- 标题
- 摘要
- 关键词
- 实验方案
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A new strategy for utilizing activated CH-group to construct a FRET platform for ratiometric sensing of cyanides
摘要： A fluorescent and colorimetric cyanide sensor (4-Br) based on the activated C-H group to construct a FRET platform has been described for the first time, along with demonstration of selective and reversible detection of cyanides through it. The sensing mechanism of 4-Br is an integration of ICT and FRET mechanisms, based on the deprotonation of the activated C-H group. Importantly, it is suitable for fluoresence imaging of cyanides in living cell.
关键词： Fluorescent probe,Colorimetric,FRET,ratiometric,Cyanide
更新于2025-09-10 09:29:36
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A smartphone-assisted microfluidic chemistry analyzer using image-based colorimetric assays for multi-index monitoring of diabetes and hyperlipidemia
摘要： A smartphone-assisted microfluidic chemistry analyzer using an image-based colorimetric detection method was successfully developed for the simultaneous analysis of three diabetes- and hyperlipidemia-related indexes, glucose (GLU), triglyceride (TG), and total cholesterol (TC). A fan-shaped microfluidic chip was designed and optimized to reliably allocate a premixed serum sample into four reaction chambers with a simple pipetting. The color changes of the peroxidase-H2O2 enzymatic reactions in the chambers were captured and analyzed using a smartphone-controlled analyzer with a LED light source and a CCD camera. The highly quantitative relationships between the analyte concentrations and the color characteristic values of the green channel of the captured images were successfully established, enabling accurate and reproducible detections of GLU, TG, and TC simultaneously at a low cost. The parallel analyses of 111 serum samples using our system and the conventional chemistry analyzer were conducted, yielding an excellent correlation and consistency between these two methods. This study proved the feasibility of performing the multi-index monitoring of diabetes, hyperlipidemia, and other chronic diseases on a POCT platform at a high fidelity, but a low cost.
关键词： Point-of-care testing,Smartphone,Colorimetric detection,Microfluidics,Multi-index analysis
更新于2025-09-10 09:29:36
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β-Cyclodextrin protected gold nanoparticle based cotton swabs as an effective candidate for specific sensing of trace levels of cyanide
摘要： In recent work, we demonstrate a rapid colorimetric and easy visual determination of cyanide ions (CNˉ ions) in water based on gold nanoparticles stabilized with β-cyclodextrin (β-CD). Optical detection of CNˉ ions were carried out using β-CD-AuNPs by tracking the changes in the SPR band and colorimetric nature of the β-CD AuNPs. This colorimetric nanosensor capably and ultra sensitively distinguishes the CNˉ ions owing to the capacity of etching the β-CD AuNPs surface and form a stable water soluble Au-CN complex. Under investigational conditions, the colorimetric assay demonstrated a steady response for CNˉ ions over a concentration arrays from 4.50 × 10-6 to 99.00 × 10-6 mol dm-3 with R = 0.994. Lowest limit of detection of this economical, naked eye visual approach is 93.00 × 10-9 mol dm-3, which is under the tolerant limit value (1.90 × 10-6 mol dm-3) described by the World health organization in drinking water. Specificity of β-CD-AuNPs based optical platform for the detection of CNˉ ions is superb evaluated with the various potential interfering anions. Furthermore, the proposed β-CD-AuNPs nanoprobe is effectively applied to quantify the CNˉ ions in tap and drinking water samples. For convenient use, we have designed a very stable β-CD-AuNPs containing cotton swab and it revealed good sensitivity against CNˉ ions in the environment with only bare eye.
关键词： cotton swab,Colorimetric analysis,drinking water samples,cyanide ions,nanosensor
更新于2025-09-10 09:29:36
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A multichannel Au nanosensor for visual and pattern inspection of fatty acids
摘要： Fatty acids (FAs) are important dietary sources of fuel for animals and structural components for cells. The number, position and configuration of olefins in the alkyl chains play important roles in the impacts of FAs on human health. Currently, structural profiling of FAs in edible oils and fats is an important issue in nutrition industries and food safety. Due to the lack of distinct functional groups, it is extremely difficult to discriminate FAs with structural difference by facile and in situ sensing methods. A few chemosensors have been developed for shape selective sensing of FAs, but their capability and performance were still limited. Herein, for the first time, we proposed a multichannel Au nanosensor for visual and pattern-generating inspection of FAs based on the highly selective binding ability of Ag+ to olefinic bonds and Ag+ regulable color variation of Au nanoparticles. As a result, the nanosensor showed good selectivity for five FAs with subtle structural difference as low as 5 nM. By further deriving three channel signals in respect of color and color depth, a signature-like signal pattern could be generated by principal component analysis for each FAs and even different FAs mixtures such as edible oils. Hence, structural variation of FAs in edible hot pot oils with heat treatment was successfully monitored by this Au nanosensor in time course. This sensor holds great promise in point-of-care inspection of edible oils and fats.
