Highly sensitive and selective “naked eye” sensing of Cu(ii) by a novel amido–imine based receptor: a spectrophotometric and DFT study with practical application

RSC Advances ◽  
2016 ◽  
Vol 6 (34) ◽  
pp. 28194-28199 ◽  
Author(s):  
Arghyadeep Bhattacharyya ◽  
Soumen Ghosh ◽  
Nikhil Guchhait
Keyword(s):  
Aqueous Medium ◽  
Color Change ◽  
Dft Study ◽  
Practical Application ◽  
Naked Eye ◽  
Highly Sensitive

Synthesis of (E)-bis-N'-((1H-pyrrol-2-yl)-methylene)-pyridine-2,6-carbohydrazide and its sensing ability towards copper(ii) ion in aqueous medium by color change, the sensing limit being 4.0 × 10−9 M.

Highly sensitive and selective colorimetric naked-eye detection of Cu2+ in aqueous medium using a hydrazone chemosensor

2015 ◽  
Vol 215 ◽  
pp. 241-248 ◽  
Author(s):  
Shengli Hu ◽  
Jingjing Song ◽  
Fang Zhao ◽  
Xianggao Meng ◽  
Gongying Wu
Keyword(s):  
Aqueous Medium ◽  
Eye Detection ◽  
Naked Eye ◽  
Highly Sensitive ◽  
Naked Eye Detection

scholarly journals Efficient Colorimetric Fluoride Anion Sensor Based on π-Conjugated Carbazole Small Molecule

2021 ◽  
Vol 9 ◽  
Author(s):  
Zhifeng Deng ◽  
Cheng Wang ◽  
Junqiang Li ◽  
Meng Zheng
Keyword(s):  
Color Change ◽  
Organic Dyes ◽  
High Sensitivity ◽  
Proton Nuclear Magnetic Resonance ◽  
Fluoride Anion ◽  
Naked Eye ◽  
Intermolecular Proton Transfer ◽  
Highly Sensitive ◽  
First Time ◽  
Tetrahydrofuran Solution

The ability to detect fluoride anions with high selectivity and sensitivity by using the naked eye is crucial yet challenging. In this study, a novel, simple conjugated organic dye, N-tert-butyldimethylsilyl-3,6-diiodocarbazole (CA-TBMDS) was developed and used for the first time as a colorimetric sensor for fluoride. CA-TBMDS was found to be a highly sensitive fluoride chemosensor, with a detection limit as low as 3 × 10−5 M. The reaction of CA-TBMDS with fluoride anions in a tetrahydrofuran solution resulted in a color change from colorless to yellow under ambient light, which can be discriminated by the naked eye. The sensor operated via intermolecular proton transfer between the amide units and the fluoride anion, as confirmed by proton nuclear magnetic resonance titration. CA-TBMDS is not only highly sensitive to fluoride anions, but also exhibits high sensitivity in the presence of various ions. This work demonstrates that N-butyldimethylchlorosilane-based organic dyes have prospective utility as a type of fluoride anion chemosensor.

scholarly journals Aptamer-Based Colorimetric Probe for trans-Zeatin Detection Using Unmodified Gold Nanoparticle

2020 ◽  
Vol 2020 ◽  
pp. 1-7
Author(s):  
Ping Sun ◽  
Xiwei Zhang ◽  
Xianxiang Wang
Keyword(s):  
Color Change ◽  
Colorimetric Method ◽  
High Concentration ◽  
Complementary Dna ◽  
Naked Eye ◽  
Double Stranded Dna ◽  
Highly Sensitive ◽  
Structure Switching ◽  
Corn Kernels ◽  
Aptamer Sequence

