Read by QxMD icon Read


Shivani Sathish, Sébastien G Ricoult, Kazumi Toda-Peters, Amy Q Shen
Microfluidic systems integrated with protein and DNA micro- and nanoarrays have been the most sought-after technologies to satisfy the growing demand for high-throughput disease diagnostics. As the sensitivity of these systems relies on the bio-functionalities of the patterned recognition biomolecules, the primary concern has been to develop simple technologies that enable biomolecule immobilization within microfluidic devices whilst preserving bio-functionalities. To address this concern, we introduce a two-step patterning approach to create micro- and nanoarrays of biomolecules within microfluidic devices...
April 21, 2017: Analyst
N E Dina, H Zhou, A Colniţă, N Leopold, T Szoke-Nagy, C Coman, C Haisch
For the successful treatment of infections, real-time analysis and enhanced multiplex capacity, sensitivity and cost-effectiveness of the developed detection method are critical. In this work, surface-enhanced Raman scattering (SERS) was employed with the final aim of identification and discrimination of pathogenic bacteria, based on their detected SERS fingerprint at the single-cell level. Several genera of bacteria that are found in most of the isolated infections in bacteraemia were successfully identified in less than 5 minutes without the use of antibodies or other specific receptors...
April 21, 2017: Analyst
Hong-Ya Wang, Jin-Liang Ma, Bin-Cheng Yin, Bang-Ce Ye
We have developed a novel method for detecting nicotinamide adenine dinucleotide (NAD(+)) based on fluorescent silver nanoclusters (AgNCs) stabilized by a dumbbell-shaped DNA template containing two cytosine-loops joined in a dsDNA stem. The design involves two types of components: a dumbbell-shaped DNA template and three enzymes. In the presence of NAD(+) as a cofactor, Escherichia coli DNA ligase (E.coli DNA ligase) catalyzes template ligation to generate a sealed (no terminal nucleotides) dumbbell-shaped structure, preventing digestion by exonuclease III (Exo III) and exonuclease I (Exo I)...
April 20, 2017: Analyst
R S Renslow, M J Marshall, A E Tucker, W B Chrisler, X-Y Yu
Biofilms are comprised of microbial cells and an extracellular polymeric substance (EPS) matrix that supports interactions between community members and with the local environment. The highly hydrated EPS matrix makes the application of many biofilm visualization techniques difficult. Hence, to better visualize how biofilms interact with their environment, there is a need for imaging techniques to monitor hydrated state biofilm dynamics. We employed an in situ dynamic approach to construct label-free images of biofilms...
April 20, 2017: Analyst
S Petralia, E L Sciuto, M L Di Pietro, M Zimbone, M G Grimaldi, S Conoci
An innovative chemical strategy integrated in a miniaturized electrochemical device was developed for sensitive detection of a pathogen genome (HBV virus) without any amplification step. The results show a limit of detection comparable to the standard qRT-PCR method (20 copies per reaction), paving the way to future development of genetic PoC devices addressing automatized and low-cost molecular diagnostics.
April 20, 2017: Analyst
Xin Wu, Xuan-Xuan Chen, Yun-Bao Jiang
Reversible covalent binding of boronic acids with polyols and Lewis bases has facilitated the development of robust chemosensors for many biologically important species under physiologically or environmentally relevant conditions. This minireview covers selected examples of advances reported in this area from 2014 to 2016. While the discovery of new boron-containing binding motifs and identification of new analytical targets have expanded the ultility of boronic acid-based molecular recognition, unconventional sensing strategies such as exploitation of nanoscale self-assembly, multicomponent dynamic covalent assembly, and coupling boronate ester formation with a further chemical reaction have led to significantly improved sensor performance, enabling real-world applications in various areas such as cell biology and asymmetric catalysis...
April 20, 2017: Analyst
Aamar F Khan, Dale A C Brownson, Christopher W Foster, Graham C Smith, Craig E Banks
Surfactant exfoliated 2D hexagonal Boron Nitride (2D-hBN) nanosheets are explored as a potential electrochemical sensing platform and evaluated towards the electroanalytical sensing of dopamine (DA) in the presence of the common interferents, ascorbic acid (AA) and uric acid (UA). Surfactant exfoliated 2D-hBN nanosheets (2-4 layers) fabricated using sodium cholate in aqueous media are electrically wired via a drop-casting modification process onto disposable screen-printed graphite electrodes (SPEs). We critically evaluate the performance of these 2D-hBN modified SPEs and demonstrate the effect of 'mass coverage' towards the detection of DA, AA and UA...