关键词： Au nanosensor,Colorimetric sensing,Pattern recognition,Edible oils,Fatty acids
更新于2025-09-09 09:28:46
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Colorimetric detection of cysteine based on dispersion - aggregation of chitosan stabilized gold nanoparticles
摘要： A simple and selective colorimetric method of detection of cysteine using chitosan stabilized gold nanoparticles has been developed. L-cysteine is a sulfur containing amino acid. Cysteine binds with the gold nanoparticles through sulfur group and induces aggregation of the nanoparticles which leads to an apparently visible color change from pale red to blue. A good linearity was observed from 0.1 to 30 μM (R=0.9958) cysteine and the limit of detection was found to be 0.1 μM. The gold nanoparticles showed a high selectivity towards the detection of cysteine even in the presence of 10,000 fold higher concentration of common interferences such as glutathione, methionine and homocysteine. A plausible mechanism for the selective detection of cysteine in presence of interferences based on a dispersion-aggregation mechanism has been proposed.
关键词： Sensitivity,Chitosan,Gold nanoparticles,Colorimetric sensor,Cysteine
更新于2025-09-09 09:28:46
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Colorimetric and NIR fluorescence probe with multiple binding sites for distinguishing detection of Cys/Hcy and GSH in vivo
摘要： Although some progress has been made in distinguishing detection of biothiols, NIR biothiol fluorescent probes for simultaneous distinguishing detection of Cys, Hcy and GSH in vivo have not been reported. The design of these probes involves the introduction of NIR fluorophores and multiple binding sites, so the integrated design of probes remains a challenge. Although Cys, Hcy and GSH have the common functional group: a sulfydryl group and an amino group, due to their differences in spatial structure, they may react with multiple binding sites probes to produce different reaction products in different bonding mechanisms, resulting in the different colors and fluorescent signals changes of the system. Therefore, multiple binding sites fluorescent probes can realize their discrimination detection. For NIR fluorescent probe, it is easier to realize in vivo imaging to promote the research of biothiols in clinical diagnosis. In our work, not only multiple binding sites were constructed in the compound, but also NIR fluorophores were introduced. This enables the probe to not only efficiently distinguish detection of Cys/Hcy and GSH but also achieve fluorescence imaging in vivo. We believe this result is a milestone in the discrimination detection of biothiols.
关键词： Cys/Hcy,in vivo,NIR fluorescence probe,GSH,Colorimetric,multiple binding sites
更新于2025-09-09 09:28:46
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Effect of Defects on Diffusion Behaviors of Lithium-ion Battery Electrodes: In Situ Optical Observation and Simulation
摘要： Lithium-ion batteries (LIBs) with high energy efficiency are urgeniltly needed in various fields. For the LIBs electrodes, defects would be generated during manufacture processes and mechanical degradation, and the defects significantly impact the stability and performance of LIBs. However, the effects of electrode defects on the electrochemical processes are still not clear. Herein, an in situ optical observation system is developed for monitoring the Li diffusion around the pre-introduced defects in the commercial graphite electrodes. The experiments show the gas-filled defects vertical to the direction of the Li diffusion would obviously decelerate Li diffusion, while the electrolyte-filled defects parallel to the direction of the Li diffusion would accelerate Li diffusion. In addition, finite element analysis (FEA) suggests consistent with the experiments, showing nonuniform distribution of local Li concentration around the defect. The equivalent diffusivity obtained by FEA is also dependent on the configuration of the defects. The diffusivities of electrolyte-filled parallel defect and gas-filled vertical defect are 12.6 % and 11.0 %, respectively. For the gas-filled defects, the size-effect calculation manifests that equivalent diffusivity would decrease with the enlarged defect size, and the shape of the defects would substantially impact the decrease rate. The results directly reveal the mechanisms of defect induced diffusion behavior change in the electrodes by the new equivalent 2D experiments, and the equivalent diffusivity would be useful for optimizing electrode designs in LIBs.
