- 标题
- 摘要
- 关键词
- 实验方案
- 产品
过滤筛选
- 2018
- metal object detection (MOD)
- wireless power transfer (WPT)
- auxiliary detection coil
- Chest X-ray (CXR)
- Computer-aided Diagnosis (CADx)
- Early detection of tuberculosis
- Electrical Engineering and Automation
- Optoelectronic Information Science and Engineering
- Shanghai Jiao Tong University
- Bandung Institute of Technology (ITB)
-
Fluorometric determination of glucose based on a redox reaction between glucose and aminopropyltriethoxysilane and in-situ formation of blue-green emitting silicon nanodots
摘要： A method is described for fluorometric detection of glucose. It is based on the finding that silicon nanodots (SNDs) are formed from glucose and aminopropyltriethoxysilane (APTES) under mild experimental conditions. The SNDs thus formed have an average diameter of ～2 nm, exhibit good water dispersibility, blue fluorescence (with excitation/emission maxima at 410/475 nm), broad pH tolerance, and are photostable. The assay was applied to the quantification of glucose with high sensitivity, good specificity, and over a wide detection range (from 10 μM to 0.9 mM). It was applied to the determination of glucose in spiked serum samples and gave satisfactory results and recoveries.
关键词： Fluorescence detection,Enzyme-free analysis,Diabetes,Silicon nanoparticles
更新于2025-09-23 15:23:52
-
Rapid and sensitive detection of formaldehyde using portable 2-dimensional gas chromatography equipped with photoionization detectors
摘要： We developed an automated and highly portable device for rapid and sensitive formaldehyde detection based on heart-cutting 2-dimensional gas chromatography. In this design, the air sample was first absorbed by a preconcentrator before it is injected into the 1st-dimensional column (Rtx?-VMS). The partial elution from the 1st-dimensional column containing formaldehyde was re-injected into the 2nd-dimensional column (Rt? Q-BOND column) for further separation. The detection of formaldehyde was achieved by using a micro-helium dielectric barrier discharge photoionization detector that is able to ionize formaldehyde (ionization potential = 10.88 eV). Due to the use of many miniaturized components, the entire system has a weight of only 1.3 kg (excluding the helium cartridge) and dimensions of only 27 cm x 24 cm x 12 cm. It is capable of detecting formaldehyde down to 0.5 ppb (V/V) with a signal-to-noise ratio of 6 in only 11 min (including 6 min of sampling). Meanwhile, simultaneous separation and detection of other air pollution related toxic compounds, such as benzene, toluene, ethylbenzene, and xylene, was also demonstrated by the 1-dimensional column and a flow-through micro-photoionization detector. The device developed here should have a broad range of applications in environmental protection, industries, space exploration, and battlefield.
关键词： Gas chromatography,Air quality control,Indoor air analysis,Photoionization detector,2D GC,Formaldehyde detection
更新于2025-09-23 15:23:52
-
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
-
Highly selective and sensitive xylene gas sensor fabricated from NiO/NiCr2O4 p-p nanoparticles
摘要： Xylene is a harmful and hazardous volatile organic compound (VOC) indoors, thus selective and sensitive detection for subppm-level xylene is crucial, however a remained challenge. In this work, p-NiO/p-NiCr2O4 nanocomposites were successfully synthesized through a simple hydrothermal route and used as sensing materials. In the comparative gas sensing test, the sensor fabricated from NiO/NiCr2O4 (Cr/Ni=25 at%) nanocomposite exhibited the highest response (66.2-100 ppm) to xylene, which was 37.2 times higher than that of the pure NiO sensor. Moreover, the NiO/NiCr2O4 nanocomposite gas sensor showed not only superior xylene selectivity with low cross-responses to interfering gases such as ethanol (Sxylene/Sethanol =11.8) and acetone (Sxylene/Sacetone =10.2) but also ppb-level detection limit (1.2-50 ppb xylene) at 225 °C. The synergistic catalytic effect between NiO and NiCr2O4, optimized structural parameters and marked resistive variation due to the formation of nanoscale p-p heterojunctions were regarded as the main reasons for the ultrasensitive and selective xylene detection.