Trans-Zeatin is the major active phytohormone in immature corn kernels. Herein, a highly sensitive, good selective and simple aptamer-based colorimetric method for the detection of trans-zeatin was constructed. The selected aptamer sequence binds with trans-zeatin and induces a duplex-to-aptamer structure switching. The gold nanoparticles (AuNPs) solution is stable with high-concentration salt, which is protected by red complementary DNA. In the absence of trans-zeatin, the color of AuNPs changed from red to blue because aptamer DNA and complementary DNA form double-stranded DNA. Thus, the ratio of absorbance intensities (A522/A650) of AuNPs is changed with the concentration of trans-zeatin. The color change could be observed by the naked eye. The linear range of this method covers a large variation of trans-zeatin concentration from 0.05 to 0.75 μM. The detection limit is 0.037 μM. Moreover, this method was applied successfully to detect trans-zeatin in real plant samples.

scholarly journals A Facile Strategy for Immobilizing GOD and HRP onto Pollen Grain and Its Application to Visual Detection of Glucose

2020 ◽  
Vol 21 (24) ◽  
pp. 9529
Author(s):  
Shanxia Jin ◽  
Liping Liu ◽  
Mengying Fan ◽  
Yaru Jia ◽  
Ping Zhou
Keyword(s):  
Visual Detection ◽  
Color Change ◽  
Cost Effective ◽  
Pollen Grain ◽  
Practical Application ◽  
Horse Radish Peroxidase ◽  
Experimental Conditions ◽  
Naked Eye ◽  
Cost Effective Approach ◽  
Affinity Interaction

Pollen grain was explored as a new carrier for enzyme immobilization. After being modified with boric acid-functionalized titania, the pollen grain was able to covalently immobilize glycosylated enzymes by boronate affinity interaction under very mild experimental conditions (e.g., pH 7.0, ambient temperature and free of organic solvent). The glucose oxidase and horse radish peroxidase-immobilized pollen grain became a bienzyme system. The pollen grain also worked as an indicator of the cascade reaction by changing its color. A rapid, simple and cost-effective approach for the visual detection of glucose was then developed. When the glucose concentration exceeded 0.5 mM, the color change was observable by the naked eye. The assay of glucose in body fluid samples exhibited its great potential for practical application.

Design and synthesis of new tripod-chromogenic sensor based on s-triazine and thiazolidine-2,4-dione ring (TCST) for naked-eye detection of Li+

2021 ◽  
Author(s):  
Hadiseh Yazdani Nyaki ◽  
Nosrat Mahmoodi ◽  
Meysam Pasandideh Nadamani
Keyword(s):  
Color Change ◽  
Biological Activities ◽  
Central Nucleus ◽  
Eye Detection ◽  
Design And Synthesis ◽  
Naked Eye ◽  
1H Nmr Titration ◽  
Highly Sensitive ◽  
Different Color ◽  
Naked Eye Detection

A novel tripod-chromogenic sensor contains central nucleus s-triazine and thiazolidine-2,4-dione ring (TCST) was designed, synthesized and applied as colorimetric probes in aqueous solutions of dimethyl sulfoxide (DMSO). The probe showed a highly sensitive and selective colorimetric sensor for naked-eye detection of Li+, with a different color change from colorless to yellow. The probe’s detection limit (LOD) toward Li+ was found to be 1.2 μM. The result of the Job’s plot showed 1:1 stoichiometry for the interaction between tripod-chemosensor and Li+ that this result was confirmed by 1H NMR titration experiments. The probe can also be used for biological activities depending on the results of microbial tests.

scholarly journals Development of a highly sensitive point-of-care test to detect SARS-CoV-2 from saliva combining a simple RNA extraction method with colorimetric reverse transcription loop-mediated isothermal amplification detection

2020 ◽  
Author(s):  
Wataru Yamazaki ◽  
Yasufumi Matsumura ◽  
Uraiwan Thongchankaew-Seo ◽  
Yasuko Yamazaki ◽  
Miki Nagao
Keyword(s):  
Reverse Transcription ◽  
Extraction Method ◽  
Color Change ◽  
Point Of Care ◽  
Rna Extraction ◽  
Reference Standard ◽  
Diagnostic Specificity ◽  
Naked Eye ◽  
Point Of Care Test ◽  
Highly Sensitive

AbstractTo diagnose COVID-19 patients in the field, a sensitive point-of-care test using saliva was developed. Using a heat block without centrifuge, the test took 45 minutes. Naked eye judgement with color change dye outperformed the reference standard, with a diagnostic sensitivity of 82.6% (19/23) and diagnostic specificity of 100% (21/21).

