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1.
Biological assays at the single molecule level are crucial to fundamental studies of DNA-protein mechanisms. In order to cater
for high throughput applications, one area of immense research potential is single-molecule bioassays where miniaturized devices
are developed to perform rapid and effective biological reactions and analyses. With the success of various emerging technologies
for engineering miniaturized structures down to the nanoscale level, supported by specialized equipment for detection, many
investigations in the field of life science that were once thought impossible can now be actively explored. In this review,
the significance of downscaling to the single-molecule level is firstly presented in selected examples, with the focus placed
on restriction enzyme assays. To determine the effectiveness of single-molecule restriction enzyme reactions, simple and direct
analytical methods based on DNA stretching have often been reliably employed. DNA stretching can be realized based on a number
of working principles related to the physical forces exerted on the DNA samples. We then discuss two examples of a nanochannel
system and a microchamber system where single-molecule restriction enzyme digestion and DNA stretching have been integrated,
which possess prospective capabilities of developing into highly sensitive and high-throughput restriction enzyme assays.
Finally, we take a brief look at the general trends in technological development in this field by comparing the advantages
and disadvantages of performing assays at bulk, microscale and single-molecule levels.
Figure Minaturization of Restriction Enzyme Assays and DNA Stretching 相似文献
2.
Microchip technology has matured over the years into an important field in which novel technologies are being constantly invented,
and down-sizing and incorporation of already existing methodologies into the microscale is increasing assay performance and
bearing the promise of future total integration for simple, widespread use. One rapidly growing sub-discipline of the microchip
research field is focused around the integration of microchip technology and cell biology. In this review, we recapitulate
progress here at the Kitamori laboratory in direct relation to cell and microchip technologies, and show some examples of
successful integration of the two, going from controlled patterning of cells, on-chip cell culture stimulation, and cardiovascular
systems on a chip, to bio-microdevices integrating cardiovascular cells and microtechnology to create novel biodevices such
as biocompatible, miniature pumps. 相似文献
3.
Nicola Di Iorio Simone Crotti Giorgio Bencivenni 《Chemical record (New York, N.Y.)》2019,19(10):2095-2104
The enantioselective synthesis of atropisomers is an emerging field, that in recent years reached fundamental results and put the bases for innovative applications. Organocatalysis is playing a central role in the realization of original synthesis for novel atropisomeric scaffolds.[1] In this short review, we would like to highlight the results obtained by our group and others in the field of axially enantioselective desymmetrization reactions using organocatalysis as main strategy. 相似文献
4.
5.
This paper summarizes the features and performances of optical detection systems currently applied in order to monitor separations
on microchip devices. Fluorescence detection, which delivers very high sensitivity and selectivity, is still the most widely
applied method of detection. Instruments utilizing laser-induced fluorescence (LIF) and lamp-based fluorescence along with
recent applications of light-emitting diodes (LED) as excitation sources are also covered in this paper. Since chemiluminescence
detection can be achieved using extremely simple devices which no longer require light sources and optical components for
focusing and collimation, interesting approaches based on this technique are presented, too. Although UV/vis absorbance is
a detection method that is commonly used in standard desktop electrophoresis and liquid chromatography instruments, it has
not yet reached the same level of popularity for microchip applications. Current applications of UV/vis absorbance detection
to microchip separations and innovative approaches that increase sensitivity are described. This article, which contains 85
references, focuses on developments and applications published within the last three years, points out exciting new approaches,
and provides future perspectives on this field. 相似文献
6.
In this Article, we focus on the in situ observation of photochemical reactions on individual nanoobjects of solid catalysts using single-molecule, single-particle fluorescence spectroscopy. The use of high-resolution imaging techniques with suitable fluorogenic probes enables us to determine the location of the catalytically active sites that are related to the structural heterogeneities on the surface of the solid catalyst and the temporal fluctuation of photochemical reactivity. Furthermore, we present the real-time observation of metastable gold nanoclusters in polymer matrices at the single-cluster level. This Article encourages readers to explore the nanoworld in terms of practical applications in many fields such as fundamental physics and chemistry. 相似文献
7.