April 18, 2017: Analyst
Meghasyam Tummalacherla, Sandilya V B Garimella, Spencer A Prost, Yehia M Ibrahim
The integration of ion mobility spectrometry (IMS) with a trap-based mass spectrometer (MS) such as Orbitrap using the dual gate approach suffers from low duty cycle. Efforts to improve the duty cycle involve the utilization of Hadamard transform-based double multiplexing which significantly improves the signal-to-noise ratio and duty cycle of the ion mobility-Orbitrap mass spectrometry (IM-Orbitrap MS) platform. However, artifacts and noise in the demultiplexed data significantly reduce the data quality and negate the benefits of multiplexing...
April 13, 2017: Analyst
Filip Ciepiela, Krystian Węgiel
A new procedure for standard addition analysis in voltammetry based on the slope of the peak at the inflection point (SSAA) is proposed. It is fully automated and does not require any subjective user decisions. It has been tested for both simulated and experimental data. Experimental data included DPASV measurements of Pb(ii) and Cd(ii) on RAgABE, and Tl(i) on BiABE as a working electrode. In each case the procedure offered good accuracy, precision and perfect reproducibility.
April 13, 2017: Analyst
John J Davenport, Michelle Hickey, Justin P Phillips, Panayiotis A Kyriacou
A fibre optic multi-sensor has been developed for biomedical sensing applications using a tip coating solution sensitive to both oxygen and carbon dioxide. An oxygen sensitive phosphorescence quenching complex based on platinum octaethylporphyrin (PtOEP) was combined with a carbon dioxide sensitive phosphorescence compound based on 8-hydroxypyrene-1,3,6-trisulfonic acid trisodium salt (HPTS). When excited by blue light (470 nm), the resultant coating had two fluorescent peaks at 515 nm (green) and 645 nm (red) which responded to partial pressure of CO2 and O2 respectively...
April 12, 2017: Analyst
Jae-Chul Pyun, Joachim Jose, Min Park
Escherichia coli cells that autodisplay Z-domains have been used to improve the sensitivity and limit of detection (LOD) of immunoassays by controlling antibody orientation. In this study, a rapid, wash-free immunoassay was developed using E. coli cells with autodisplayed Z-domains and flow cytometry. The fluorescence signal from a single E. coli cell could be identified and background noise from non-bound detection antibodies was minimal. Flow cytometric measurement was demonstrated to be more effective than microscopy or fluorescence photometry...
April 12, 2017: Analyst
A J Herrmann, S Techritz, N Jakubowski, A Haase, A Luch, U Panne, L Mueller
High lateral resolution of metal detection in single cells by use of laser ablation inductively coupled plasma mass spectrometry (LA-ICP-MS) demands powerful staining methods. In this work different staining procedures for the single cell analysis with LA-ICP-MS were optimized. An iridium intercalator was utilized to stain the cell nuclei whereas the whole cell was stained by the use of maleimido-mono-amide-DOTA (mDOTA) complexing lanthanide(iii) ions. The content of the artificially introduced metals per cell was quantified using a matrix matched calibration approach based on cellulose membranes onto which standards were spotted by a microarray spotter...
April 11, 2017: Analyst
Dianhua Ning, Changtian He, Zhengjie Liu, Cui Liu, Qilong Wu, TingTing Zhao, Renyong Liu
Human telomerase RNA (hTR), which is one component of telomerase, was deemed to be a biomarker to monitor tumor cells due to its different expression levels in tumor cells and normal somatic cells. Thus far, plentiful fluorescent probes have been designed to investigate nucleic acids. However, most of them are limited since they are time-consuming, require professional operators and even result in false positive signals in the cellular environment. Herein, we report a dual-colored ratiometric-fluorescent oligonucleotide probe to achieve the reliable detection of human telomerase RNA in cell extracts...
April 10, 2017: Analyst
Claire V Crowther, Mark A Hayes
The ability to separate analytes with increasingly similar properties drives the field of separation science. One way to achieve such separations is using trapping and streaming dielectrophoresis (DEP), which directly exploits the subtle differences in the electrophysical properties of analytes. The non-uniform fields necessary for DEP can be formed using various insulator shapes in microchannels. Current insulator shapes include triangles, diamonds, circles, and rectangles. However, all of these insulators pose problems for trapping, streaming, and sorting (deflection) as the induced fields/gradients are not behaviorally consistent across the lateral dimension...
