- 标题
- 摘要
- 关键词
- 实验方案
- 产品
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Dual-Signal Amplification Strategy for miRNA Sensing with High Sensitivity and Selectivity by Use of Single Au Nanowire Electrodes
摘要： MicroRNAs (miRNAs) have been applied as biomarkers and better detection of their expression profiles plays important roles in early diagnosis of cancers. In this work, a simple dual-signal amplification strategy has been used to construct a novel nanosensor on single Au nanowire electrodes (SAuNWEs) for miRNA-16 detection based on the “signal-on” and “signal-off” features during hybridization/de-hybridization process. The ferrocene-labeled aptamer capture probe (Fc-CP-16) is designed to hybridize with thiolated methylene blue-labeled DNA probe (MB-CP) on SAuNWE to form duplex DNA, and the addition of miRNA-16 can lead to the dissociation of duplex structure due to the highly matched sequences between miRNA-16 and Fc-CP-16. The remaining MB-CP can thus tend to recover its hairpin structure at the presence of Mg2+ through the hybridization of its complementary sequences. During this hybridization/de-hybridization process, the changes of Fc and MB oxidation peaks can be recorded, and there has a linear relationship between the sum of dual-signal changes (ΔI = ΔIMB + |ΔIFc|) and the logarithm of miRNA-16 concentrations, which can be used to detect miRNA-16. Including miRNA extraction, the dual-signal amplification strategy for miRNA sensing assay was carried out about 2 hours for the detection in real samples. This novel nanosensor has small dimension, good selectivity, rapid response and regeneration ability, which can satisfy the need for early cancer marker detection in cells/organelles.
关键词： nanosensors,single Au nanowire electrodes,dual-Signal Amplification Strategy,micro RNA
更新于2025-11-14 17:03:37
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Photoluminescent Ag nanoclusters for reversible temperature and pH nanosenors in aqueous solution
摘要： A facile, straightforward, and green method was reported for the preparation of water-soluble and highly luminescent silver nanoclusters (AgNCs) using captopril (Capt) as a stabilizing agent. The as-prepared Capt@AgNCs exhibited bright red emission with a strong peak centered at 637 nm and showed low toxicity and good stability. Interestingly, the AgNCs displayed temperature sensitivity based on obvious temperature dependence of the fluorescence emission intensity. Furthermore, the AgNCs showed a good reversible and linear response to the environment temperature over the range from 10 °C to 45 °C with a high resolution and activation energy, which allowed its potential application as a fluorescent nanothermometer. In addition, the AgNCs were prepared to monitor pH via the fluorescence intensity of AgNCs responding sensitively to pH fluctuating within a wide range from 2.08 to 6.06. The study provides promising applications as a convenient and eco-friendly fluorescent temperature and pH nanosenser in environmental and biological fields.
关键词： pH nanosensors,Temperature nanosensors,Fluorescence,Silver nanoclusters
更新于2025-09-23 15:22:29
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Luminescent TOP Nanosensors for Simultaneously Measuring Temperature, Oxygen, and pH at a Single Excitation Wavelength
摘要： Two nanosensors for simultaneous optical measurements of the bioanalytically and biologically relevant analytes temperature (“T”), oxygen (“O”), and pH (“P”) have been designed. These “TOP” nanosensors are based on 100 nm-sized silica-coated polystyrene nanoparticles (PS-NPs) doped with a near infrared emissive oxygen- and temperature-sensitive chromium(III) complex ([Cr(ddpd)2][BPh4]3, CrBPh4) and an inert reference dye (Nile Red, NR or 5,10,15,20-tetrakis-(pentafluorophenyl) porphyrin, TFPP) and are covalently labeled with pH-sensitive fluorescein isothiocyanate (FITC). These emitters can be excited at the same wavelength and reveal spectrally distinguishable emission bands allowing for ratiometric intensity-based and time-resolved studies in the visible and near infrared wavelength region. Studies in PBS buffer solutions and in a model body liquid demonstrate the applicability of these nanosensors for the sensitive fluorescence readout of TOP simultaneously at the same position.