Dimalononitrile-containing probe based on aggregation-enhanced emission features for the multi-mode fluorescence detection of volatile amines

2017 ◽  
Vol 196 ◽  
pp. 101-111 ◽  
Author(s):  
Lingwei Kong ◽  
Yahui Zhang ◽  
Huiling Mao ◽  
Xiaoling Pan ◽  
Yong Tian ◽  
...  
Keyword(s):  
Fluorescence Detection ◽  
Color Change ◽  
Limit Of Detection ◽  
Uv Light ◽  
Real Life ◽  
High Sensitivity ◽  
Naked Eye ◽  
Highly Sensitive ◽  
Multi Mode ◽  
Volatile Amines

A novel multi-mode probe consisting of a hexaphenyl-1,3-butadiene derivative, 2,2′-((((1Z,3Z)-1,2,3,4-tetraphenylbuta-1,3-diene-1,4-diyl)bis(4,1-phenylene))bis(methanylylidene))dimalononitrile (ZZ–HPB–CN), with typical aggregation-enhanced emission (AEE) features was easily prepared for the highly sensitive and rapid detection of amine vapors. The ZZ–HPB–CN sensor, which was prepared by simply depositing ZZ–HPB–CN on filter paper, could detect low concentration vapors of volatile amines using fluorescence, ultraviolet and naked-eye detection. The limit of detection of the sensor was as low as 1 ppb for the fluorescence detection. The color change of the sensor caused by 1–10 ppm amine vapors could be observed under UV light or with the naked eye. The high sensitivity, quick response and easy operation of the probe give it great potential for real-life applications.

scholarly journals Recent Advancements in Enzyme-Based Lateral Flow Immunoassays

Sensors ◽  
2021 ◽  
Vol 21 (10) ◽  
pp. 3358
Author(s):  
Donato Calabria ◽  
Maria Maddalena Calabretta ◽  
Martina Zangheri ◽  
Elisa Marchegiani ◽  
Ilaria Trozzi ◽  
...  
Keyword(s):  
Lateral Flow ◽  
Qualitative Information ◽  
Eye Color ◽  
Commercial Success ◽  
Color Changes ◽  
Naked Eye ◽  
Future Developments ◽  
Highly Sensitive ◽  
Critical Overview ◽  
Detection Technologies

Paper-based lateral-flow immunoassays (LFIAs) have achieved considerable commercial success and their impact in diagnostics is continuously growing. LFIA results are often obtained by visualizing by the naked eye color changes in given areas, providing a qualitative information about the presence/absence of the target analyte in the sample. However, this platform has the potential to provide ultrasensitive quantitative analysis for several applications. Indeed, LFIA is based on well-established immunological techniques, which have known in the last year great advances due to the combination of highly sensitive tracers, innovative signal amplification strategies and last-generation instrumental detectors. All these available progresses can be applied also to the LFIA platform by adapting them to a portable and miniaturized format. This possibility opens countless strategies for definitively turning the LFIA technique into an ultrasensitive quantitative method. Among the different proposals for achieving this goal, the use of enzyme-based immunoassay is very well known and widespread for routine analysis and it can represent a valid approach for improving LFIA performances. Several examples have been recently reported in literature exploiting enzymes properties and features for obtaining significative advances in this field. In this review, we aim to provide a critical overview of the recent progresses in highly sensitive LFIA detection technologies, involving the exploitation of enzyme-based amplification strategies. The features and applications of the technologies, along with future developments and challenges, are also discussed.

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