Many human activities and cellular functions depend upon precise pH values, and pH monitoring is considered a fundamental task. Colorimetric and fluorescence sensors for pH measurements are chemical and biochemical tools able to sense protons and produce a visible signal. These pH sensors are gaining widespread attention as non-destructive tools, visible to the human eye, that are capable of a real-time and in-situ response. Optical “visual” sensors are expanding researchers’ interests in many chemical contexts and are routinely used for biological, environmental, and medical applications. In this review we provide an overview of trending colorimetric, fluorescent, or dual-mode responsive visual pH sensors. These sensors include molecular synthetic organic sensors, metal organic frameworks (MOF), engineered sensing nanomaterials, and bioengineered sensors. We review different typological chemical entities of visual pH sensors, three-dimensional structures, and signaling mechanisms for pH sensing and applications; developed in the past five years. The progression of this review from simple organic molecules to biological macromolecules seeks to benefit beginners and scientists embarking on a project of pH sensing development, who needs background information and a quick update on advances in the field. Lessons learned from these tools will aid pH determination projects and provide new ways of thinking for cell bioimaging or other cutting-edge in vivo applications. 相似文献
8.
In the last one decade or so, a variety of optical experiments have been designed and performed that are capable of exploring down to the regime of single-molecule detection and measurements in all different environments, including solids, surfaces, and liquids. Single-molecule detection in condensed phases has many important chemical and biological applications. A few to list are: rapid DNA sequencing, DNA fragment sizing, medical diagnosis, forensic analysis, understanding of chemical dynamics and mechanisms, etc. Single-molecule spectroscopy allows us to observe the individual molecules hidden in a condensed phase sample, by using a tunable laser light. This technique has the ability to detect and monitor systems with an ultimate sensitivity level of ∼1.66 × 10−24 moles (1/N0). Measurement at the single-molecule level can completely remove the complicacy associated with ensemble-averaged macroscopic measurements. It allows us to construct a frequency histogram of the distribution of values for a parameter of interest following a large number of measurements on many individual molecules. Such a distribution carries much more information than the average value of the parameter obtained from a macroscopic measurement. As there is no ensemble averaging involved, only measurements at the single-molecule level can give an appropriate test for microscopic dynamical theories. Using single-molecule spectroscopy one can, in principle, follow the temporal evolution of any complex reaction path. As the field is still emerging, with newer methodologies of detecting single molecules with improved signal-to-noise ratios, it is expected that many new physical and chemical phenomena will certainly be explored using this technique. In the present article, our endeavor is to give an overview of the different aspects of single-molecule detection, along with some of its important applications in the areas of bioscience and chemical physics. 相似文献
9.
In the field of cell studies, there is a burgeoning trend to further downscale the investigation from a single-cell level to a sub-single-cell level. Subcellular matter is the basic content in cells and correlates with cell heterogeneity. Sub-single cellular studies focus on the subcellular matter in single cells and aim to understand the details and heterogeneity of individual cells in terms of the subcellular matter or even at the single component/vesicle/molecule level. Hence, sub-single cell... 相似文献
10.
Frank N. Crespilho Alexandre J.C. Lanfredi Edson R. Leite Adenilson J. Chiquito 《Electrochemistry communications》2009,11(9):1744-1747
In this work we report the bioelectrochemical study using an individual indium tin oxide (ITO) nanowire (ITO-NW) electrode modified with glucose oxidase enzyme (GOx), in which the enzymatic activity and the biocatalytic activity was evaluated. The main objective is to show that at low overpotential condition, semiconductor NW can be used as an electron donor during biocatalytic process. We demonstrate the possibility of immobilizing an ITO-NW electrode on gold contacts deposited on top of a microchip (oxidized Si wafer). A protective polymer layer containing an aperture over the sample area was photolithographically deposited over the microchip to isolate the metallic contacts. For H2O2 reduction during the biocatalysis at ITO-NWs surface, with η 50 mV, normal linear behavior is not observed and an exponential current is evident, similar to n–p semiconductor junction behavior. These results can open new tools for studying redox enzymes at the single-molecule level, and the device described here is very promising as a candidate for further exploration in bioelectrochemical devices, such as biofuel cells and biosensors. 相似文献
11.
Juliane R. Sempionatto Aida Martin Laura García‐Carmona Abbas Barfidokht Jonas F. Kurniawan Jose R. Moreto Guangda Tang Andrew Shin Xiaofeng Liu Alberto Escarpa Joseph Wang 《Electroanalysis》2019,31(2):239-245
A flexible skin‐mounted microfluidic potentiometric device for simultaneous electrochemical monitoring of sodium and potassium in sweat is presented. The wearable device allows efficient natural sweat pumping to the potentiometric detection chamber, containing solid‐contact ion‐selective Na+ and K+ electrodes, during exercise activity. The fabricated microchip electrolyte‐sensing device displays good analytical performance and addresses sweat mixing and carry‐over issues of early epidermal potentiometric sensors. Such soft skin‐worn microchip platform integrates potentiometric measurement, microfluidic technologies with flexible electronics for real‐time wireless data transmission to mobile devices. The new fully integrated microfluidic electrolyte‐detection device paves the way for practical fitness and health monitoring applications. 相似文献
12.
