共查询到20条相似文献,搜索用时 31 毫秒
1.
Wang L Fine D Sharma D Torsi L Dodabalapur A 《Analytical and bioanalytical chemistry》2006,384(2):310-321
This article reviews recently published work concerning improved understanding of, and advancements in, organic and polymer
semiconductor vapor-phase chemical sensing. Thin-film transistor sensors ranging in size from hundreds of microns down to
a few nanometers are discussed, with comparisons made of sensing responses recorded at these different channel-length scales.
The vapor-sensing behavior of nanoscale organic transistors is different from that of large-scale devices, because electrical
transport in a nanoscale organic thin-film transistor depends on its morphological structure and interface properties (for
example injection barrier) which could be modulated by delivery of analyte. Materials used in nanoscale devices, for example
nanoparticles, nanotubes, and nanowires, are also briefly summarized in an attempt to introduce other relevant nano-transducers.
相似文献
2.
Semiconductor quantum dots and metal nanoparticles: syntheses,optical properties,and biological applications 总被引:1,自引:0,他引:1
Biju V Itoh T Anas A Sujith A Ishikawa M 《Analytical and bioanalytical chemistry》2008,391(7):2469-2495
We review the syntheses, optical properties, and biological applications of cadmium selenide (CdSe) and cadmium selenide–zinc
sulfide (CdSe–ZnS) quantum dots (QDs) and gold (Au) and silver (Ag) nanoparticles (NPs). Specifically, we selected the syntheses
of QDs and Au and Ag NPs in aqueous and organic phases, size- and shape-dependent photoluminescence (PL) of QDs and plasmon
of metal NPs, and their bioimaging applications. The PL properties of QDs are discussed with reference to their band gap structure
and various electronic transitions, relations of PL and photoactivated PL with surface defects, and blinking of single QDs.
Optical properties of Ag and Au NPs are discussed with reference to their size- and shape-dependent surface plasmon bands,
electron dynamics and relaxation, and surface-enhanced Raman scattering (SERS). The bioimaging applications are discussed
with reference to in vitro and in vivo imaging of live cells, and in vivo imaging of cancers, tumor vasculature, and lymph
nodes. Other aspects of the review are in vivo deep tissue imaging, multiphoton excitation, NIR fluorescence and SERS imaging,
and toxic effects of NPs and their clearance from the body.
Figure Semiconductor quantum dots and metal nanoparticles have extensive applications, e.g., in vitro and in vivo bioimaging
Tamitake Itoh and Abdulaziz Anas contributed equally to this article. 相似文献
3.
Alvarado Tarun Norihiko Hayazawa Satoshi Kawata 《Analytical and bioanalytical chemistry》2009,394(7):1775-1785
Tip-enhanced Raman spectroscopy (TERS), which utilizes the strong localized optical field generated at the apex of a metallic
tip when illuminated, has been shown to successfully probe the vibrational spectrum of today’s and tomorrow’s state-of-the-art
silicon and next-generation semiconductor devices, such as quantum dots. Collecting and analyzing the vibrational spectrum
not only aids in material identification but also provides insight into strain distributions in semiconductors. Here, the
potential of TERS for nanoscale characterization of strain in silicon devices is reviewed. Emphasis will be placed on the
key challenges of obtaining spectroscopic images of strain in actual strained silicon devices.
Figure Figure Concept of Tip Enhanced Raman Spectroscopy (TERS), which utilizes the strong localized optical field generated at the
apex of a metallic tip when illuminated. TERS has been demonstrated to successfully probe the vibrational spectrum of today’s
and tomorrow’s state-of-the-art silicon and next generation semiconductor devices 相似文献
4.
Lee JO So HM Jeon EK Chang H Won K Kim YH 《Analytical and bioanalytical chemistry》2008,390(4):1023-1032
Recent advances in nanotechnology have enabled the development of nanoscale sensors that outperform conventional biosensors.
This review summarizes the nanoscale biosensors that use aptamers as molecular recognition elements. The advantages of aptamers
over antibodies as sensors are highlighted. These advantages are especially apparent with electrical sensors such as electrochemical
sensors or those using field-effect transistors.
Figure Feeling proteins with aptamer-functionalized carbon nanotubes 相似文献
5.
