- 标题
- 摘要
- 关键词
- 实验方案
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Plasmonic Colorimetric Biosensor for Visual Detection of Telomerase Activity Based on Horseradish Peroxidase-Encapsulated Liposomes and Etching of Au Nanobipyramids
摘要： Telomerase aberrant activation is a critical feature in the vast majority of cancers. To visualize telomerase expression level in tumor cells, we developed a plasmonic colorimetric sensor for highly sensitive detection of telomerase activity by integrating an excellent etching substrate Au nanobipyramids (Au NBPs) with a liposome-based signal amplification strategy. Upon telomerase-triggered extension, the telomerase activity was converted into the amount of the attached horseradish peroxidase-encapsulated liposomes (HRP-Ls) on the surfaces of magnetic beads. Afterwards, HRP was liberated from the liposomes following the addition of H2O2-3,3′,5,5′-tetramethylbenzidine sulfate (TMB) substrate, and then the oxidation reaction between H2O2 and TMB was initiated to form TMB2+. The morphological evolution of Au NBPs relied on the TMB2+-mediated etching reaction, which gave rise to tremendous localized surface plasmon resonance (LSPR) responses and concomitant tonality transitions. Benefiting from cascaded signal amplification capacity of HRP-Ls and the intriguing optical properties of Au NBPs, an impressive sensitivity toward telomerase was obtained with detection limits equivalent to 1 HeLa cell for LSPR peak measurement and a visual detection limit of 20 HeLa cells. Furthermore, a facile and portable kit was fabricated for visual evaluation of telomerase activity in different cell lines.
关键词： Plasmonic colorimetry,Au nanobipyramids,Telomerase,Liposome-based amplification,Multicolor visual detection
更新于2025-11-14 17:04:02
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Dual-emission color-controllable nanoparticle based molecular imprinting ratiometric fluorescence sensor for the visual detection of Brilliant Blue
摘要： Single-component dual-emission nanoparticles were synthesized by chelating the organic ligand 8-hydroxyquinoline (HQ) to the surface of CdTe/ZnS quantum dots, namely CdTe/ZnQ2, and were used to construct a novel mesoporous structured molecular imprinting ratiometric fluorescence sensor by facile one-pot sol-gel polymerization for the visual detection of Brilliant Blue. The CdTe/ZnQ2 had bimodal fluorescence belonging to CdTe and ZnQ2 segments, respectively; significantly, the emission wavelength of CdTe was optimized to be 630 nm for the largest overlap with the absorption spectrum of Brilliant Blue. Consequently, fluorescence resonance energy transfer (FRET) efficiency was greatly enhanced, resulting in ideal determination. A favorable linearity toward Brilliant Blue was obtained within 0–1.0 μmol?L-1 along with profuse color evolution from orange to yellowish orange to yellowish green to green, and a high detectability of 8.8 nmol?L-1 was offered. Excellent recognition selectivity for Brilliant Blue over possibly coexistent food colorants was demonstrated, with a high imprinting factor of 7.1. Furthermore, endogenous Brilliant Blue was detected ranging from 0.21–41.03 mg/kg in six typical food samples with relative standard deviations lower than 3.5%, and the results agreed well with that afforded by conventional methods. Using Brilliant Blue as a model, this dual-emission color-controllable nanoparticle based imprinting ratiometric fluorescence sensor provided promising perspectives for the highly selective and sensitive, rapid, visual detection of colored substances in complicated matrices.
关键词： Molecular imprinting,Brilliant Blue,Dual-emission nanoparticles,Ratiometric fluorescence,Visual detection
更新于2025-09-23 15:23:52
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Dual-Emitting Quantum Dot Complex Nanoprobe for Ratiometric and Visual Detection of Hg2+ and Cu2+ ions
摘要： Herein we report the use of a dual emitting quantum dot complex (QDC; composed of blue emitting metal-methylsalicylaldimine complex being on the surface of orange emitting Mn2+-doped ZnS quantum dot) for ratiometric and visual detection of Hg2+ and Cu2+ ions - following the alterations in luminescence color, intensity ratio, chromaticity and hue of the QDC.
