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.

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.

Silver nanoparticles as highly efficient and selective optical probe for sulphide via dendrimer formation in aqueous medium

RSC Advances ◽  
2016 ◽  
Vol 6 (18) ◽  
pp. 14563-14569 ◽  
Author(s):  
Isha Sanskriti ◽  
K. K. Upadhyay
Keyword(s):  
Silver Nanoparticles ◽  
Detection Limit ◽  
Aqueous Medium ◽  
Optical Probe ◽  
Colorimetric Sensor ◽  
Highly Efficient ◽  
Nanomolar Detection

1-[(4-Nitrophenyl)azo]-2-naphthol capped AgNPs were evaluated as a colorimetric sensor for S2− in aqueous medium over pH 4 to 10 with a nanomolar detection limit. The TEM, SEM and AFM images revealed the transition of spherical AgNPs into dendrimers.

scholarly journals Design, Synthesis, and Evaluation of New Colorimetric Chemosensors Containing Quinazolinones Moiety for some Cations Detection in an Aqueous Medium and Biological Sample

2021 ◽  
Vol 65 (3) ◽  
Author(s):  
Ayman. M. Algohary ◽  
Mohamed Hassan ◽  
Sami G. Almalki ◽  
Esam S. Al-Malki
Keyword(s):  
Aqueous Medium ◽  
1H Nmr ◽  
13C Nmr ◽  
Biological Sample ◽  
High Selectivity ◽  
Hydroxylamine Hydrochloride ◽  
Design Synthesis ◽  
Colorimetric Response ◽  
Nitrogen Nucleophiles ◽  
New Compounds

Abstract. The current project deals with designing and synthesizing of colorimetric chemosensors to detect the cations in the aqueous medium and biological sample. To achieve this goal a new series of quinazolinone derivatives were synthesized via reaction of the novel 6-nitro-2-propyl-4H-benzo[d][1,3]oxazin-4-one (3) with selected nitrogen nucleophiles, namely, formamide, hydrazine hydrate, hydroxylamine hydrochloride, O-phenylendiamine, O-aminophenol and O-aminothiophenol, urea and/or thiourea. Structures of the new compounds have been investigated depending on their spectral data (IR, 1H NMR, 13C NMR and MS) and elemental analyses. Some of the newly synthesized products exhibited a significant response as chemosensors for some cations detection. The synthesized chemosensors 11a and 11b showed high-selectivity and specificity towards cooper (CuII) and mercury (HgII) cations detection through exhibiting colormetric responses. Chemosensors 7 and 10b showed high selectivity toward cadmium (CdII) cation, whilst other examined compounds (9b, c, 10a, 12, 13, and 14) did not exhibit colorimetric response in all cation's samples.   Resumen. En el presente proyecto se diseñan y sintetizan quimiosensores colorimétricos para detectar los cationes en el medio acuoso y en la muestra biológica. Para lograr este objetivo se sintetizó una nueva serie de derivados de quinazolinona mediante la reacción de la 6-nitro-2-propil-4H-benzo[d][1,3]oxazin-4-ona (3) con nucleófilos nitrogenados seleccionados, a saber, formamida, hidrato de hidracina, clorhidrato de hidroxilamina, O-fenilendiamina, O-aminofenol y O-aminotiofenol, urea y/o tiourea. Las estructuras de los nuevos compuestos se han comprobado en función de sus datos espectrales (IR, 1H NMR, 13C NMR y MS) y de los análisis elementales. Algunos de los nuevos productos sintetizados mostraron una respuesta significativa como quimiosensores para la detección de algunos cationes. Los quimiosensores sintetizados 11a y 11b mostraron una alta selectividad y especificidad hacia la detección de los cationes cobre (Cu II) y mercurio (Hg II) al mostrar respuestas colormétricas. Los quimiosensores 7 y 10b mostraron una alta selectividad hacia el catión cadmio (Cd II), mientras que otros compuestos examinados (9b, c, 10a, 12, 13 y 14) no mostraron respuesta colorimétrica con los cationes investigados.

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