scholarly journals A BTT-Based Colorimetric Dual Sensor for Hg(II) and Selected Anions with Molecular Logic Operations

2016 ◽  
Vol 2016 ◽  
pp. 1-11 ◽  
Author(s):  
Veikko Uahengo ◽  
Ping Cai ◽  
Likius S. Daniel
Keyword(s):  
Charge Transfer Band ◽  
Color Changes ◽  
H Nmr ◽  
Naked Eye ◽  
Molecular Logic ◽  
Dual Sensor ◽  
One Step ◽  
Anions And Cations ◽  
Logic Operations ◽  
Logic Functions

A benzotrithiophenes (BTT) based colorimetric sensor (2) was synthesized via a simple one-step reaction process, and its recognition properties towards several biologically important anions and cations were investigated by naked eye observation and spectroscopic methods of UV-vis and 1H NMR analysis in DMSO. The molar addition of anions such as F−, AcO−, and H2PO4- induced a marked red shift of the charge transfer band (Δλ=94 nm, from 440 nm to 534 nm) concomitant with a clearly visible “naked eye” detectable colorimetric activities (from orange to pink). However, the molar addition of H2PO4- did not induce significant spectral changes, compared to F− and AcO−. Furthermore, the molar addition of Hg2+ to 2 resulted in hypochromic shift at 440 nm and the eventual disappearance of a low energy band at 534 nm, concomitant with the colorimetric activities (from orange to yellow). Moreover, both spectral and color changes induced by the addition of anions (F− and AcO−) were all reversible by the molar addition of metal cations of 3d5–10. The reversibility properties triggered the logic operation studies, and, subsequently, the complementary IMP/INH logic functions based on color and spectral switching (ON/OFF) were confirmed. Conclusively, 2 can thus be utilized as a colorimetric molecular switch modulated by AcO−/MII.

scholarly journals Carbon Dots-Based Logic Gates

Nanomaterials ◽  
2021 ◽  
Vol 11 (1) ◽  
pp. 232
Author(s):  
Shweta Pawar ◽  
Hamootal Duadi ◽  
Yafit Fleger ◽  
Dror Fixler
Keyword(s):  
Amino Acids ◽  
Carbon Dots ◽  
Modern Science ◽  
Logic Gates ◽  
Fluorescence Techniques ◽  
Molecular Logic ◽  
Highly Sensitive ◽  
Different Types ◽  
Logic Operations ◽  
Logic Functions

Carbon dots (CDs)-based logic gates are smart nanoprobes that can respond to various analytes such as metal cations, anions, amino acids, pesticides, antioxidants, etc. Most of these logic gates are based on fluorescence techniques because they are inexpensive, give an instant response, and highly sensitive. Computations based on molecular logic can lead to advancement in modern science. This review focuses on different logic functions based on the sensing abilities of CDs and their synthesis. We also discuss the sensing mechanism of these logic gates and bring different types of possible logic operations. This review envisions that CDs-based logic gates have a promising future in computing nanodevices. In addition, we cover the advancement in CDs-based logic gates with the focus of understanding the fundamentals of how CDs have the potential for performing various logic functions depending upon their different categories.

Synthesis of new chromogenic sensors containing thiourea and selective detection for F–, H2PO4–, and Ac– anions

2020 ◽  
Vol 98 (10) ◽  
pp. 659-666
Author(s):  
Cheng Cao ◽  
Xingmei You ◽  
Lei Feng ◽  
Guanghong Luo ◽  
Guoren Yue ◽  
...  
Keyword(s):  
Anion Recognition ◽  
High Sensitivity ◽  
Eye Detection ◽  
H Nmr ◽  
Naked Eye ◽  
Step Procedure ◽  
Colour Changes ◽  
One Step ◽  
Naked Eye Detection ◽  
C Nmr

