scholarly journals An Acylhydrazone-Based Fluorescent Sensor for Sequential Recognition of Al3+ and H2PO4−

Materials ◽  
2021 ◽  
Vol 14 (21) ◽  
pp. 6392
Author(s):  
Donghwan Choe ◽  
Cheal Kim
Keyword(s):  
Fluorescence Quenching ◽  
Dft Calculations ◽  
1H Nmr ◽  
Fluorescent Sensor ◽  
Visible Spectroscopy ◽  
Nmr Titration ◽  
Esi Ms ◽  
1H Nmr Titration ◽  
Uv Visible ◽  
Sequential Recognition

A novel acylhydrazone-based fluorescent sensor NATB was designed and synthesized for consecutive sensing of Al3+ and H2PO4−. NATB displayed fluorometric sensing to Al3+ and could sequentially detect H2PO4− by fluorescence quenching. The limits of detection for Al3+ and H2PO4− were determined to be 0.83 and 1.7 μM, respectively. The binding ratios of NATB to Al3+ and NATB-Al3+ to H2PO4− were found to be 1:1. The sequential recognition of Al3+ and H2PO4− by NATB could be repeated consecutively. In addition, the practicality of NATB was confirmed with the application of test strips. The sensing mechanisms of Al3+ and H2PO4− by NATB were investigated through fluorescence and UV–Visible spectroscopy, Job plot, ESI-MS, 1H NMR titration, and DFT calculations.

scholarly journals An Indole-Based Fluorescent Chemosensor for Detecting Zn2+ in Aqueous Media and Zebrafish

Sensors ◽  
2021 ◽  
Vol 21 (16) ◽  
pp. 5591
Author(s):  
Donghwan Choe ◽  
Haeri So ◽  
Soyoung Park ◽  
Hangyul Lee ◽  
Ju Byeong Chae ◽  
...  
Keyword(s):  
Aqueous Media ◽  
Fluorescent Chemosensor ◽  
World Health ◽  
Visible Spectroscopy ◽  
Nmr Titration ◽  
Real Water Samples ◽  
1H Nmr Titration ◽  
The World ◽  
Uv Visible ◽  
Health Organization

An indole-based fluorescent chemosensor IH-Sal was synthesized to detect Zn2+. IH-Sal displayed a marked fluorescence increment with Zn2+. The detection limit (0.41 μM) of IH-Sal for Zn2+ was greatly below that suggested by the World Health Organization. IH-Sal can quantify Zn2+ in real water samples. More significantly, IH-Sal could determine and depict the presence of Zn2+ in zebrafish. The detecting mechanism of IH-Sal toward Zn2+ was illustrated by fluorescence and UV–visible spectroscopy, DFT calculations, 1H NMR titration and ESI mass.

scholarly journals A Novel Thiosemicarbazide-Based Fluorescent Chemosensor for Hypochlorite in Near-Perfect Aqueous Solution and Zebrafish

Chemosensors ◽  
2021 ◽  
Vol 9 (4) ◽  
pp. 65
Author(s):  
Minji Lee ◽  
Donghwan Choe ◽  
Soyoung Park ◽  
Hyeongjin Kim ◽  
Soomin Jeong ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Reactive Oxygen Species ◽  
Aqueous Solution ◽  
Fluorescence Quenching ◽  
Limit Of Detection ◽  
Fluorescent Sensor ◽  
Ionization Mass ◽  
Oxygen Species ◽  
Marked Selectivity ◽  
Uv Visible

A novel thiosemicarbazide-based fluorescent sensor (AFC) was developed. It was successfully applied to detect hypochlorite (ClO−) with fluorescence quenching in bis-tris buffer. The limit of detection of AFC for ClO− was analyzed to be 58.7 μM. Importantly, AFC could be employed as an efficient and practical fluorescent sensor for ClO− in water sample and zebrafish. Moreover, AFC showed a marked selectivity to ClO− over varied competitive analytes with reactive oxygen species. The detection process of AFC to ClO− was illustrated by UV–visible and fluorescent spectroscopy and electrospray ionization–mass spectrometry (ESI–MS).

scholarly journals Selective Colorimetric Sensors for Cyanide and Acetate Ion in Partially Aqueous Medium

2018 ◽  
Author(s):  
Divya Singhal ◽  
Neha Gupta ◽  
Ashok Kumar Singh
Keyword(s):  
Detection Limit ◽  
Aqueous Medium ◽  
1H Nmr ◽  
Binding Constant ◽  
High Selectivity ◽  
Good Sensitivity ◽  
Dft Studies ◽  
Nmr Titration ◽  
1H Nmr Titration ◽  
Nanomolar Detection

4-(thiazol-2-yldiazenyl)phenol (L1) and 2-((4-hydroxyphenyl) diazenyl)-5-nitrophenol (L2) based on azo phenol were synthesised and used as selective colorimetric sensor for CN- and AcO− ion in DMSO/H2O-HEPES (v/v; 1:1, pH–7.3 ± 0.2) and showed good sensitivity with large red shifts and nanomolar detection limit for CN- and AcO- ion. The stoichiometry of L1 with CN−/AcO− ion was found to be 1:1 and L2 with CN−/AcO− ion was found to be 1:2. Binding constant for L1+ CN−, L1 + AcO−, L2 + CN− and L2 + AcO− were calculated by B-H plot as 1.6 × 103, 8.0 × 102, 8.4 × 103 and 1.7 × 102 respectively. L2 showed high selectivity towards CN− ion with low detection limit of 81 nM and large binding constant. In addition, 1H NMR titration and DFT studies also supported the deprotonation mechanism of receptors in the presence of selective anions.

Determination of Tannin in Coffee Pulp Using Experimental and Theoritical Approches

2017 ◽  
Vol 751 ◽  
pp. 683-688
Author(s):  
Waleepan Rakitikul
Keyword(s):  
Electronic Structure ◽  
Dft Calculations ◽  
Structure Calculation ◽  
Electronic Structure Calculation ◽  
Visible Spectroscopy ◽  
Coffee Pulp ◽  
Soil Nutrition ◽  
Uv Visible ◽  
Homo Lumo

Currently, Doi Chaang village is the biggest area producing coffee in Thailand. Throughout seed to cup the pulp must be removed from coffee cherry after harvesting and left as waste. Tannin is one of various composition in coffee pulp which is affected by soil nutrition and pH. In this study, we have characterized the amount of tanin in coffee pulp using UV-Visible spectroscopy and electronic structure calculation. The results showed that coffee pulp consist of 5.68% tannin . It was determined to condense tannin form. Moreover, the pH of soil after treated with modified coffee pulp with water, Ca(OH)2, Na2S2O5, 2% Ca(OH)2, and 2% Na2S2O5 is higher than that with non-modified case. Likewise, DFT calculations predicted the structure of tannin with smaller HOMO-LUMO gap in the condense tannin.

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