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Tesfaye Tolessa, Zhi-Qiang Tan, Yong-Guang Yin, Jing-Fu Liu
A novel headspace colorimetric nanosensor strategy for specific detection of Hg(II) was developed based upon analyte induced etching and amalgamation of gold nanoparticles (AuNPs). The Hg(II) was first selectively reduced to its volatile form, Hg(0), by stannous chloride (SnCl2) through chemical cold vapor generation (CVG) reaction. Then, the Hg(0) was headspace extracted into 37μL thioglycolic acid functionalized AuNP aqueous suspension containing 10% methanol as extractant and simultaneously reacted with AuNPs through the strong metallophilic Hg-Au interaction, resulting in a red-to-blue color change...
January 1, 2018: Talanta
Asma Verdian
In an effort to achieve high sensitive and selective detection of pesticide residues, numerous nanomaterial-based aptasensors are currently being developed for acetamiprid analysis. Recently, aptamers as a potent alternative of antibodies are used in biosensing platforms. There is tremendous interest in utilizing of nanomaterial as basic building blocks and signaling elements in aptasensors. The nanomaterials have the unique optical and electrical properties. The combination of nanomaterial and aptamer technology has opened a new window in pesticide residues monitoring...
January 1, 2018: Talanta
Xinan Huang, Sohail Anjum Shahzad, Yongxin Li, Yunyi Zhang, Lijia Sang, Huipeng Zhou, Hong Jiang, Kenneth Kam-Wing Lo, Cong Yu
A novel and efficient approach has been established for the synthesis of silver nanoclusters capped silica nanoparticles (SiO2@AgNCs). These nanoclusters (AgNCs) capped silica nanoparticles were utilized as a novel ratiometric photoluminescence (PL) nanosensor for extremely sensitive and selective detection of I(-) and S(2-) ions. The AgNCs were prepared in situ on the silica nanoparticles through polyethyleneimine (PEI) template approach. While dual PL emissions of AgNCs (at 500 nm) and luminescent silica nanoparticles (at 602 nm) formed the basis for the ratiometric sensing...
October 2, 2017: Analytica Chimica Acta
Kavitha Pathakoti, Manjunath Manubolu, Huey-Min Hwang
Recent developments in nanoscience and nanotechnology intend novel and innovative applications in the food sector, which is rather recent compared with their use in biomedical and pharmaceutical applications. Nanostructured materials are having applications in various sectors of the food science comprising nanosensors, new packaging materials, and encapsulated food components. Nanostructured systems in food include polymeric nanoparticles, liposomes, nanoemulsions, and microemulsions. These materials enhance solubility, improve bioavailability, facilitate controlled release, and protect bioactive components during manufacture and storage...
April 2017: Journal of Food and Drug Analysis
Shuaidi Zhang, Ren Geryak, Jeffrey Geldmeier, Sunghan Kim, Vladimir V Tsukruk
The robust, sensitive, and selective detection of targeted biomolecules in their native environment by prospective nanostructures holds much promise for real-time, accurate, and high throughput biosensing. However, in order to be competitive, current biosensor nanotechnologies need significant improvements, especially in specificity, integration, throughput rate, and long-term stability in complex bioenvironments. Advancing biosensing nanotechnologies in chemically "noisy" bioenvironments require careful engineering of nanoscale components that are highly sensitive, biorecognition ligands that are capable of exquisite selective binding, and seamless integration at a level current devices have yet to achieve...
September 13, 2017: Chemical Reviews
J Taylor, J Milton, M Willett, J Wingfield, S Mahajan
Plasmonic nanoparticles (NPs), predominantly gold (AuNPs), are easily internalised into cells and commonly employed as nanosensors for reporter-based and reporter-free intracellular SERS applications. While AuNPs are generally considered non-toxic to cells, many biological and toxicity studies report that exposure to NPs induces cell stress through the generation of reactive oxygen species (ROS) and the upregulated transcription of pro-inflammatory genes, which can result in severe genotoxicity and apoptosis...
September 13, 2017: Faraday Discussions
Félix Lussier, Thibault Brulé, Marie-Josée Bourque, Charles Ducrot, Louis-Éric Trudeau, Jean-François Masson
Current electrophysiology and electrochemistry techniques have provided unprecedented understanding of neuronal activity. However, these techniques are suited to a small, albeit important, panel of neurotransmitters such as glutamate, GABA and dopamine, and these constitute only a subset of the broader range of neurotransmitters involved in brain chemistry. Surface-enhanced Raman scattering (SERS) provides a unique opportunity to detect a broader range of neurotransmitters in close proximity to neurons. Dynamic SERS (D-SERS) nanosensors based on patch-clamp-like nanopipettes decorated with gold nanoraspberries can be located accurately under a microscope using techniques analogous to those used in current electrophysiology or electrochemistry experiments...