Carlotta Borgarelli Yvonne E. Klingl Dr. Abril Escamilla-Ayala Prof. Dr. Sebastian Munck Prof. Dr. Ludo Van Den Bosch Prof. Dr. Wim M. De Borggraeve Dr. Ermal Ismalaj 《Chemistry (Weinheim an der Bergstrasse, Germany)》2021,27(34):8605-8641
Despite the fact that transmembrane proteins represent the main therapeutic targets for decades, complete and in-depth knowledge about their biochemical and pharmacological profiling is not fully available. In this regard, target-tailored small-molecule fluorescent ligands are a viable approach to fill in the missing pieces of the puzzle. Such tools, coupled with the ability of high-precision optical techniques to image with an unprecedented resolution at a single-molecule level, helped unraveling many of the conundrums related to plasma proteins’ life-cycle and druggability. Herein, we review the recent progress made during the last two decades in fluorescent ligand design and potential applications in fluorescence microscopy of voltage-gated ion channels, ligand-gated ion channels and G-coupled protein receptors. 相似文献
13.
Nanomanipulation using near field photonics 总被引:1,自引:0,他引:1
In this article we review the use of near-field photonics for trapping, transport and handling of nanomaterials. While the advantages of traditional optical tweezing are well known at the microscale, direct application of these techniques to the handling of nanoscale materials has proven difficult due to unfavourable scaling of the fundamental physics. Recently a number of research groups have demonstrated how the evanescent fields surrounding photonic structures like photonic waveguides, optical resonators, and plasmonic nanoparticles can be used to greatly enhance optical forces. Here, we introduce some of the most common implementations of these techniques, focusing on those which have relevance to microfluidic or optofluidic applications. Since the field is still relatively nascent, we spend much of the article laying out the fundamental and practical advantages that near field optical manipulation offers over both traditional optical tweezing and other particle handling techniques. In addition we highlight three application areas where these techniques namely could be of interest to the lab-on-a-chip community, namely: single molecule analysis, nanoassembly, and optical chromatography. 相似文献
14.
The discovery and use of fluorescent proteins has revolutionized cellular biology. Despite the widespread use of visible fluorescent
proteins as reporters and sensors in cellular environments the versatile photophysics of fluorescent proteins is still subject
to intense research. Understanding the details of the photophysics of these reporters is essential for accurate interpretation
of the biological and biochemical processes illuminated by fluorescent proteins. Some aspects of the complex photophysics
of fluorescent proteins can only be observed and understood at the single-molecule level, which removes averaging inherent
to ensemble studies. In this paper we review how single-molecule emission detection has helped understanding of the complex
photophysics of fluorescent proteins.
相似文献
Vinod SubramaniamEmail: |
15.
The development of optofluidic-based technology has ushered in a new era of lab-on-a-chip functionality, including miniaturization of biomedical devices, enhanced sensitivity for molecular detection, and multiplexing of optical measurements. While having great potential, optofluidic devices have only begun to be exploited in many biotechnological applications. Here, we highlight the potential of integrating optofluidic devices with synthetic biological systems, which is a field focusing on creating novel cellular systems by engineering synthetic gene and protein networks. First, we review the development of synthetic biology at different length scales, ranging from single-molecule, single-cell, to cellular population. We emphasize light-sensitive synthetic biological systems that would be relevant for the integration with optofluidic devices. Next, we propose several areas for potential applications of optofluidics in synthetic biology. The integration of optofluidics and synthetic biology would have a broad impact on point-of-care diagnostics and biotechnology. 相似文献
16.
