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Yinghua Liu, Wenxiu Duan, Wei Song, Juanjuan Liu, Cuiling Ren, Jiang Wu, Dan Liu, Hongli Chen
Colorimetric and fluorescent dual mode detection methods have gained much attention in recent years, however, it is still desirable to develop new colorimetric and fluorescent dual mode nanosensors with more simple preparation procedure, low cost and excellent biocompatibility. Herein, a colorimetric and fluorescent nanosensor based on B, N, S-co-doped carbon dots (BNS-CDs) were synthesized by one-step hydrothermal treatment of 2, 5-diaminobenzenesulfonic acid and 4-aminophenylboronic acid hydrochloride. Using this nanosensor, a highly sensitive assay of Fe3+ in the range of 0...
March 24, 2017: ACS Applied Materials & Interfaces
Yang Liu, Yanan Liu, Jinpyo Lee, Joong Hee Lee, Mira Park, Hak Yong Kim
As one of the most promising fluorometric nanosensors for metal ion sensing, carbon nanodots (C-dots) have developed rapidly in recent years. However, it is still a thorny problem to shield the mutual interference of two metal ions towards C-dots, e.g., Hg(2+) and Fe(3+) ions. In the present work, we propose rational routes for the unique interaction between C-dots and Hg(2+) or Fe(3+). The selectivity of the as-obtained label-free C-dots can be effectively switched by P3O10(5-) and SCN(-). The resultant C-dots possess superior photoluminescence intensity stability in a wide pH range or in certain redox circumstances, which are highly preferred in terms of practical metal-ion detection...
March 20, 2017: Analyst
Torsten Rendler, Jitka Neburkova, Ondrej Zemek, Jan Kotek, Andrea Zappe, Zhiqin Chu, Petr Cigler, Jörg Wrachtrup
Development of multifunctional nanoscale sensors working under physiological conditions enables monitoring of intracellular processes that are important for various biological and medical applications. By attaching paramagnetic gadolinium complexes to nanodiamonds (NDs) with nitrogen-vacancy (NV) centres through surface engineering, we developed a hybrid nanoscale sensor that can be adjusted to directly monitor physiological species through a proposed sensing scheme based on NV spin relaxometry. We adopt a single-step method to measure spin relaxation rates enabling time-dependent measurements on changes in pH or redox potential at a submicrometre-length scale in a microfluidic channel that mimics cellular environments...
March 20, 2017: Nature Communications
Ulhas S Kadam, Burkhard Schulz, Joseph M K Irudayaraj
Here we demonstrate multiplex and simultaneous detection of four different rare RNA species from plant, Arabidopsis thaliana, using surface enhanced Raman spectroscopy and gold nanoprobes at single cell resolution. We show the applicability of nanoparticle-based Raman spectroscopic sensor to study intracellular RNA copies. First, we demonstrate that gold-nanoparticles decorate with Raman probes and carrying specific nucleic acid probe sequences can be uptaken by the protoplasts. We confirm the internalization of gold nanoprobes by TEM, ICP-MS, and fluorescence imaging...
March 16, 2017: Plant Journal: for Cell and Molecular Biology
Florent Seichepine, Jörg Rothe, Alexandra Dudina, Andreas Hierlemann, Urs Frey
Carbon-nanotube (CNT)-based sensors offer the potential to detect single-molecule events and picomolar analyte concentrations. An important step toward applications of such nanosensors is their integration in large arrays. The availability of large arrays would enable multiplexed and parallel sensing, and the simultaneously obtained sensor signals would facilitate statistical analysis. A reliable method to fabricate an array of 1024 CNT-based sensors on a fully processed complementary-metal-oxide-semiconductor microsystem is presented...
March 15, 2017: Advanced Materials
Lijia Liang, Huixin Qu, Biying Zhang, Jing Zhang, Rong Deng, Yanting Shen, Shuping Xu, Chongyang Liang, Weiqing Xu
Sialoglycan expression is critical for assessing various diseases progression. Especially, its abnormal levels are commonly believed to be associated with tumor and metastatic cancer types. While, complicated structures, multiple types and dynamic distributions make it challenging for in situ investigating sialoglycans at the physiological status. Herein, we developed a 4-mercaptophenylboronic acid (MPBA)-based surface-enhanced Raman scattering (SERS) nanosensor to in situ study sialoglycan levels and dynamic expression processes of different cell types based on molecular recognition between phenylboronic acid and sialoglycans at physiological condition...
