Read by QxMD icon Read


Inga Tijunelyte, Stéphanie Betelu, Jonathan Moreau, Ioannis Ignatiadis, Catherine Berho, Nathalie Lidgi-Guigui, Erwann Guénin, Catalina David, Sébastien Vergnole, Emmanuel Rinnert, Marc Lamy de la Chapelle
Here, we present a surface-enhanced Raman spectroscopy (SERS) nanosensor for environmental pollutants detection. This study was conducted on three polycyclic aromatic hydrocarbons (PAHs): benzo[a]pyrene (BaP), fluoranthene (FL), and naphthalene (NAP). SERS substrates were chemically functionalized using 4-dodecyl benzenediazonium-tetrafluoroborate and SERS analyses were conducted to detect the pollutants alone and in mixtures. Compounds were first measured in water-methanol (9:1 volume ratio) samples. Investigation on solutions containing concentrations ranging from 10(-6) g L(-1) to 10(-3) g L(-1) provided data to plot calibration curves and to determine the performance of the sensor...
May 24, 2017: Sensors
Ngoc D B Le, Gulen Yesilbag Tonga, Rubul Mout, Sung Tae Kim, Marcos E Wille, Subinoy Rana, Karen A Dunphy, D Joseph Jerry, Mahdieh Yazdani, Rajesh Ramanathan, Caren M Rotello, Vincent M Rotello
We report a nanosensor that uses cell lysates to rapidly profile the tumorigenicity of cancer cells. This sensing platform uses host-guest interactions between cucurbit[7]uril (CB[7]) and the cationic headgroup of a gold nanoparticle (AuNP) to non-covalently modify the binding of three fluorescent proteins of a multichannel sensor in situ. This approach doubles the number of output channels to six, providing single-well identification of cell lysates with 100 % accuracy. Significantly, this classification could be extended beyond the training set, determining the invasiveness of novel cell lines...
May 23, 2017: Journal of the American Chemical Society
Oren Gall, Xiahua Zhong, Daniel Schulman, Myungkoo Kang, Ali Razavieh, Theresa Mayer
Nanosensor arrays have recently received significant attention due to their utility in a wide range of applications, including gas sensing, fuel cells, internet of things (IoT), and portable health monitoring systems. Less attention has been given to the production of sensor platforms in the µW range for ultra-low power applications. Here, we discuss how to scale the nanosensor energy demand by developing a process for integration of nanowire sensing arrays on a monolithic CMOS chip. This work demonstrates an off-chip nanowire fabrication method; subsequently nanowires link to a fused SiO2 substrate using electric-field assisted directed assembly...
May 19, 2017: Nanotechnology
Sara Hooshmand, Zarrin Es'haghi
In this research, a novel sensitive electrochemical nanosensor based on the cadmium selenide quantum dots (QDs)/ionic liquid mediated hollow fiber-pencil graphite electrode (HF-PGE) was prepared and applied for simultaneous determination of uric acid (UA) and creatinine (Crn) in urine and serum samples. The electrocatalytic oxidation of the analytes was investigated via differential pulse (DPV) and cyclic voltammetry (CV). The experiments were designed, in two different steps, according to Taguchi's method; OA9 L9 (3(3)) and OA9 L9 (3(4)) orthogonal array to optimize experimental runs...
June 15, 2017: Analytica Chimica Acta
Wengang Zhang, Yong Han, Xiumei Chen, Xueli Luo, Jianlong Wang, Tianli Yue, Zhonghong Li
A Mn-doped ZnS quantum dots (QDs) based nanosensor for selective phosphorescent determination of patulin (PAT) was synthesized with 6-hydroxynicotinic acid (6-HNA) as dummy template via a surface molecular imprinting sol-gel process. FTIR and XRD indicated the successful graft of molecularly imprinted polymer (MIP) onto crystal QDs. Binding tests revealed that the MIP-QDs presented higher selectivity, adsorption capacity and mass transfer rate than non-imprinted polymers, demonstrating a specific recognition for PAT among competitive mycotoxins and its analogues with the imprinting factor of 2...
October 1, 2017: Food Chemistry
Sang-Joon Kim, Seon-Jin Choi, Ji-Soo Jang, Hee-Jin Cho, Il-Doo Kim
As a futuristic diagnosis platform, breath analysis is gaining much attention because it is a noninvasive, simple, and low cost diagnostic method. Very promising clinical applications have been demonstrated for diagnostic purposes by correlation analysis between exhaled breath components and specific diseases. In addition, diverse breath molecules, which serve as biomarkers for specific diseases, are precisely identified by statistical pattern recognition studies. To further improve the accuracy of breath analysis as a diagnostic tool, breath sampling, biomarker sensing, and data analysis should be optimized...