September 12, 2017: Faraday Discussions
Sara Hooshmand, Zarrin Es'haghi
A number of four amino acids have been simultaneously determined at CdSe quantum dot-modified/multi-walled carbon nanotube hollow fiber pencil graphite electrode in different bodybuilding supplements. CdSe quantum dots were synthesized and applied to construct a modified carbon nanotube hollow fiber pencil graphite electrode. FT-IR, TEM, XRD and EDAX methods were applied for characterization of the synthesized CdSe QDs. The electro-oxidation of arginine (Arg), alanine (Ala), methionine (Met) and cysteine (Cys) at the surface of the modified electrode was studied...
August 30, 2017: Journal of Pharmaceutical and Biomedical Analysis
Guoxin Rong, Eric H Kim, Kira E Poskanzer, Heather A Clark
Optical nanoparticle (NP)-based sensors have been widely implemented as tools for detection of targeted ions and biomolecules. The NP sensing platform offer a modular design that can incorporate different sensing components for greater target specificity and the ability to tune the dynamic range, as well as encapsulation of multiple dyes to generate a ratiometric signal with varying spectra. Despite these advantages, demonstrating quantitative ion imaging for intracellular measurement still possess a major challenge...
September 7, 2017: Scientific Reports
Hongzhi Guo, Josep Miquel Jornet, Qiaoqiang Gan, Zhi Sun
In the last few decades, the development of miniature biological sensors that can detect and measure different phenomena at the nanoscale has led to transformative disease diagnosis and treatment techniques. Among others, biofunctional Raman nanoparticles have been utilized in vitro and in vivo for multiplexed diagnosis and detection of different biological agents. However, existing solutions require the use of bulky lasers to excite the nanoparticles and similarly bulky and expensive spectrometers to measure the scattered Raman signals, which limit the practicality and applications of this nano-biosensing technique...
September 4, 2017: IEEE Transactions on Nanobioscience
Li-Qiang Lu, Tian Tan, Xi-Ke Tian, Yong Li, Pan Deng
Mercury ions sensing is an important issue for human health and environmental safety. A novel fluorescence nanosensor was designed for rapid visual detection of ultratrace mercury ions (Hg(2+)) by using CH3NH3PbBr3 perovskite quantum dots (QDs) based on the surface ion-exchange mechanism. The synthesized CH3NH3PbBr3 QDs can emitt intense green fluorescence with high quantum yield of 50.28%, and can be applied for Hg(2+) sensing with the detection limit of 0.124 nM (24.87 ppt) in the range of 0 nM-100 nM...
September 15, 2017: Analytica Chimica Acta
Gui-Ming Pan, Da-Jie Yang, Li Zhou, Zhong-Hua Hao, Qu-Quan Wang
We theoretically study the gain-assisted double plasmonic resonances to enhance second harmonic generation (SHG) in a centrosymmetric multilayered silver-dielectric-gold-dielectric (SDGD) nanostructure. Introducing gain media into the dielectric layers can not only compensate the dissipation and lead to giant amplification of surface plasmons (SPs), but also excite local quadrupolar plasmon which can boost SHG by mode matching. Specifically, as the quadrupolar mode dominates SHG in our nanostructure, under the mode matching condition, the intensity of second harmonic near-field can be enhanced by 4...
August 29, 2017: Scientific Reports
Ningning Wang, Xinyan Yu, Ke Zhang, Chad A Mirkin, Jishan Li
By taking advantage of the optical properties of upconversion nanoparticles (UCNPs), we have designed a luminescence ratiometric nanosensor for measuring nitric oxide (NO) in biological fluids, live cells, and tissues. This nanoconjugate consists of a UCNP core with two strong fluorescence emission peaks at 540 and 656 nm as the upconversion fluorophore, NO-reactive rhodamine B-derived molecules (RdMs) encapsulated within the mesopores of the mSiO2 shell, and a β-cyclodextrin (βCD) layer on the exterior of the particle...
September 5, 2017: Journal of the American Chemical Society
Huihui Li, Jin Shen, Rongwei Cui, Chongmei Sun, Yanyan Zhao, Xia Wu, Na Li, Bo Tang
Highly selective determination of dopamine (DA) over other catecholamines is an urgent need for the precise diagnosis and therapy of DA related diseases. Herein, a new formate-bridged Tb(iii)-complex and silver nanoparticles (AgNPs) enhanced fluorescent nanosensor was constructed. HCOO(-) acted as a co-ligand of Tb(iii) and also as a linker between the Tb(iii) complex and AgNPs and more readily combined with the primary amine of DA than with epinephrine (EP). The formate-bridged action strengthened AgNPs-based surface enhanced fluorescence of the Tb(3+)-DA complex and improved the selectivity towards DA...