April 10, 2017: Analyst
Qiang Fu, Guang Chen, Yuxia Liu, Ziping Cao, Xianen Zhao, Guoliang Li, Fabiao Yu, Lingxin Chen, Hua Wang, Jinmao You
Homeostasis of ClO(-)/H2S plays a crucial role in the damage and repair of gastric tissue, but has rarely been investigated due to the challenge of in situ analysis in the highly acidic gastric environment. Herein, we designed a new H(+)-activated optical mechanism, involving controllable photoinduced electron transfer (PET) and switch of electron push-pull (SEPP), to develop the simple yet multifunctional probe (Z)-4-(2-benzylidenehydrazinyl)-7-nitrobenzo[c][1,2,5]oxadiazole (BNBD). First, the BNBD probe (Off) was protonated by the highly acidic media to trigger strong fluorescence (On)...
April 10, 2017: Analyst
L Lin, K Mawatari, K Morikawa, Y Pihosh, A Yoshizaki, T Kitamori
Single-cell analysis is of increasing importance in many fields, but is challenging due to the ultra-small volumes (picoliters) of single cells. Indeed, analysis of a specific analyte might require the analysis of a single molecule or several molecules. Analytical processes usually include sampling, chemical processing, and detection. Although several papers have reported chemical processing and detection methods for single cells, a sampling method compatible with maintaining the viability of a single cell during sampling has yet to be developed...
April 10, 2017: Analyst
K L Heileman, M Tabrizian
3-Dimensional cell cultures are more representative of the native environment than traditional cell cultures on flat substrates. As a result, 3-dimensional cell cultures have emerged as a very valuable model environment to study tumorigenesis, organogenesis and tissue regeneration. Many of these models encompass the formation of cell aggregates, which mimic the architecture of tumor and organ tissue. Dielectric impedance spectroscopy is a non-invasive, label free and real time technique, overcoming the drawbacks of established techniques to monitor cell aggregates...
April 10, 2017: Analyst
Daniel Martín-Yerga, Pablo Fanjul-Bolado, David Hernández-Santos, Agustín Costa-García
In this work, we describe the use of a magnetoelectrochemical support for screen-printed electrodes to improve the anodic stripping voltammetry of cadmium due to the generated magnetohydrodynamic (MHD) effect. To create a significant MHD effect, Fe(iii) was added at mM concentrations to the solution. The reduction of Fe(iii) simultaneously with the cadmium deposition on the electrode surface allowed the production of a high cathodic current, which generated a large Lorentz force capable of exerting a convective effect on the solution in the presence of the magnetic field...
April 7, 2017: Analyst
R Bradshaw, N Denison, S Francese
In the study presented here, four examples of crime scene fingermarks analysed by Matrix Assisted Laser Desorption Ionisation Mass Spectrometry Imaging (MALDI MSI), in collaboration with the local Police Force, are reported. These marks are associated to high profile crimes such as drug dealing, murder and harassment. Following the application of forensic enhancement techniques by the CSI or the crime lab, one of the marks could be directly analysed on the surface of deposition and the others were analysed as primary lifts...
April 7, 2017: Analyst
Westley S Bauer, Danielle W Kimmel, Nicholas M Adams, Lauren E Gibson, Thomas F Scherr, Kelly A Richardson, Joseph A Conrad, Hellen K Matakala, Frederick R Haselton, David W Wright
Diagnosis of asymptomatic malaria poses a great challenge to global disease elimination efforts. Healthcare infrastructure in rural settings cannot support existing state-of-the-art tools necessary to diagnose asymptomatic malaria infections. Instead, lateral flow immunoassays (LFAs) are widely used as a diagnostic tool in malaria endemic areas. While LFAs are simple and easy to use, they are unable to detect low levels of parasite infection. We have developed a field deployable Magnetically-enabled Biomarker Extraction And Delivery System (mBEADS) that significantly improves limits of detection for several commercially available LFAs...
April 7, 2017: Analyst
Fetch more papers »
Fetching more papers... Fetching...
Read by QxMD. Sign in or create an account to discover new knowledge that matter to you.
Remove bar
Read by QxMD icon Read

Search Tips

Use Boolean operators: AND/OR

diabetic AND foot
diabetes OR diabetic

Exclude a word using the 'minus' sign

Virchow -triad

Use Parentheses

water AND (cup OR glass)

Add an asterisk (*) at end of a word to include word stems

Neuro* will search for Neurology, Neuroscientist, Neurological, and so on

Use quotes to search for an exact phrase

"primary prevention of cancer"
(heart or cardiac or cardio*) AND arrest -"American Heart Association"