关键词： colorimetric method,defect,graphite anode,lithium-ion battery,diffusion
更新于2025-09-09 09:28:46
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A novel colorimetric and ratiometric fluorescent probe for selective detection of bisulfite in real samples and living cells
摘要： An abnormal level of bisulfite can induce toxicological effects associated with lung cancer, cardiovascular and neurological disorders. Therefore, it is of significance to develop an effective fluorescent probe to detect bisulfite in living cells. Herein, a novel fluorescent probe QPCT, based on a 1,4-addition mechanism, was constructed for the colorimetric and ratiometric detection of bisulfite. QPCT displayed high selectivity and anti-interference ability to bisulfite over other anions and biothiols. The probe renders a sensitive ratiometric response to bisulfite with a remarkable fluorescence blue shift from 590 to 537 nm and the fluorescence ratio was linear with bisulfite concentration over the range of 0-120 μM. More importantly, QPCT has been successfully applied to detect bisulfite in sugars and living A549 cells, which indicated that QPCT had a great capability for monitoring bisulfite in complex systems.
关键词： Real samples,Fluorescent probe,Live-cell imaging,Bisulfite,Colorimetric and ratiometric
更新于2025-09-09 09:28:46
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Optical sensing platform for colorimetric determination of silver nanoprisms and its application for hydrogen peroxide and glucose detections using a mobile device camera
摘要： Silver nanoprisms (AgNPrs) have a unique localized surface plasmon resonance, resulting in strong absorption and scattering within the visible light region. In this work, we propose the image acquisition from colloidal solutions of AgNPrs using a combination of transmitted and scattering lights. The developed measurement technique could be carried out by separately recording transmitted and scattering images of the solutions, using a mobile device camera prior to calculation of empirical absorption value (IA). IA value of green for AgNPrs solutions was found in agreement with the absorption spectra obtained using a conventional spectroscopic technique. This technique was utilized for the quantifications of hydrogen peroxide and glucose. The good linearities between ΔIA and those typical analytes were observed. The limit of detection for typical biosensor of glucose was 19.8 μM. As such, we expect the methodology herein developed for hydrogen peroxide and glucose determinations by means of monitoring the color change of transmitted and scatting images from solutions, to contribute to the development of simple, rapid, and reliable detection systems to be further applied in biochemical analysis and clinical diagnosis, as well as in household biosensor applications.
关键词： silver nanoprisms,glucose sensor,hydrogen peroxide sensor,localized surface plasmon resonance,colorimetric method
更新于2025-09-09 09:28:46
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Colorimetric-Fluorescent-Magnetic Nanosphere-Based Multimodal Assay Platform for Salmonella Detection
摘要： Rapid and sensitive foodborne pathogen detection assay, which can be applied in multiple fields, is essential to timely diagnosis. Herein, we proposed a multi-signal readout lateral flow immunoassay for Salmonella typhimurium (S. typhi) detection. The assay employs colorimetric-fluorescent-magnetic nanospheres (CFMNs) as labels, which possess multi-functional: target separation and enrichment, multi-signal readout and two formats of quantitation. The assay for S. typhi detection involves magnetic separation and chromatography. First, the S. typhi were separated and enriched from matrix by antibody labelled CFMNs, and then the S. typhi-containing suspension is added onto the sample pad to flow up the test strip. The introduction of magnetic separation enhances anti-interference ability and 10-fold sensitivity, making the assay possible for practical application. The assay has realized naked eye detection of 1.88×104 CFU/mL S. typhi, and 3.75×103 CFU/mL S. typhi can be detected with a magnetic assay reader, which is 2–4 orders of magnitude lower than other label-based LFIAs, with a quantitation range of 1.88×104 to 1.88×107 CFU/mL by measuring the fluorescence intensity and magnetic signal. Moreover, the successful detection of S. typhi in complex matrix (tap water, milk, fetal bovine serum and whole blood) indicated its potential application in real samples.
关键词： colorimetric-fluorescent-magnetic nanospheres,lateral flow immunoassay,Salmonella typhimurium,multimodal assay,pathogen detection
更新于2025-09-09 09:28:46