关键词： lifetime,fluorescence,chromium(III) complex,oxygen/pH/temperature biosensor,optical multianalyte nanosensors,phosphorescence
更新于2025-09-23 15:22:29
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[Environmental Chemistry for a Sustainable World] Nanosensors for Environmental Applications Volume 43 || Development of Optical Sensor Strips for Point-of-Care Testing for Pesticide
摘要： Disposable or point-of-care sensors are a promising tool for low-cost and rapid sensing of analytes including pesticides. They find important applications in pesticide-contaminated food, agro-products, and water quality monitoring. This chapter highlights the implication and significance of pesticide residue identification in foodstuffs and overviews the most frequently engaged analytical techniques, and finally their benefits and limitations are discussed. Disposable strip-based biosensors have their intrinsic advantages and some disadvantages, but their cost-effectiveness and portability have turned them as a potential possibility for point-of-care (POC) testing of various pesticides. The fabrication of robust, low-cost, reliable, and sensitive sensors with the aid of both simple naked eye-based and portable readout-based detectors is the driving factor in this sensor’s technology area. The pending limitations can be overcome by adapting new specific recognition elements and better signal generative particles or systems. The integration of these devices with card readers or smartphones can make them more user-friendly and will provide more accurate quantitative information.
关键词： Organophosphates,Pesticide,Immunoassay,Aptamer,Biosensors,Immunochromatographic assay,Point-of-care,Antibody,Rapid detection,Nanosensors,Gas chromatography
更新于2025-09-23 15:21:01
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[IEEE SoutheastCon 2018 - St. Petersburg, FL (2018.4.19-2018.4.22)] SoutheastCon 2018 - Advanced Nanomaterials for Bio-Monitoring
摘要： Biomedical and diagnostic detection/monitoring are of great importance to society, as these areas directly impact our daily lives. This need is prevalent in the workings of wearable biosensors, as the biosensor market is projected to be a $US 22.5 billion dollar industry by 2020. Hence, the development of sensors utilizing the often enhanced properties of nanoscale materials is at the forefront of wearable analytical chemistry. Nanoscience presents an almost endless amount of novel materials, as their properties differ from their bulk counterparts. Many of the interactions with these nanomaterials remain unexplored, leaving a need for investigation. Both the structure and the materials should be soft and mechanically robust enough to bend, stretch, fold, and twist in response to the motion of the wearer. Here, electrospun polymer fibers have been used as wearable sensors, and further functionalized with a wide loading range of carbon nanomaterials via layer-by-layer and vacuum techniques to accommodate multiple analyte detection schemes in sweat. The data demonstrates the success of a nanocomposite sensor at monitoring in an accurate, selective, and reproducible manner. It is capable of outputting currents, at low voltages (< 1 V), that can easily be read via a portable/wearable device, enhancing the sensor’s attractiveness for wearable/flexible devices.
关键词： nanomaterials,advanced materials,wearable,nanosensors,biosensors
更新于2025-09-23 15:21:01
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Self-Organized Nanorod Arrays for Large-Area Surface Enhanced Infrared Absorption
摘要： Highly sensitive Surface Enhanced Infrared Absorption (SEIRA) spectroscopy capabilities are demonstrated by exploiting large-area templates (cm2) based on self-organized (SO) nanorod antennas. We engineered highly dense arrays of gold nanorod antennas featuring polarization-sensitive localized plasmon resonances, tunable over a broadband near- and mid-infrared (IR) spectrum, in overlap with the so called ‘functional group’ window. We demonstrate polarization-sensitive SEIRA activity, homogenous over macroscopic areas and stable in time, by exploiting prototype self-assembled monolayers of IR-active octadecanthiol (ODT) molecules. The strong coupling between the plasmonic excitation and the molecular stretching modes give rise to characteristic Fano resonances in SEIRA. The SO engineering of the active hot-spots in the arrays allows to achieve signal amplitude improved up to the 5.7 %. This figure is competitive to the response of lithographic nanoantennas and is stable when the optical excitation spot varies from the micro- to the macroscale, thus enabling highly sensitive SEIRA spectroscopy on cost-effective nanosensor devices.