Two new chromogenic sensors 1-(2-hydroxyphenyl)-3-(4-nitrophenyl)thiourea 1 and 1-(3-hydroxypyridin-2-yl)-3-(4-nitrophenyl)thiourea 2 bearing nitrophenyl and thiourea groups were designed and synthesized by one-step procedure and characterized through 1H NMR, 13C NMR, FTIR, and MS. The anion recognition property of the receptors was studied via naked-eye detection, UV–vis, and 1H NMR. Based on the existence of amino gen and hydroxyl moieties in receptors, receptors 1 and 2 exhibit obvious selectivity by the redshift of UV–vis signals, colour changes through naked-eye detection, and binding effects for F–, H2PO4–, and Ac–. Surprisingly, the detection limits of receptor 1 for F– and Ac– were calculated to be 5.45 × 10−7 and 2.11 × 10−7 (mol/L)−1, respectively, which indicated that F– and Ac– can be identified with high sensitivity by receptor 1. Besides, simple “test strips” were developed and were used as sensors for recognition of F–, H2PO4–, or Ac– in DMSO solution. Lastly, the mechanisms of the recognition process were studied through DFT calculation and 1H NMR titration.

scholarly journals Effect of Citric Acid on Color Changes of Calcium Silicate-Based Cements an In Vitro Study

2021 ◽  
Vol 11 (5) ◽  
pp. 2339
Author(s):  
Joanna Metlerska ◽  
Till Dammaschke ◽  
Mariusz Lipski ◽  
Irini Fagogeni ◽  
Anna Machoy-Mokrzyńska ◽  
...  
Keyword(s):  
Citric Acid ◽  
Calcium Silicate ◽  
In Vitro Study ◽  
Vitro Study ◽  
Color Measurement ◽  
Color Changes ◽  
Naked Eye ◽  
Root Canal Irrigants ◽  
The Difference

The aim of the present in vitro study was to investigate the effects of 10% and 40% citric acid (CA) on the color of calcium silicate–based cements (CSCs) in comparison to the effects of common root canal irrigants. Samples of six CSCs (n = 6)—ProRoot MTA (Dentsply, Tulsa, OK, USA), Biodentine (Septodont, Saint-Maur-des-Fossés, France), MTA Plus (Avalon Biomed Inc, by Prevest Denpro Limited, Jammu, India), MTA Repair HP (Angelus, Londrina, PR, Brazil), Ortho MTA (BioMTA, Seoul, Korea), and Retro MTA (BioMTA, Seoul, Korea)—were immersed in 10% and 40% CA as well as 15% EDTA, 2% NaOCl, 2% CHX, and 0.9% NaCl for 15 min, 1 h, and 24 h. ΔE values, representing the difference between the final and baseline values of the color components, were then determined using a VITA Easyshade Compact 5.0 spectrophotometer. Naked-eye evaluation of the changes in color and structures of the materials was performed using our own scale. Upon immersion of the materials in both 10% and 40% CA, there were statistically significant differences between spectrophotometric color measurement results for all CSCs (P < 0.05). However, CA does not cause dark discoloration, observable with the naked eye, of any of the materials, such as NaOCl and CHX. Significant statistical differences were also found between all CSCs in terms of submersion duration (P < 0.05). CA, which could be an alternative to EDTA use, caused greater CSCs discoloration and changed some of their structures. Unless required by the therapeutic procedure, clinicians should pay attention to the fact that the irrigant may affect the CSCs discoloration and minimize the contact time of irrigant with CSCs.

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.

Matter, energy and information network of a graphene-peptide-based fluorescent sensing system for molecular logic computing, detection and imaging of cancer stem cell marker CD133 in cells and tumor tissues

The Analyst ◽  
2019 ◽  
Vol 144 (6) ◽  
pp. 1881-1891 ◽  
Author(s):  
Fu Rui Zhang ◽  
Jiao Yang Lu ◽  
Qing Feng Yao ◽  
Qiu Yan Zhu ◽  
Xin Xing Zhang ◽  
...  
Keyword(s):  
Stem Cell Marker ◽  
Information Network ◽  
Cancer Stem Cell Marker ◽  
Cell Marker ◽  
Fluorescent Sensing ◽  
Sensing System ◽  
Molecular Logic ◽  
Tumor Tissues ◽  
Logic Operations ◽  
Matter Energy

A graphene-peptide-based fluorescent sensing system for molecular logic operations, sensing and imaging of CD133.