August 17, 2017: Analyst
Aisling Byrne, Jaco Jacobs, Christopher S Burke, Aaron Martin, Andreas Heise, Tia E Keyes
A new approach for the fabrication of luminescent ratiometric sensing nanosensors is described using core-shell nanoparticles in which the probe and reference are spatially separated into the shell and core of the nanostructure respectively. The isolation of the reference in the core of the particle ensures a stable emission reference signal unaffected by the external environment. The core shell structure was prepared by engineering structurally well-defined Ru-conjugated block copolymers which acted as emulsifiers in the miniemulsion polymerisation of BODIPY loaded styrene nanoparticles...
August 16, 2017: Analyst
Dongmei Wang, Xiaoqing Xiao, Shen Xu, Yong Liu, Yongxin Li
In this work, single Au nanowire electrodes (AuNWEs) were fabricated by laser-assisted pulling/hydrofluoric acid (HF) etching process, which then were characterized by transmission electron microscopy (TEM), electrochemical method and finite-element simulation. The as-prepared single AuNWEs were used to construct electrochemical aptamer-based nanosensors (E-AB nanosensors) based on the formation of Au-S bond that duplex DNA tagged with methylene blue (MB) was modified on the surface of electrode. In the presence of adenosine triphosphate (ATP), the MB-labeled aptamer dissociated from the duplex DNA due to the strong specific affinity between aptamer and target, which lead to the reduction of MB electrochemical signals...
August 9, 2017: Biosensors & Bioelectronics
Lijun He, Heng Zhang, Huanhuan Fan, Xiuming Jiang, Wenjie Zhao, Guo Qiang Xiang
Herein, we propose a simple and effective strategy for designing a ratiometric fluorescent nanosensor. We designed and developed a carbon dots (CDs) based dual-emission nanosensor for vanadium(V) by coating the surface of dye-doped silica nanoparticles with CDs. The fluorescence of dual-emission silica nanoparticles was quenched in acetic acid through potassium bromate (KBrO3) oxidation. V(V) could catalyze KBrO3 oxidation reaction process, resulting in the ratiometric fluorescence quenching of dual-emission silica nanoparticles...
August 4, 2017: Spectrochimica Acta. Part A, Molecular and Biomolecular Spectroscopy
Wenjing Zhao, Rong-Yao Wang, Hong Wei, Jingliang Li, Yinglu Ji, Xinxin Jiang, Xiaochun Wu, Xiangdong Zhang
The ability to detect chiral molecules renders plasmonic nanosensors as promising tools for the study of chirality phenomena in living systems. Using gold nanorod based plasmonic nanosensors, we investigated here typically chiral zwitterionic electrostatic (Zw-Es) and hydrogen-bonding (Hb) interactions occurring via amine and carboxylic groups at nanoscale interfaces in aqueous solutions. Our results reveal that the plasmonic circular dichroism responses of the nanosensors can have both conformational sensitivity and chiral selectivity to the interfacial molecular interactions...
August 16, 2017: Physical Chemistry Chemical Physics: PCCP
Tatyana O Pleshakova, Kristina A Malsagova, Anna L Kaysheva, Arthur T Kopylov, Vadim Yu Tatur, Vadim S Ziborov, Sergey L Kanashenko, Rafael A Galiullin, Yuri D Ivanov
We report here the highly sensitive detection of protein in solution at concentrations from 10(-15) to 10(-18) m using the combination of atomic force microscopy (AFM) and mass spectrometry. Biospecific detection of biotinylated bovine serum albumin was carried out by fishing out the protein onto the surface of AFM chips with immobilized avidin, which determined the specificity of the analysis. Electrical stimulation was applied to enhance the fishing efficiency. A high sensitivity of detection was achieved by application of nanosecond electric pulses to highly oriented pyrolytic graphite placed under the AFM chip...
August 2017: FEBS Open Bio
Sevinc Kurbanoglu, Sibel A Ozkan
Nanotechnology has become very popular in the sensor fields in recent times. It is thought that the utilization of such technologies, as well as the use of nanosized materials, could well have beneficial effects for the performance of sensors. Nano-sized materials have been shown to have a number of novel and interesting physical and chemical properties. Low-dimensional nanometer-sized materials and systems have defined a new research area in condensed-matter physics within past decades. Apart from the aforesaid categories of materials, there exist various materials of different types for fabricating nanosensors...
June 28, 2017: Journal of Pharmaceutical and Biomedical Analysis
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