May 8, 2017: Accounts of Chemical Research
Juanhua Yang, Yun Zhang, Lang Zhang, Huili Wang, Jinfang Nie, Zhongxiang Qin, Jiao Li, Wencheng Xiao
This work reports a new colorimetric nanosensor for the detection of heavy-metal ions that initially integrates analyte-triggered autocatalytic amplification with o-phenylenediamine-mediated aggregation of label-free gold nanoparticles. Its utility is well demonstrated with the simple, rapid, sensitive, and specific detection of Hg(2+), Cu(2+), and Ag(+) targets with detection limits less than 3 nM.
May 8, 2017: Chemical Communications: Chem Comm
David R Wilson, Denis Routkevitch, Yuan Rui, Arman Mosenia, Karl J Wahlin, Alfredo Quinones-Hinojosa, Donald J Zack, Jordan J Green
There is a need for new tools to better quantify intracellular delivery barriers in high-throughput and high-content ways. Here, we synthesized a triple-fluorophore-labeled nucleic acid pH nanosensor for measuring intracellular pH of exogenous DNA at specific time points in a high-throughput manner by flow cytometry following non-viral transfection. By including two pH-sensitive fluorophores and one pH-insensitive fluorophore in the nanosensor, detection of pH was possible over the full physiological range...
May 3, 2017: Molecular Therapy: the Journal of the American Society of Gene Therapy
Tang Gao, Xiaozheng Cao, Peng Ge, Jie Dong, Shuqi Yang, Huan Xu, Yong Wu, Feng Gao, Wenbin Zeng
Sulfur dioxide (SO2) is a widely distributed air pollutant, and humans can easily be exposed to sulfite by inhaling SO2, thus inducing respiratory responses and diseases. Hence, to develop a rapid, sensitive and selective method for detection of sulfites is of great importance. Herein, we designed and synthesized a novel tetraphenyl imidazole compound TIBM with aggregation-induced emission enhancement (AIEE). TIBM can self-assemble into well-organized nanoparticles and is reported as an excellent probe for detection of sulfite with high selectivity and sensitivity...
May 23, 2017: Organic & Biomolecular Chemistry
Mahdieh Atighilorestani, Alexandre G Brolo
The electrochemical responses from periodic 6 × 6 arrays of recessed gold nanorings were compared to the 6 × 6 recessed gold nanodiscs arrays. The nanostructured arrays were fabricated by focused ion beam milling and their electrochemical response from a reversible redox pair was obtained. Three-dimensional cyclic voltammetry simulations using COMSOL were performed on 6 × 6 periodic arrays of both recessed nanodiscs and nanorings to elucidate the differences in mass transport between these geometries. Specific mass transport properties near the electroactive surface of the electrodes were elucidated by analyzing the calculated concentration profiles of the redox species...
May 9, 2017: Analytical Chemistry
Mohamed M Elsutohy, Veeren M Chauhan, Robert Markus, Mohammed Aref Kyyaly, Saul J B Tendler, Jonathan W Aylott
Intracellular pH is a key parameter that influences many biochemical and metabolic pathways that can also be used as an indirect marker to monitor metabolic and intracellular processes. Herein, we utilise ratiometric fluorescent pH-sensitive nanosensors with an extended dynamic pH range to measure the intracellular pH of yeast (Saccharomyces cerevisiae) during glucose metabolism in real-time. Ratiometric fluorescent pH-sensitive nanosensors consisting of a polyacrylamide nanoparticle matrix covalently linked to two pH-sensitive fluorophores, Oregon green (OG) and 5(6)carboxyfluorescein (FAM), and a reference pH-insensitive fluorophore, 5(6)carboxytetramethylrhodamine (TAMRA), were synthesised...
May 11, 2017: Nanoscale
Weixuan Zhang, Tong Wu, Rongyao Wang, Xiangdong Zhang
We report here the chiroptical amplification effect occurring in the hybrid systems consisting of chiral molecules and Si nanostructures. Under resonant excitation of circularly polarized light, the hybrid systems show strong CD induction signals at the optical frequency, which arise from both the electric and magnetic responses of the Si nanostructures. More interestingly, the induced CD signals from Si-based dielectric nanoantennas are always larger than that from Au-based plasmonic counterparts. The related physical origin was disclosed...
May 4, 2017: Nanoscale
Gajjala Rajendra Kumar Reddy, P Suresh Kumar
We report on the facile electrodeposition of copper nanostructures on graphite lead substrate using anionic, cationic and non-ionic surfactant templates. Physical and electrochemical characterisation confirmed the influence of templates on the morphology and electrochemical catalytic activities of the copper electrodeposits. These electrodes were shown to be excellent electrocatalyst for the fast detection of hydrogen peroxide. A maximum sensitivity of 951.45μA/mM/cm(2), LOD of 0.43μM, response time of <1s and a linearity in wide range of concentration from 1μM to 5mM were observed when sodium dodecyl sulfate was used as the template...