February 27, 2017: Biosensors & Bioelectronics
Zhong Mei, Yanyan Wang, Liang Tang
Gold nanorod (GNR) based label-free sensing has been attractive due to its unique property of localized surface plasmon resonance (LSPR). Compared to bulk gold, the SPR of GNRs is more sensitive to the refractive index change caused by biological binding in the close proximity. Numerous studies have reported biological detection in solution based GNR probes. However, the biosensing has the intrinsic problems of fluctuating readings and short storage time due to nanoparticle aggregation. In contrast, a chip-based nanorod biosensor is a more robust and reliable platform...
2017: Methods in Molecular Biology
E Goux, E Dausse, V Guieu, L Azéma, G Durand, M Henry, L Choisnard, J-J Toulmé, C Ravelet, E Peyrin
Herein, we report a novel approach for the design of a colorimetric aptasensor based on functionalized gold nanoparticle probes. This approach relies on the conjugation of nanoparticles by two functional DNA and RNA hairpins that engage specific kissing (loop-loop) interactions in response to the addition of a small analyte ligand, leading to particle aggregation and then red-to-purple colour change of the colloidal solution.
March 9, 2017: Nanoscale
Hongyan Zhang, Zhenhong Jia
A new type of fluorescence "off-on" probe was designed for L-Cysteine (L-Cys) based on the fluorescence resonance energy transfer (FRET) between negatively charged amino-capped porous silicon nanoparticles (SiNPs) and positively charged citrate-stabilized Au nanoparticles (AuNPs). In this proposed FRET immunosensor, novel water-soluble amino-conjugated porous SiNPs in ethanol with excellent photoluminescence properties act as the energy donor. Excellent quenching efficiency between SiNPs-ethanol and citrate-stabilized AuNPs by electrostatic interaction via FRET provides an ideal "off-state" (turn-off)...
March 5, 2017: Sensors
X J Zhao, Wen-Wen Shan, Hao He, Xinlian Xue, Z X Guo, S F Li
Transition metal (TM) nanostructures, such as one dimensional (1D) nanowires with/without substrates, usually possess drastically different properties from their bulk counterparts, due to their distinct stacking and electronic confinement. Correspondingly, it is of great importance to establish the dominant driving force in forming 1D single-metal-atom-wires (SMAWs). Here, with first-principles calculations, taking the black phosphorene (BP) monolayer as a prototype 2D substrate, we investigate the energetic and kinetic properties of all the 5d-TM atoms on the 2D substrate to reveal the mechanism of formation of SMAWs...
March 6, 2017: Physical Chemistry Chemical Physics: PCCP
Si Chen, Jared Weddell, Pavan Gupta, Grace Conard, James Parkin, Princess I Imoukhuede
Nanosensor-based detection of biomarkers can improve medical diagnosis; however, a critical factor in nanosensor development is deciding which biomarker to target, as most diseases present several biomarkers. Biomarker-targeting decisions can be informed via an understanding of biomarker expression. Currently, immunohistochemistry (IHC) is the accepted standard for profiling biomarker expression. While IHC provides a relative mapping of biomarker expression, it does not provide cell-by-cell readouts of biomarker expression or absolute biomarker quantification...
2017: Methods in Molecular Biology
Joel Wellbourne-Wood, Theresa S Rimmele, Jean-Yves Chatton
Neuronal activity results in the release of [Formula: see text] into the extracellular space (ECS). Classically, measurements of extracellular [Formula: see text] ([Formula: see text]) are carried out using [Formula: see text]-sensitive microelectrodes, which provide a single point measurement with undefined spatial resolution. An imaging approach would enable the spatiotemporal mapping of [Formula: see text]. Here, we report on the design and characterization of a fluorescence imaging-based [Formula: see text]-sensitive nanosensor for the ECS based on dendrimer nanotechnology...
January 2017: Neurophotonics
Yang Zhang, Hong Yang, Zhiguo Zhou, Kai Huang, Shiping Yang, Gang Han
Magnetic relaxation switching assay (MRSw)-based nanosensors respond to the changes of transverse relaxation time (T2) of water molecules resulted from the analyte-induced aggregation and disaggregation of magnetic nanoparticles (MNPs). This strategy has been widely applied to the detections of various substrates from heavy metal ions to organic pollutants, proteins, nucleic acids, bacteria and viruses, and specific cells. Compared with other nanosensors, MRSw-based nanosensors not only are free from the background interferences, signal bleaching, and quenching but also overcome light scattering from samples without pretreatments...