关键词： IR spectroscopy,large area nanosensors,Surface Enhanced Infra-Red Absorption (SEIRA),self-organized arrays,Fano resonances,Plasmonic nanoantennas
更新于2025-09-23 15:19:57
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Nanomaterials for luminescent detection of water and humidity
摘要： The rapid and sensitive detection of water or humidity has attracted wide interest because of their considerable significance in the chemical industry and other fields. Nanotechnology offers potential tools in the construction of various luminescent nanosensors for sensing water or relative humidity (RH). In this review, we present the recent advances in different luminescent nanomaterials, namely, luminescent copper nanoclusters, carbon quantum dots, metal–organic frameworks, covalent organic frameworks and other nanomaterials, in the detection of water and RH. Also, the challenges and opportunities are discussed.
关键词： luminescent detection,nanomaterials,humidity,nanosensors,water
更新于2025-09-19 17:15:36
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Octupolar Plasmonic Nanosensor Based on Ordered Arrays of Triangular Au Nanopillars for Selective Rotavirus Detection
摘要： Technologies based on plasmonic nanostructures are a rapidly growing field that aims to be a valid alternative to conventional diagnostic tools. One of the main goals in their technological development, consists in the design of systems for a sensitive and specific detection of pathogens in water. Among these, Rotavirus represent the main cause of childhood viral gastroenteritis in humans. In this work, we design functionalized plasmonic label-free nanosensors based on Localized Surface Plasmon Resonance (LSPR) sensing to detect ultralow concentration of Rotavirus. We demonstrate the possibility to detect in a specific way amounts lower than 103 plaque forming unit (PFU)/mL of the Rotavirus in water using a very low sample volume (2 μl). These results together with those obtained in our specificity tests performed with two different viruses (Bovine Herpesvirus -BHV1 and Equine viral arteritis -EVA) confirm that our device is very promising to develop a rapid, simple, very sensitive and specific immunoassay for detection of Rotavirus. To the best of our knowledge, this is the first time that LSPR nanobiosensing has been used for the sensitive and specific detection of Rotavirus.
关键词： Functionalization,LSPR,Rotavirus,Nanosensors,Plasmonic
更新于2025-09-19 17:13:59
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On-demand Milifluidic Synthesis of Quantum Dots in Digital Droplet Reactors
摘要： Colloidal quantum dots (QDs) offer dramatic potential due to their size-dependent optical properties. Lack of facile synthesis methods for precise and reproducible size and composition, however, present an extant barrier to their widespread use. Here we report the use of droplet microfluidics for the simple and highly reproducible synthesis of cadmium sulfide (CdS) and cadmium selenide (CdSe) QDs without the use of harsh solvents and in ambient conditions. Our approach uses a liquid-liquid barrier between two immiscible liquids to generate a digital droplet reactor. This reaction droplet is easily controlled and manipulated and offers enhanced mixing when coupled to a helical mixer, resulting in a significant reduction in size distribution compared to benchtop procedures. Furthermore, QD characteristics have modeled and predicted based on the parameters of the microfluidic device. We believe this method overcomes the current manufacturing challenges with synthesizing nanostructures, which is required for the next generation of nanosensors.
关键词： CdS,CdSe,quantum dots,microfluidics,nanosensors
更新于2025-09-12 10:27:22
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Genetically encoded FRET-based optical sensor for Hg2+ detection and intracellular imaging in living cells
摘要： Due to the potential toxicity of mercury, there is an immediate need to understand its uptake, transport and flux within living cells. Conventional techniques used to analyze Hg2+ are invasive, involve high cost and are less sensitive. In the present study, a highly efficient genetically encoded mercury FRET sensor (MerFS) was developed to measure the cellular dynamics of Hg2+ at trace level in real time. To construct MerFS, the periplasmic mercury-binding protein MerP was sandwiched between enhanced cyan fluorescent protein (ECFP) and venus. MerFS is pH stable, offers a measurable fluorescent signal and binds to Hg2+ with high sensitivity and selectivity. Mutant MerFS-51 binds with an apparent affinity (Kd) of 5.09 × 10?7 M, thus providing a detection range for Hg2+ quantification between 0.210?μM and 1.196?μM. Furthermore, MerFS-51 was targeted to Escherichia coli (E. coli), yeast and human embryonic kidney (HEK)-293T cells that allowed dynamic measurement of intra- cellular Hg2+ concentration with a highly responsive saturation curve, proving its potential application in cellular systems.
关键词： Genetically encoded,FRET,Fluorescent proteins,Mercury,Nanosensors
更新于2025-09-11 14:15:04