scholarly journals Simple and Visible Detection of Novel Astroviruses Causing Fatal Gout in Goslings Using One-Step Reverse Transcription Polymerase Spiral Reaction Method

2020 ◽  
Vol 7 ◽  
Author(s):  
Jun Ji ◽  
Qinxi Chen ◽  
Zhengli Yu ◽  
Xin Xu ◽  
Xinhao Mu ◽  
...  
Keyword(s):  
Reverse Transcription ◽  
Cost Effective ◽  
Pcr Primers ◽  
Probit Regression ◽  
Conventional Pcr ◽  
Specific Detection ◽  
Isothermal Method ◽  
Naked Eye ◽  
One Step ◽  
The One

In this study, a one-step isothermal method combining polymerase spiral reaction (PSR) with reverse transcription (RT-PSR) was established for rapid and specific detection of novel astroviruses causing fatal gout in goslings (N-GoAstV). The one-step RT-PSR was accomplished at the optimal temperature of 62°C and time of 40 min and used primers simply designed as conventional PCR primers, and the results of detection were visible to the naked eye. The detection limit of PSR was above 34.7 copies/μL at a 95% probability level according to probit regression analysis. The assay specifically detected N-GoAstV, and no other reference viruses were detected. These results suggest that the newly established RT-PSR assay could, in one step, accomplish reverse-transcription, amplification, and result determination providing a visible, convenient, rapid, and cost-effective test that can be carried out onsite, in order to ensure timely quarantine of N-GoAstV-infected birds, leading to effective disease control.

scholarly journals A multi-colorimetric probe to discriminate between heavy metal cations and anions in DMSO–H2O with high selectivity for Cu2+ and CN−: study of logic functions and its application in real samples

RSC Advances ◽  
2021 ◽  
Vol 11 (47) ◽  
pp. 29466-29485
Author(s):  
Eunike Hamukwaya ◽  
Johannes Naimhwaka ◽  
Veikko Uahengo
Keyword(s):  
Heavy Metal ◽  
Schiff Base ◽  
Reaction Mechanism ◽  
High Selectivity ◽  
Colorimetric Probe ◽  
Real Samples ◽  
Heavy Metal Cations ◽  
H Nmr ◽  
Vis Spectroscopy ◽  
Logic Functions

A ditopic multi-colorimetric probe based on the phenylpridyl-thioic moiety (EN) was synthesized via a Schiff base reaction mechanism and characterized using 1H NMR and UV-vis spectroscopy.

scholarly journals Solvent Controlled Colorimetric And Fluorometric Detection of Fe2+ and Cu2+ Ions By Naphthaldimine-Glucofuranose Conjugate

2021 ◽  
Author(s):  
Mini Loya ◽  
Bholanath Dolai ◽  
Ananta Kumar Atta
Keyword(s):  
High Resolution Mass Spectrometry ◽  
Binding Mode ◽  
Fluorometric Detection ◽  
Nmr Titration ◽  
Fluorescence Studies ◽  
Color Changes ◽  
H Nmr ◽  
Absorption And Emission Spectroscopy ◽  
Absorbance Data ◽  
Metal Ligand

Abstract The sensing properties of naphthaldimine-glucofuranose conjugates 1 and 2 towards metal ions were investigated by 1H NMR titration, FTIR, absorbance, and fluorescence spectroscopic methods. The absorbance and fluorescence studies indicated that compound 1 formed coordination with Fe2+ and Cu2+ ions in DMSO through color changes yellow to brown and colorless, respectively. The Job's plots using absorbance data showed metal-ligand binding ratio is 1:1 for both cases. The formation of 1-Fe2+ and 1-Cu2+ complexes have been analyzed by absorption and emission spectroscopy, high-resolution mass spectrometry (HRMS) data, FTIR, 1H NMR titration experiment, and DFT calculations. The detection limits of naphthaldimine sugar conjugate 1 towards Fe2+/Cu2+ were calculated from UV-vis and fluorescence data according to the standard method. The sugar-naphthaldimine conjugate 2 has been used to establish the binding mode of 1 with Fe2+ or Cu2+ ions in DMSO.

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