February 28, 2017: Bioconjugate Chemistry
Jing-Ru Wei, Yan-Li Ni, Wei Zhang, Zhi-Qi Zhang, Jing Zhang
A novel strategy based on the fluorescent molecularly imprinted polymers (FMIP) for specific recognition and sensitive sensing glycoprotein from biological samples was developed. The FMIP prepared by introducing a fluorescent boronic acid quinoline-based on the PGMA/EDMA bead surface and assembled a glycoprotein molecularly imprinted polymer using surface imprinting technology. The resultant material showed specific recognition to model glycoprotein. At the same time, the change of fluorescence caused by the amount of model glycoprotein could achieve quantitative determination...
April 1, 2017: Analytica Chimica Acta
Yangyang Zhang, Shilei Li, Zhenwen Zhao
Nanoliposomes were first used to encapsulate two fluorophores, fluorescein and cresyl violet, to construct a FRET-based ratiometric fluorescent probe, for sensing intracellular pH values. The morphology, stability, interference factors, biocompatibility, and performance were investigated in detail. The fluorophores-encapsulated nanoliposomes (FEN) probe can be uptaken by cells within 30 min, which is faster than any other nanosensor, and cell viability was not significantly changed upon treatment with the FEN probe for 24 h, showing the low cytotoxicity and good biocompatibility of the probe...
December 20, 2016: Analytical Chemistry
Hong Huang, Fangyuan Dong, Yang Tian
Intracellular pH undertakes critical functions in the formation of a proton gradient and electrochemical potential that drives the adenosine triphosphate synthesis. It is also involved in various metabolic processes occurring in mitochondria, such as the generation of reactive oxygen species, calcium regulation, as well as the triggering of cell proliferation and apoptosis. Meanwhile, the aberrant accumulation of O2(•-) within mitochondria is frequently intertwined with mitochondrial dysfunction and disease development...
December 20, 2016: Analytical Chemistry
Kaixuan Nie, Bo Dong, Huanhuan Shi, Zhengchun Liu, Bo Liang
A technique for encapsulating fluorescent organic probes in a micelle system offers an important alternative method to manufacture water-soluble organic nanoparticles (ONPs) for use in sensing Hg(2+). This article reports on a study of a surfactant-free micelle-like ONPs based on a 3,6-di(2-thienyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (TDPP) amphiphile, (2-(2-(2-methoxyethoxy)ethyl)-3,6-di(2-thiophyl)-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione (NDPP) fabricated to monitor Hg(2+) in water. NDPP was synthesized through a simple one-step modification of a commercially available dye TDPP with a flexible and hydrophilic alkoxy...
February 15, 2017: Analytical Chemistry
Li Yang, Danni Liu, Shuai Hao, Fengli Qu, Ruixiang Ge, Yongjun Ma, Gu Du, Abdullah M Asiri, Liang Chen, Xuping Sun
Nanostructures possess distinct quenching ability toward fluorophores with different emission frequencies and have been intensively used as nanoquenchers for homogeneous nucleic acid detection. Complete understanding of such a sensing system will provide significant guidance for the design of superior sensing materials, which is still lacking. In this Letter, we demonstrate the development of FeP nanowires as a nanoquencher for high-performance fluorescent nucleic acid detection with much superior performance to α-Fe2O3 counterparts...
February 1, 2017: Analytical Chemistry
Antonio Tirado-Guizar, Francisco Paraguay-Delgado, Georgina E Pina-Luis
A new 'turn-on' Förster resonance energy transfer (FRET) nanosensor for l-tryptophan based on molecularly imprinted quantum dots (QDs) is proposed. The approach combines the advantages of the molecular imprinting technique, the fluorescent characteristics of the QDs and the energy transfer process. Silica-coated CdTe QDs were first synthesized and then molecularly imprinted using a sol-gel process without surfactants. The final composite presents stable fluorescence which increases with the addition of l-tryptophan...
November 17, 2016: Methods and Applications in Fluorescence
O Lupan, V Postica, N Wolff, O Polonskyi, V Duppel, V Kaidas, E Lazari, N Ababii, F Faupel, L Kienle, R Adelung
A composed morphology of iron oxide microstructures covered with very thin nanowires (NWs) with diameter of 15-50 nm has been presented. By oxidizing metallic Fe microparticles at 255 °C for 12 and 24 h, dense iron oxide NW networks bridging prepatterned Au/Cr pads are obtained. X-ray photoelectron spectroscopy studies reveal formation of α-Fe2 O3 and Fe3 O4 on the surface and it is confirmed by detailed high-resolution transmission electron microscopy and selected area electron diffraction (SAED) investigations that NWs are single phase α-Fe2 O3 and some domains of single phase Fe3 O4 ...
February 10, 2017: Small
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