Christopher T. Kingston Yadienka Martínez-Rubí Jingwen Guan Michael Barnes Christine Scriver Ralph E. Sturgeon Benoit Simard 《Analytical and bioanalytical chemistry》2010,396(3):1037-1044
We have successfully applied coupled thermogravimetry, mass spectrometry, and infrared spectroscopy to the quantification
of surface functional groups on single-walled carbon nanotubes. A high-purity single-walled carbon nanotube sample was subjected
to a rapid functionalization reaction that attached butyric acid moieties to the nanotube sidewalls. This sample was then
subjected to thermal analysis under inert desorption conditions. Resultant infrared and mass spectrometric data were easily
utilized to identify the desorption of the butyric acid groups across a narrow temperature range and we were able to calculate
the degree of substitution of the attached acid groups within the nanotube backbone as 1.7 carbon atoms per hundred, in very
good agreement with independent analytical measurements made by inductively coupled plasma optical emission spectrometry (ICP-OES).
The thermal analysis technique was also able to discern the presence of secondary functional moieties on the nanotube samples
that were not accessible by ICP-OES. This work demonstrates the potential of this technique for assessing the presence of
multiple and diverse functional addends on the nanotube sidewalls, beyond just the principal groups targeted by the specific
functionalization reaction.
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6.
Dana Cialla Ronald Siebert Uwe Hübner Robert Möller Henrik Schneidewind Roland Mattheis Jörg Petschulat Andreas Tünnermann Thomas Pertsch Benjamin Dietzek Jürgen Popp 《Analytical and bioanalytical chemistry》2009,394(7):1811-1818
Surface-enhanced Raman scattering (SERS) is a potent tool in bioanalytical science because the technique combines high sensitivity
with molecular specificity. However, the widespread and routine use of SERS in quantitative biomedical diagnostics is limited
by tight requirements on the reproducibility of the noble metal substrates used. To solve this problem, we recently introduced
a novel approach to reproducible SERS substrates. In this contribution, we apply ultrafast time-resolved spectroscopy to investigate
the photo-induced collective charge-carrier dynamics in such substrates, which represents the fundamental origin of the SERS
mechanism. The ultrafast experiments are accompanied by scanning-near field optical microscopy and SERS experiments to correlate
the appearance of plasmon dynamics with the resultant evanescent field distribution and the analytically relevant SERS enhancement.
Figure Ultrafast time-resolved differential absorption spectroscopy combined with scanning near-field optical microscopy (left) and
atomic force microscopy (right) yields insight into the photoinduced charge-carrier dynamics in innovative reproducible SERS-substrates
Dana Cialla and Ronald Siebert contributed equally to this work. 相似文献
7.
The influence of dielectric substrates on the Raman scattering activities of Ag overlayers has been investigated. Materials
with low refractive indices, such as SiO2, SiOx and AlF3, were found to provide suitable supporting platforms for Ag films to give strong surface-enhanced Raman scattering for dye
molecules when illuminated at 488 nm. This finding was then extended to tip-enhanced Raman scattering (TERS). Huge enhancements
of 70–80×, corresponding to net enhancements of >104, were observed for brilliant cresyl blue test analyte when Ag-coated tips made from or precoated with low refractive index
materials were applied. The yield of fabricated tips that significantly enhance the Raman signals was found to be close to
100%. These findings provide crucial steps towards the use of TERS as a robust technique for rapid chemical imaging with nanometer
spatial resolution.
Figure Silver-coated dielectric tips for tip-enhanced Raman scattering (TERS) are capable of more than 10,000-fold enhancement 相似文献
8.
Kevin A. Wepasnick Billy A. Smith Julie L. Bitter D. Howard Fairbrother 《Analytical and bioanalytical chemistry》2010,396(3):1003-1014
To utilize carbon nanotubes (CNTs) in various commercial and scientific applications, the graphene sheets that comprise CNT
surfaces are often modified to tailor properties, such as dispersion. In this article, we provide a critical review of the
techniques used to explore the chemical and structural characteristics of CNTs modified by covalent surface modification strategies
that involve the direct incorporation of specific elements and inorganic or organic functional groups into the graphene sidewalls.
Using examples from the literature, we discuss not only the popular techniques such as TEM, XPS, IR, and Raman spectroscopy
but also more specialized techniques such as chemical derivatization, Boehm titrations, EELS, NEXAFS, TPD, and TGA. The chemical
or structural information provided by each technique discussed, as well as their strengths and limitations. Particular emphasis
is placed on XPS and the application of chemical derivatization in conjunction with XPS to quantify functional groups on CNT
surfaces in situations where spectral deconvolution of XPS lineshapes is ambiguous.
相似文献
9.