关键词： Hg2+ ions,Cu2+ ions,ratiometric detection,quantum dot complex,visual detection
更新于2025-09-23 15:21:01
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Highly sensitive and ultrafast film sensor based on polyethyleneimine-capped quantum dots for trinitrophenol visual detection
摘要： Real-time detection of nitroaromatic explosives is a pressing problem for public security and environmental monitoring. Although many efforts have been devoted, sensing of explosives still suffers limitations of complicated and time-consuming sensing procedure. In this work, we develop a fluorescent film for 2,4,6-trinitrophenol (TNP) detection of rapid and visual by using polyethyleneimine-capped quantum dots(QDs-PEI) as fluorescent sensing probe and electrospun membrane as matrix. Fluorescent sensing is mainly based on effective reaction between amino groups of PEI and nitro groups, phenol hydroxyl groups of TNP. It also benefits from the rapid absorption of TNP in aqueous solution by PA6 nanofiber membranes with high hydrophilicity and porosity. As a result, visual sensing could be realized when TNP is more than 100 ng.mL-1 by obvious fluorescent change with a thirty-second response time. We believe this fluorescent membrane sensor holds a promising prospect for real time and visual detection of TNP in environmental science and analytical fields.
关键词： Visual Detection,Quantum dots,Fluorescent sensor,2,4,6-trinitrophenol
更新于2025-09-23 15:19:57
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Recent advances in dual-emission ratiometric fluorescence probes for chemo/biosensing and bioimaging of biomarkers
摘要： A biomarker-based detection improves early diagnosis and subsequent treatment of diseases. Chemo/biosensing and bioimaging play a crucial role in biomarker detection. Ratiometric fluorescence (FL) probes provide built-in self-calibration for the correction of various target-independent factors and attract particular attention for analytical sensing and optical imaging. Based on the potential to provide a precise, quantitative, visual and real-time analysis, ratiometric FL probes are widely employed for chemo/biosensing and bioimaging detection of biomarkers. In this review, we systematically summarize the recent progress on dual-emission ratiometric FL probes. First, two general categories of ratiometric FL probes are introduced, involving ratiometric FL with one reference signal and two reversible signal changes. Then, fabrication methods of ratiometric FL probes are summarized in detail, including nanoparticle- or organic dye-embedded probes with dual-emission FL, fluorescent nanoparticles and organic dyes dual-embedded probes. Analytical applications of ratiometric FL probes are described overall, referring to different biomarker types and detection mechanisms, ratiometric FL chemo/biosensing in external samples and FL visual detection, ratiometric FL bioimaging in cells and tissues of small animals. Current states, probable challenges and future perspectives of ratiometric FL probes for biomarker detection are discussed rationally. This comprehensive review is attractive for numerous scientists from different areas, such as material science, chemistry, biomedicine, engineering, physics, etc. This review covers a wide range of scientific disciplines and benefits further development of functionalized optical materials, luminescent devices and bioimaging technique.
关键词： Biomarkers,Biosensors,Visual detection,Bioimaging,Ratiometric fluorescence
更新于2025-09-19 17:15:36
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Ultrafast, sensitive and visual sensing of copper ions by a dual-fluorescent film based on quantum dots
摘要： The use of fluorescent sensors is one of the most promising approaches for meeting the growing demand for a sensitive, convenient and cost-effective detection method of metal ions. However, visual sensing based on fluorescent materials remains a challenge due to the hard-to-see changes in fluorescence intensity, long response time and poor stability. Here, a simple and effective film sensor was developed for the visual detection of Cu2+ using quantum dots (QDs) modified by polyethylenimine (PEI) and poly(vinylidene fluoride) (PVDF) by electrospinning and dip-coating methods. QDsr-PEI on the surface of nanofibers could be used as a responsive red fluorescence signal, while the QDsg dispersed in the nanofibers were used as a green background signal. Due to the high Cu2+ binding capacity of PEI and the contrast-color sensitivity of the two kinds of QDs, it realized an obvious fluorescence change from red to green toward Cu2+ in the liquid phase with a short response time of 30 s and a low detection limit of 2 mM by observation. Furthermore, the film exhibited excellent fluorescence stability to a high temperature and UV light, which is beneficial for satisfying much more possible applications. These results demonstrate that the dual fluorescent film sensor has a great potential for the real-time and visual detection of Cu2+.