June 1, 2017: Materials Science & Engineering. C, Materials for Biological Applications
Mohamed Ibrahim Halawa, Wenyue Gao, Muhammad Saqib, Shimeles Addisu Kitte, Fengxia Wu, Guobao Xu
In this work, we designed highly sensitive and selective luminescent detection method for alkaline phosphatase using bovine serum albumin functionalized gold nanoclusters (BSA-AuNCs) as the nanosensor probe and pyridoxal phosphate as the substrate of alkaline phosphatase. We found that pyridoxal phosphate can quench the fluorescence of BSA-AuNCs and pyridoxal has little effect on the fluorescence of BSA-AuNCs. The proposed mechanism of fluorescence quenching by PLP was explored on the basis of data obtained from high-resolution transmission electron microscopy (HRTEM), dynamic light scattering (DLS), UV-vis spectrophotometry, fluorescence spectroscopy, fluorescence decay time measurements and circular dichroism (CD) spectroscopy...
September 15, 2017: Biosensors & Bioelectronics
Cheng-Yi Hong, Shu-Xian Wu, Shi-Hua Li, Hong Liang, Shan Chen, Juan Li, Huang-Hao Yang, Weihong Tan
The development of functional DNA-based nanosensors in living cells has experienced some design challenges, including, for example, poor cellular uptake, rapid nuclease degradation, and high false positives. Herein, we designed selectively permeable poly(methacrylic acid) (PMA) nanocapsules to encapsulate functional DNAs for metal ions and small-molecules sensing in living cells. Since functional DNAs are concentrated in the nanocapsules, an increasing reaction rate is obtained in vitro. During endocytosis, polymeric capsules simultaneously improve cellular uptake of functional DNAs and preserve their structural integrity inside the confined capsule space...
April 25, 2017: Analytical Chemistry
Mathias Dimde, Fitsum Feleke Sahle, Virginia Wycisk, Dirk Steinhilber, Luis Cuellar Camacho, Kai Licha, Jürgen Lademann, Rainer Haag
In the present study, a pH responsive dendritic polyglycerol nanogel (dPG-NG) is developed to measure the pH values inside the hair follicle (HF) using an ex vivo porcine ear model. The macromolecular precursors are labeled with a pH sensitive indodicarbocyanine dye (pH-IDCC) and a control dye (indocarbocyanine dye: ICC) and crosslinked via a mild and surfactant-free Thiol-Michael reaction using an inverse nanoprecipitation method. With this method, it is possible to prepare tailor-made particles in the range of 100 nm to 1 µm with a narrow polydispersity...
April 10, 2017: Macromolecular Bioscience
Li Zhang, Xiu-Zhi Cheng, Lan Kuang, Ai-Zhen Xu, Ru-Ping Liang, Jian-Ding Qiu
Novel fluorescent DNA quantum dots (QDs) were synthesized by hydrothermal treatment of G-/T-rich ssDNA at relatively low reaction temperature. The obtained DNA QDs demonstrate unique optical properties, maintain the basic structure and biological activities of ssDNA precursors, which makes the DNA QDs able to specifically bind with arsenite, driving the (GT)29 region suffer conformation evolution and form well-ordered assembly rather than random aggregations. We speculate that the strong inter-molecule interaction and efficient stacking of base pairs stiffen the assembly structure, block the nonradiative relaxation channels, populate the radiative decay, and thus making the assembly be highly emissive as a new fluorescence center...
March 30, 2017: Biosensors & Bioelectronics
Nicolò Bontempi, Katie E Chong, Henry W Orton, Isabelle Staude, Duk-Yong Choi, Ivano Alessandri, Yuri S Kivshar, Dragomir N Neshev
Biosensing based on nanophotonic structures has shown a great potential for cost-efficient, high-speed and compact personal medical diagnostics. While plasmonic nanosensors offer high sensitivity, their intrinsically restricted resonance quality factors and strong heating due to metal absorption impose severe limitations on real life applications. Here, we demonstrate an all-dielectric sensing platform based on silicon nanodisks with strong optically-induced magnetic resonances, which are able to detect a concentration of streptavidin of as low as 10(-10) M (mol L(-1)) or 5 ng mL(-1), thus pushing the current detection limit by at least two orders of magnitudes...
April 6, 2017: Nanoscale
Miguel A Soler, Sara Fortuna
The design of responsive nanosensors typically relies on the availability of probes capable of capturing their target with high affinity and specificity. This can be achieved by coupling two or more binding units through a linker. In this work, we study the dependence on the binder architecture of the binding affinity between a target molecule and a semirigid bidentate binder. Using two different binder architectures, central-rigid and extreme-rigid, and modifying the length and the flexibility degree of the linker we generated 153 different architectures...
April 13, 2017: Journal of Physical Chemistry. B
Daniel Meyer, Annika Hagemann, Sebastian Kruss
Fluorescent nanosensors are powerful tools for basic research and bioanalytical applications. Individual nanosensors are able to detect single molecules, while ensembles of nanosensors can be used to measure the bulk concentration of an analyte. Collective imaging of multiple nanosensors could provide both spatial and temporal chemical information from the nano- to the microscale. This type of chemical imaging with nanosensors would be very attractive to study processes such as chemical signaling between cells (e...
April 25, 2017: ACS Nano
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"