Vasiliki Stavyiannoudaki Vicky Vamvakaki Nikos Chaniotakis 《Analytical and bioanalytical chemistry》2009,395(2):429-435
The properties of native and oxidised graphene layered carbon nanofibres are compared, and their utilisation in enzyme biosensor
systems using different immobilisation methods are evaluated. The efficient oxidation of carbon nanofibres with concentrated
H2SO4/HNO3 is confirmed by Raman spectroscopy while the introduction of carboxylic acid groups on the surface of the fibres by titration
studies. The oxidised fibres show enhanced oxidation efficiency to hydrogen peroxide, while at the same time they exhibit
a more efficient and selective interaction with enzymes. The analytical characteristics of biosensor systems based on the
adsorption or covalent immobilisation of the enzyme glucose oxidase on carbon nanofibres are compared. The study reveals that
carbon nanofibres are excellent substrates for enzyme immobilisation allowing the development of highly stable biosensor systems.
Figure Immobilization of proteins on carbon nanofibres 相似文献
10.
Beatriz Fernández Jose Manuel Costa Rosario Pereiro Alfredo Sanz-Medel 《Analytical and bioanalytical chemistry》2010,396(1):15-29
Inorganic mass spectrometry techniques may offer great potential for the characterisation at the nanoscale, because they provide
unique elemental information of great value for a better understanding of processes occurring at nanometre-length dimensions.
Two main groups of techniques are reviewed: those allowing direct solid analysis with spatial resolution capabilities, i.e.
lateral (imaging) and/or in-depth profile, and those for the analysis of liquids containing colloids. In this context, the
present capabilities of widespread elemental mass spectrometry techniques such as laser ablation coupled with inductively
coupled plasma mass spectrometry (ICP-MS), glow discharge mass spectrometry and secondary ion/neutral mass spectrometry are
described and compared through selected examples from various scientific fields. On the other hand, approaches for the characterisation
(i.e. size, composition, presence of impurities, etc.) of colloidal solutions containing nanoparticles by the well-established
ICP-MS technique are described. In this latter case, the capabilities derived from the on-line coupling of separation techniques
such as field-flow fractionation and liquid chromatography with ICP-MS are also assessed. Finally, appealing trends using
ICP-MS for bioassays with biomolecules labelled with nanoparticles are delineated.
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11.
After being treated by mixed acids, single-walled carbon nanotubes (SWNTs) were shortened and had negatively charged groups
on the surface. Positively charged hemoglobin or myoglobin at pH 5.0 was successfully assembled with SWNTs into layer-by-layer
films on solid surfaces, designated as {SWNT/protein}
n
. While only those proteins in the first few bilayers closest to the electrode surface exhibited electroactivity, the {SWNT/protein}
n
films demonstrated a much higher fraction of electroactive proteins and better controllability in film construction compared
with cast films of the proteins and carbon nanotubes. The proteins in the {SWNT/protein}
n
films retained their near-native structure at medium pH. The stable protein film electrode showed good electrocatalytic properties
toward reduction of oxygen and hydrogen peroxide, demonstrating the potential application of the {SWNT/protein}
n
films as a new type of biosensor based on the direct electrochemistry of proteins without using mediators.
Figure Cyclic voltammograms at 0.2 V s−1 in pH 7.0 buffers with different number of bilayers (n) for layer-by-layer {single-walled carbon nanotube/hemoglobin}
n
films. 相似文献
12.
Surface-enhanced Raman scattering for protein detection 总被引:1,自引:0,他引:1
Proteins are essential components of organisms and they participate in every process within cells. The key characteristic
of proteins that allows their diverse functions is their ability to bind other molecules specifically and tightly. With the
development of proteomics, exploring high-efficiency detection methods for large-scale proteins is increasingly important.
In recent years, rapid development of surface-enhanced Raman scattering (SERS)-based biosensors leads to the SERS realm of
applications from chemical analysis to nanostructure characterization and biomedical applications. For proteins, early studies
focused on investigating SERS spectra of individual proteins, and the successful design of nanoparticle probes has promoted
great progress of SERS-based immunoassays. In this review we outline the development of SERS-based methods for proteins with
particular focus on our proposed protein-mediated SERS-active substrates and their applications in label-free and Raman dye-labeled
protein detection.
Figure Protein-mediated SERS-active substrates for protein detection 相似文献
13.
This work is devoted to the EXAFS analysis of nanostructured iron(III) oxide synthesized inside the pore system of mesoporous
carbon CMK-1. A detailed study of the recording, preparation and evaluation of data recorded in fluorescence mode at the iron
K-edge with and without multiple scattering is shown. The results obtained show that the local structure of Fe3+ inside nanostructured iron(III) oxide is different to that of the bulk material. Due to the small particle size, data analysis
is much more difficult and data preparation more complex. Incorporating multiple scattering paths in the Fourier transforms
and back-transforms during data evaluation gives structural insights that cannot be obtained using other spectroscopic methods,
and this technique was used to draw conclusions about the first four coordination spheres of the nanostructured iron(III)
oxide.
相似文献
14.