关键词： dip-coating,fluorescent sensors,visual detection,Cu2+,quantum dots,electrospinning
更新于2025-09-16 10:30:52
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Optical Detection of Denatured Ferritin Protein via Plasmonic Gold Nanoparticles Exposure through Aminosilane Solution
摘要： The presence of denatured proteins within a therapeutic drug product can create a series of serious adverse effects, such as mild irritation, immunogenicity, anaphylaxis, or instant death to a patient. The detection of protein degradation is complicated and expensive due to current methods associated with expensive instrumentation, reagents, and processing time. We have demonstrated here a platform for visual biosensing of denatured proteins that is fast, low cost, sensitive, and user friendly by exploiting the plasmonic properties of noble metal nanoparticles. In this study we have exposed artificially heat stressed ferritin and gold nanoparticles to 3-aminopropyl triethoxysilane, which degrades the protein by showing a systematic blue shift in the absorbance spectra of the gold nanoparticle/ferritin and aminosilane solution. This blue shift in absorbance produces a detectable visual color transition from a blue color to a purple hue. By studying the Raman spectroscopy of the gold nanoparticle/ferritin and aminosilane solution, the extent of ferritin degradation was quantified. The degradation of ferritin was again confirmed using dynamic light scattering and was attributed to the aggregation of the ferritin due to accelerated heat stress. We have successfully demonstrated a proof of concept for visually detecting ferritin from horse spleen that has experienced various levels of degradation, including due to heat stress.
关键词： ferritin,gold nanoparticles,biosensor,denatured protein,degraded protein,visual detection
更新于2025-09-16 10:30:52
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A target analyte induced fluorescence band shift of piperazine modified carbon quantum dots: a specific visual detection method for oxytetracycline
摘要： Through the protection/deprotection of one amine group and the amidation reaction, piperazine was used to modify carbon quantum dots (CQDs) and successfully served as a medium to combine oxytetracyclines (OTC) in solution by hydrogen bonding and electrostatic interactions. Fluorescence resonance energy transfer (FRET) probably occurred between piperazine modified CQDs (P-CQDs) and combined OTC, which resulted in the red-shift of the fluorescence band. Besides superior specificity for examining, a good linear relationship between the maximum emission wavelength of P-CQDs and concentrations of OTC (0 to 10 lM) can be obtained, which provides a rapid and convenient visual fluorescence detection method of OTC.
关键词： carbon quantum dots,oxytetracycline,visual detection,fluorescence resonance energy transfer,piperazine
更新于2025-09-12 10:27:22
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Molecularly Imprinted Fluorescent Test Strip for Direct, Rapid, and Visual Dopamine Detection in Tiny Amount of Biofluid
摘要： Paper-based assays for detection of physiologically important species are needed in medical theranostics owning to their superiorities in point of care testing, daily monitoring, and even visual readout by using chromogenic materials. In this work, a facile test strip is developed for visual detection of a neurotransmitter dopamine (DA) based on dual-emission fluorescent molecularly imprinted polymer nanoparticles (DE-MIPs). The DE-MIPs, featured with tailor-made DA affinity and good anti-interference, exhibit DA concentration-dependent fluorescent colors, due to the variable ratios of dual-emission fluorescence caused by DA binding and quenching. By facile coating DE-MIPs on a filter paper, the DA test strips are obtained. The resultant test strip, like the simplicity of a pH test paper, shows the potential for directly visual detection of DA levels just by dripping a tiny amount of biofluid sample on it. The test result of real serum samples demonstrates that the DA strip enables to visually and semiquantitatively detect DA within 3 min by using only 10 μL of serum samples and with a low detection limit ((100–150) × 10?9 m) by naked eye. This work thus offers a facile and efficient strategy for rapid, visual, and on-site detection of biofluids in clinic.
关键词： molecular imprinting,dual-emission fluorescence,visual detection,paper-based assays,dopamine
更新于2025-09-10 09:29:36
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A Vision-Based Approach to UAV Detection and Tracking in Cooperative Applications
摘要： This paper presents a visual-based approach that allows an Unmanned Aerial Vehicle (UAV) to detect and track a cooperative ?ying vehicle autonomously using a monocular camera. The algorithms are based on template matching and morphological ?ltering, thus being able to operate within a wide range of relative distances (i.e., from a few meters up to several tens of meters), while ensuring robustness against variations of illumination conditions, target scale and background. Furthermore, the image processing chain takes full advantage of navigation hints (i.e., relative positioning and own-ship attitude estimates) to improve the computational ef?ciency and optimize the trade-off between correct detections, false alarms and missed detections. Clearly, the required exchange of information is enabled by the cooperative nature of the formation through a reliable inter-vehicle data-link. Performance assessment is carried out by exploiting ?ight data collected during an ad hoc experimental campaign. The proposed approach is a key building block of cooperative architectures designed to improve UAV navigation performance either under nominal GNSS coverage or in GNSS-challenging environments.
关键词： autonomous navigation,morphological ?ltering,visual detection,unmanned aerial vehicles,visual tracking,template matching,cooperative UAV applications
更新于2025-09-09 09:28:46