Dr. Kais Dhbaibi Maxime Grasser Dr. Haiet Douib Dr. Vincent Dorcet Prof. Olivier Cador Dr. Nicolas Vanthuyne Dr. François Riobé Dr. Olivier Maury Prof. Stéphan Guy Dr. Amina Bensalah-Ledoux Dr. Bruno Baguenard Prof. Geert L. J. A. Rikken Prof. Cyrille Train Dr. Boris Le Guennic Dr. Matteo Atzori Dr. Fabrice Pointillart Dr. Jeanne Crassous 《Angewandte Chemie (International ed. in English)》2023,62(5):e202215558
The combination of physical properties sensitive to molecular chirality in a single system allows the observation of fascinating phenomena such as magneto-chiral dichroism (MChD) and circularly polarized luminescence (CPL) having potential applications for optical data readout and display technology. Homochiral monodimensional coordination polymers of YbIII were designed from a 2,15-bis-ethynyl-hexahelicenic scaffold decorated with two terminal 4-pyridyl units. Thanks to the coordination of the chiral organic chromophore to Yb(hfac)3 units (hfac−=1,1,1,5,5,5-hexafluoroacetylaconate), efficient NIR-CPL activity is observed. Moreover, the specific crystal field around the YbIII induces a strong magnetic anisotropy which leads to a single-molecule magnet (SMM) behaviour and a remarkable room temperature MChD. The MChD-structural correlation is supported by computational investigations. 相似文献
17.
Development of new tools catalyzes progress in biochemical sciences [G.M. Whitesides, E. Ostuni, S. Takayama, X.Y. Jiang, D.E. Ingber, Annual Review of Biomedical Engineering 3 (2001) 335]. Recent advances in micro-/nano-technology have resulted in an explosion of the number of new tools available for biochemical sciences. We have used surface chemistry, nano-structures and microfluidics to create a set of tools applicable for problems ranging from molecular to cellular analysis. These tools will promote the understanding of fundamental problems in cell biology, development and neurobiology, and become useful for real-world applications such as molecular diagnostics, food analysis and environmental monitoring. 相似文献
18.
Herein, we summarize the current status of native fluorescence detection in microchannel electrophoresis, with a strong focus
on chip-based systems. Fluorescence detection is a powerful technique with unsurpassed sensitivity down to the single-molecule
level. Accordingly fluorescence detection is attractive in combination with miniaturised separation techniques. A drawback
is, however, the need to derivatize most analytes prior to analysis. This can often be circumvented by utilising excitation
light in the UV spectral range in order to excite intrinsic fluorescence. As sensitive absorbance detection is challenging
in chip-based systems, deep-UV fluorescence detection is currently one of the most general optical detection techniques in
microchip electrophoresis, which is especially attractive for the detection of unlabelled proteins. This review gives an overview
of research on native fluorescence detection in capillary (CE) and microchip electrophoresis (MCE) between 1998 and 2008.
It discusses material aspects of native fluorescence detection and the instrumentation used, with particular focus on the
detector design. Newer developments, featured techniques, and their prospects in the future are also included. In the last
section, applications in bioanalysis, drug determination, and environmental analysis are reviewed with regard to limits of
detection. 相似文献
19.
Kiichi Sato Akihide Hibara Manabu Tokeshi Hideaki Hisamoto Takehiko Kitamori 《Analytical sciences》2003,19(1):15-22
This review focuses on the integration of chemical and biochemical analysis systems into glass microchips for general use. By combining multiphase laminar flow driven by pressure and micro unit operations, such as mixing, reaction, extraction and separation, continuous-flow chemical processing systems can be realized in the microchip format, while the application of electrophoresis-based chip technology is limited. The performances of several analysis systems were greatly improved by microchip integration because of some characteristics of microspace, i.e., a large specific interface area, a short molecular diffusion time, a small heat capacity and so on. By applying these concepts, several different analysis systems, i.e., wet analysis of cobalt ion, multi-ion sensor, immunoassay, and cellular analysis, were successfully integrated on a microchip. These microchip technologies are promising for meeting the future demands of high-throughput chemical processing. 相似文献
20.
Ian L. Jones Paolo Livi Marta K. Lewandowska Michele Fiscella Branka Roscic Andreas Hierlemann 《Analytical and bioanalytical chemistry》2011,399(7):2313-2329
Planar microelectrode arrays (MEAs) are devices that can be used in biomedical and basic in vitro research to provide extracellular
electrophysiological information about biological systems at high spatial and temporal resolution. Complementary metal oxide
semiconductor (CMOS) is a technology with which MEAs can be produced on a microscale featuring high spatial resolution and
excellent signal-to-noise characteristics. CMOS MEAs are specialized for the analysis of complete electrogenic cellular networks
at the cellular or subcellular level in dissociated cultures, organotypic cultures, and acute tissue slices; they can also
function as biosensors to detect biochemical events. Models of disease or the response of cellular networks to pharmacological
compounds can be studied in vitro, allowing one to investigate pathologies, such as cardiac arrhythmias, memory impairment
due to Alzheimer’s disease, or vision impairment caused by ganglion cell degeneration in the retina. 相似文献