关键词： selectivity,xylene detection,heterojunction,gas sensor,NiO/NiCr2O4
更新于2025-09-23 15:23:52
-
Label-free fluorescent discrimination and detection of epinephrine and dopamine based on bioinspired in situ copolymers and excitation wavelength switch
摘要： A simple and label-free fluorescence turn-on method is proposed for the discrimination and detection of epinephrine (Ep) and dopamine (DA) via polyethyleneimine (PEI)-initiated in situ copolymerization and excitation wavelength switch. The PEI solution in the presence of Ep, DA and the mixture of Ep and DA are denoted as PEp-PEI, PDA-PEI and MEptDA, respectively. In this study, PEI aqueous solution medium initiates the auto-oxidization of Ep and DA and the bioinspired copolymerization. These resultant copolymers emit yellow-green fluorescence color with a fluorescence emission maximum at 515 nm. Interestingly, these fluorescent copolymers exhibit distinct different excitation spectra, although Ep and DA are structurally very similar. PDA-PEI exhibits only one excitation peak at 385 nm, and PEp-PEI shows dual-excitation mode with two significant excitation peaks at 328 nm and 405 nm, respectively. MEptDA also shows dual-excitation mode with two excitation peaks at 330 nm and 395 nm, respectively. Thus, individual Ep, DA, and their mixture can be discriminated based on the different excitation spectral shapes and peak locations of PEp-PEI, PDA-PEI and MEptDA. Furthermore, the quantitative analysis of Ep and DA in mixture can also be achieved by switching excitation wavelength between 330 and 395 nm and monitoring the fluorescence emission intensity of MEptDA at 515 nm. The fluorescence intensity of MEptDA only related to the concentration of Ep when excited at 330 nm. Moreover, the concentration of DA can also be calculated by subtracting the fluorescence intensity of PEp-PEI from the total fluorescence intensity when excited at 395 nm. The resultant method has been used to simultaneously detect Ep and DA in human urine samples. The proposed fluorescence system is facile, eco-friendly, low-cost, and time-saving, and also provides a new and simple path for discriminating analogues.
关键词： Epinephrine,Fluorescence turn-on,Polyethyleneimine,Dopamine,Simultaneous discrimination and detection
更新于2025-09-23 15:23:52
-
Colorimetric detection of normetanephrine, a pheochromocytoma biomarker, using bifunctionalised gold nanoparticles
摘要： A simple and effective colorimetric method for the detection of normetanephrine (NMN), an O-methylated metabolite of norepinephrine, using functionalised gold nanoparticles is described. This metabolite is an important biomarker in the diagnosis of adrenal tumours such as pheocromocytoma or paraganglioma. The colorimetric probe consists of spherical gold nanoparticles (AuNPs) functionalised with two different ligands, which specifically recognize different functional groups in normetanephrine. Thus, a benzaldehyde-terminated ligand was used for the recognition of the amino alcohol moiety in NMN, by forming the corresponding oxazolidine. On the other hand, N-acetyl-cysteine was chosen for the recognition of the phenolic hydroxyl group through the formation of hydrogen bonds. The selective double molecular recognition between the probe and the hydroxyl and the amino-alcohol moieties of normetanephrine led to interparticle-crosslinking aggregation resulting in a change in the color of the solution, from red to blue, which could be observed by naked eye. The probe was highly selective towards normetanephrine and no color changes were observed in the presence of other neurotransmitter metabolites such as homovanillic acid (HVA) (dopamine metabolite), 5-hydroxyindoleacetic acid (5-HIAA) (serotonin metabolite), or other biomolecules present in urine such as glucose (Glc), uric acid (U.A), and urea. Finally, the probe was evaluated in synthetic urine with constituents that mimic human urine, where a limit of detection of 0.5 mM was achieved.
关键词： Gold nanoparticles,Aggregation,Pheocromocytoma,Normetanephrine,Colorimetric detection
更新于2025-09-23 15:23:52
-
Non-Invasive Optical Guided Tumor Metastasis/Vessel Imaging by Using Lanthanide Nanoprobe with Enhanced Down-Shifting Emission beyond 1500 nm
摘要： Visualization of tumor vessels/metastasis and cerebrovascular architecture is vital important for analyzing pathological states of brain diseases and tumor's abnormal blood vessel to improve cancer diagnosis. In vivo fluorescence imaging using second near infrared emission beyond 1500 nm (NIR-IIb) is emerged as a next generation optical imaging method with significant improvement in imaging sensitivity and spatial resolution. Unfortunately, highly biocompatible probe capable of generating NIR-IIb emission with sufficient brightness and uniformed size is still scarce. Here, we have proposed the polyacrylic acid (PAA)-modified NaLnF4:40Gd/20Yb/2Er nanorods (Ln=Y, Yb, Lu, PAA-Ln-NRs) with enhanced downshifting NIR-IIb emission, high quantum yield (QY), relative narrow bandwidth (~160 nm) and high bio-compatibility via Ce3+ doping for high performance NIR-IIb bioimaging. The downshifting emission beyond 1500 nm is improved by 1.75~2.2 times with simultaneously suppressing the upconversion (UC) path in Y, Yb, and Lu hosts via Ce3+ doping. Moreover, compared with the traditionally used Y-based host, the QY of NIR-IIb emission in Lu-based probe in water is improved from 2.2% to 3.6%. The explored bright NIR-IIb emitted PAA-Lu-NRs were used for high sensitivity small tumor (~ 4 mm)/metastatic tiny tumor detection (~ 3 mm), tumor vessel visualization with high spatial resolution (41 μm) and brain vessel imaging. Therefore, our findings open up the opportunity of utilizing lanthanide based NIR-IIb probe with bright 1525 nm emission for in vivo optical-guided tumor vessel/metastasis and non-invasive brain vascular imaging.