Rudolf Tuckermann Ljiljana Puskar Mahta Zavabeti Ryo Sekine Don McNaughton 《Analytical and bioanalytical chemistry》2009,394(5):1433-1441
An experimental apparatus combining Raman spectroscopy with acoustic levitation, Raman acoustic levitation spectroscopy (RALS),
is investigated in the field of physical and chemical analytics. Whereas acoustic levitation enables the contactless handling
of microsized samples, Raman spectroscopy offers the advantage of a noninvasive method without complex sample preparation.
After carrying out some systematic tests to probe the sensitivity of the technique to drop size, shape, and position, RALS
has been successfully applied in monitoring sample dilution and preconcentration, evaporation, crystallization, an acid–base
reaction, and analytes in a surface-enhanced Raman spectroscopy colloidal suspension.
Figure We have systematically investigated the analytical potential of Raman spectroscopy of samples in acoustically levitated drops. 相似文献
15.
Biosensors based on carbon nanotubes 总被引:6,自引:0,他引:6
Carbon nanotubes (CNTs) exhibit a unique combination of excellent mechanical, electrical and electrochemical properties, which has stimulated increasing interest in the application of CNTs as components in (bio)sensors. This review highlights various design methodologies for CNT-based biosensors and their employment for the detection of a number of biomolecules. In addition, recent developments in the fields of CNT-based chemiresistors and chemically sensitive field-effect transistors are presented. After a critical discussion of the factors that currently limit the practical use of CNT-based biosensors, the review concludes with an outline of potential future applications for CNTs in biology and medicine.
相似文献
16.
The integration of a range of technologies including microfluidics, surface-enhanced Raman scattering and confocal microspectroscopy
has been successfully used to characterize in situ single living CHO (Chinese hamster ovary) cells with a high degree of spatial (in three dimensions) and temporal (1 s per spectrum) resolution. Following the introduction of a continuous flow of ionomycin, the real time spectral response
from the cell was monitored during the agonist-evoked Ca2+ flux process. The methodology described has the potential to be used for the study of the cellular dynamics of a range of
signalling processes.
Figure Spectral mapping of a single CHO cell 相似文献
17.
Quantum dots (QDs) are inorganic semiconductor nanocrystals that have unique optoelectronic properties responsible for bringing
together multidisciplinary research to impel their potential bioanalytical applications. In recent years, the many remarkable
optical properties of QDs have been combined with the ability to make them increasingly biocompatible and specific to the
target. With this great development, QDs hold particular promise as the next generation of fluorescent probes. This review
describes the developments in functionalizing QDs making use of different bioconjugation and capping approaches. The progress
offered by QDs is evidenced by examples on QD-based biosensing, biolabeling, and delivery of therapeutic agents. In the near
future, QD technology still faces some challenges towards the envisioned broad bioanalytical purposes.
相似文献
18.
19.
Application of surface chemical analysis tools for characterization of nanoparticles 总被引:1,自引:1,他引:0
D. R. Baer D. J. Gaspar P. Nachimuthu S. D. Techane D. G. Castner 《Analytical and bioanalytical chemistry》2010,396(3):983-1002
The important role that surface chemical analysis methods can and should play in the characterization of nanoparticles is
described. The types of information that can be obtained from analysis of nanoparticles using Auger electron spectroscopy
(AES), X-ray photoelectron spectroscopy (XPS), time-of-flight secondary-ion mass spectrometry (TOF-SIMS), low-energy ion scattering
(LEIS), and scanning-probe microscopy (SPM), including scanning tunneling microscopy (STM) and atomic force microscopy (AFM),
are briefly summarized. Examples describing the characterization of engineered nanoparticles are provided. Specific analysis
considerations and issues associated with using surface-analysis methods for the characterization of nanoparticles are discussed
and summarized, with the impact that shape instability, environmentally induced changes, deliberate and accidental coating,
etc., have on nanoparticle properties.
相似文献
20.
Yuanlu Li 《Analytical and bioanalytical chemistry》2009,394(2):637-645
Using the Tsallis distribution, which facilitates the generalization of well-known distributions such as Gaussian and Lorentzian
by varying a non-extensivity parameter q as a model of the individual band to correctly assign overlapping bands and the fractional differentiation as mathematical
tool to help to determine the spectral parameters of the individual band, a new resolution method for the overlapping bands
is presented. According to variation of the maximum and the zero-crossing of the Tsallis distribution at different differential
order, two types of parameter estimators are obtained, which are utilized to calculate the parameters of position, height,
and width of Tsallis distribution. To verify the suggested method, separation of several kinds of overlapping bands simulated
by computer and the experimental infrared spectrum of 1,2-bromofluoroethane have been performed and discussed.
Figure α-Order differentiation of the overlapping band 相似文献