SERS sensing.The AuNPs@nanoMIPs were characterized by various modes of scanning transmission electron microscopy (STEM) that showed the exact location of the AuNPs inside the MIP particles.The effects of Au concentration and solution stirring on the shape and the polydispersity of the particles were studied.Significant enhancement of the Raman signals was observed only when the MIP particles were doped with the AuNPs.The SERS signal improved significantly with increase in the Au concentration inside the AuNPs@nanoMIPs.Selectivity measurements of the Sudan Ⅳ imprinted AuNPs@nanoMIPs carried out with different Sudan derivatives showed high selectivity of the AuNPs-doped MIP particles. 相似文献
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Selective Surface Enhanced Raman Scattering for Quantitative Detection of Lung Cancer Biomarkers in Superparticle@MOF Structure 下载免费PDF全文
下载免费PDF全文 Xuezhi Qiao Bensheng Su Cong Liu Qian Song Dan Luo Guang Mo Tie Wang 《Advanced materials (Deerfield Beach, Fla.)》2018,30(5)
Surface enhanced Raman scattering (SERS) is a trace detection technique that extends even to single molecule detection. Its potential application to the noninvasive recognition of lung malignancies by detecting volatile organic compounds (VOCs) that serve as biomarkers would be a breakthrough in early cancer diagnostics. This application, however, is currently limited by two main factors: (1) most VOC biomarkers exhibit only weak Raman scattering; and (2) the high mobility of gaseous molecules results in a low adsorptivity on solid substrates. To enhance the adsorption of gaseous molecules, a ZIF‐8 layer is coated onto a self‐assembly of gold superparticles (GSPs) in order to slow the flow rate of gaseous biomarkers and depress the exponential decay of the electromagnetic field around the GSP surfaces. Gaseous aldehydes that are released as a result of tumor‐specific tissue composition and metabolism, thereby acting as indicators of lung cancer, are guided onto SERS‐active GSPs substrates through a ZIF‐8 channel. Through a Schiff base reaction with 4‐aminothiophenol pregrafted onto gold GSPs, gaseous aldehydes are captured with a 10 ppb limit of detection, demonstrating tremendous prospects for in vitro diagnoses of early stage lung cancer. 相似文献
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