关键词： enhancement of downshifting emission,tiny metastatic tumor detection,tumor vascular imaging,rare-earth nanoprobes,brain vascular imaging
更新于2025-09-23 15:23:52
-
Ultrasensitive detection of miRNA with an antimonene-based surface plasmon resonance sensor
摘要： MicroRNA exhibits differential expression levels in cancer and can affect cellular transformation, carcinogenesis and metastasis. Although fluorescence techniques using dye molecule labels have been studied, label-free molecular-level quantification of miRNA is extremely challenging. We developed a surface plasmon resonance sensor based on two-dimensional nanomaterial of antimonene for the specific label-free detection of clinically relevant biomarkers such as miRNA-21 and miRNA-155. First-principles energetic calculations reveal that antimonene has substantially stronger interaction with ssDNA than the graphene that has been previously used in DNA molecule sensing, due to thanking for more delocalized 5s/5p orbitals in antimonene. The detection limit can reach 10 aM, which is 2.3–10,000 times higher than those of existing miRNA sensors. The combination of not-attempted-before exotic sensing material and SPR architecture represents an approach to unlocking the ultrasensitive detection of miRNA and DNA and provides a promising avenue for the early diagnosis, staging, and monitoring of cancer.
关键词： surface plasmon resonance,biosensor,antimonene,cancer diagnosis,miRNA detection
更新于2025-09-23 15:23:52
-
Red-emissive conjugated oligomer/silica hybrid nanoparticles with high affinity and application for latent fingerprint detection
摘要： Latent fingerprint detection plays a great role in forensic science, and considerable efforts have been made on developing efficient and simple strategy to realize clear visualization of latent fingerprints. Among them, fluorescent nanoparticles have attracted increasing interests due to their easy fabrication, good photostability, and low toxicity, but insufficient affinity toward fingerprints has limited their further application. Herein, we report a red-emissive conjugated oligomer/silica hybrid nanoparticle with enhanced affinity toward fingerprints, showing a promising performance on fluorescent detection on latent fingerprints. The conjugated oligomer is covalently doped into the silica nanoparticles, which effectively guarantee its fluorescent quantum yield and photostability. Moreover, the red emission of these nanoparticles also enables the latent fingerprint detection on substrates with fluorescent background, such as plastic and various papers. Most importantly, the introduction of epoxy groups on the silica surface largely enhances its affinity toward fingerprints, compared to that with hydroxy or amino groups, which possibly can be ascribed to its electrostatic attraction and hydrophobic interaction with amino acids and sebaceous substances of fingerprints, respectively.
关键词： Latent fingerprint detection,High affinity,Red emission,Fluorescence,Conjugated oligomer
更新于2025-09-23 15:23:52
-
A method for particulate matter 2.5 (PM2.5) biotoxicity assay using luminescent bacterium
摘要： The ability to analyze biotoxicity of atmospheric pollution plays an important role in public health. It provides the potential to directly analyze the health information of at-risk individuals. Although air quality standards have received significant attention in many countries, the potential for better biotoxicity assessment has remained largely unexplored. Here we propose a method using one kind of luminescent bacterium Photobacterium phosphoreum to detect the biotoxicity of atmospheric particulate matter ≤ 2.5 μm (PM2.5). Combined with the results of air pollution data of the year 2013–2014, this method has been proven to have good biotoxicity detection performance, and can evaluate the severity of at least 85% of PM2.5 related biotoxicity in Shanghai during this time period. Based on an established algorithm of this detection system, the biotoxicity of twelve PM2.5 real samples (collected over a month) were tested and divided into different biotoxicity levels. It allows an effective evaluation of biotoxicity of PM2.5 due to the quick and sensitive response of bioluminescence to the concentration of toxic components, which provides a valuable reference to evaluate the biotoxicity of PM2.5. This established method can be easily applied to the analysis and evaluation of any other PM2.5 samples assay by following the steps.
关键词： Atmospheric PM2.5,Public health,Photobacterium phosphoreum,Air pollution,Luminescent bacterium,Biotoxicity detection
更新于2025-09-23 15:23:52