A phthalocyanine-based fluorescent sensor for Zn2+ ion

2013 ◽  
Vol 17 (01n02) ◽  
pp. 99-103 ◽  
Author(s):  
Hui He ◽  
Jian-Yong Liu ◽  
Dennis K.P. Ng
Keyword(s):  
Metal Ions ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Near Infrared ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Absorption And Fluorescence Spectra

This paper describes the preparation and spectral properties of a near-infrared fluorophore in which two bis(2-picolyl)amino moieties are axially linked to a silicon(IV) phthalocyanine core. The effects of various metal ions on its absorption and fluorescence spectra have been examined. The results indicate that this compound shows a high sensitivity and moderate selectivity toward Zn2+ ion.

Electronic absorption and fluorescence spectra of 2-phenyl-substituted benzothiazoles: study of excited-state proton transfer reactions

1991 ◽  
Vol 69 (10) ◽  
pp. 1539-1547 ◽  
Author(s):  
Joykrishna Dey ◽  
Sneh K. Dogra
Keyword(s):  
Proton Transfer ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Transfer Reactions ◽  
Ionization Constants ◽  
Dilute Acid ◽  
Absorption And Fluorescence Spectra ◽  
Charge Densities ◽  
Proton Transfer Reactions ◽  
Fluorimetric Titration

The absorption and fluorescence spectral properties of 2-(3′-hydroxyphenyl)-, 2-(4′-hydroxyphenyl)-, and 2-(3′,4′-dihydroxyphenyl)-, and 2-(4′-hydroxy-3′-methoxyphenyl), 2-(3′-hydroxy-4′-methoxyphenyl)-, and 2-(3′-methoxyphenyl)benzothiazoles have been studied in a number of solvents of varying polarity. The ionization constants (pKa) for various prototropic reactions of these molecules in both S0 and S1 states are determined. The effect of substitution on the spectral properties and on the pKa values are discussed. The molecules have been found to undergo biprotonic phototautomerism in dilute acid solutions. On the basis of the fluorimetric titration behaviour of the molecules (except 2-(3′-methoxyphenyl)benzothiazole), the existence of monocation–zwitterion equilibrium in the S1 state is proposed. PPP-SCF-MO-CI method has been used to calculate charge densities on the heteroatoms. Key words: spectra, proton transfer.

scholarly journals A sensitive fluorescent sensor for highly sensitive detection of trace water in organic solvents based on substituted imidazole

2021 ◽  
Author(s):  
Huiqian Li ◽  
Weijian Xue ◽  
Jinping Wang ◽  
Jie Ma ◽  
Bing Zhao ◽  
...  
Keyword(s):  
Fluorescence Spectra ◽  
Fluorescent Sensor ◽  
Important Change ◽  
Red Shift ◽  
Imidazole Derivative ◽  
Absorption And Fluorescence Spectra ◽  
Highly Sensitive ◽  
Initial Discovery ◽  
Highly Sensitive Detection ◽  
Trace Water

Abstract A novel substituted imidazole derivative 1a with carboxyl and quinoline structure has been designed and synthesized. And our initial discovery is that this compound can effectively detect trace amounts of water in ethanol. And the metal in solution couldn’t affect the absorption and fluorescence Spectra of 1a. With the addition of water, the energy band appears a red-shift from 330nm to 355nm in the absorption spectra. And the emission spectrum undergoes an important change in its fluorescent effect in the presence of water. Furthermore, absorption peak of 1a displays a red-shift with increasing pH from 2.31 to 10.72. All available data (absorption and emission) strongly support the possible mechanism. Due to the pronounced fluorescence changing property, the substituted imidazole derivative 1a could be utilized as fluorescent probes for quantifying trace amount of water in ethanol. Graphic abstract

Proton-Induced Multiple Changes of the Absorption and Fluorescence Spectra of Amino-Aza-Oligo(Phenylenevinylene)s

2008 ◽  
Vol 55 ◽  
pp. 36-41 ◽  
Author(s):  
Volker Schmitt ◽  
Stefan Glang ◽  
Jasmin Preis ◽  
Heiner Detert
Keyword(s):  
Fluorescence Spectra ◽  
Fluorescent Dyes ◽  
Aldol Condensation ◽  
Emission Spectra ◽  
Solvent Polarity ◽  
High Sensitivity ◽  
Optical Spectra ◽  
Absorption And Fluorescence Spectra ◽  
Absorption And Emission ◽  
Absorption And Emission Spectra

Fluorescent dyes with a high sensitivity of their optical spectra towards changes of the environment were prepared via aldol condensation or Horner olefinations. The main chromophore is a quadrupolar N-substituted 1,4-distyrylbenzene which allows protonation and complexation at various positions resulting in a series of different and significant changes of the optical spectra. The sensitivity of the absorption and emission spectra on solvent polarity, acid, and cations is reported.

scholarly journals Highly sensitive detection of Cr(VI), Pb(II) and Cd(II) ions by a new fluorescent sensor based on 4-amino-3-hydroxynaphthalene sulfonic acid-doped polypyrrole

2020 ◽  
Vol 39 (2) ◽  
pp. 139
Author(s):  
Mohamed Lamine Sall ◽  
Abdou Karim Diaw ◽  
Diariatou Gningue-Sall ◽  
Mehmet Ali Oturan ◽  
Jean-Jacques Aaron
Keyword(s):  
Fluorescence Quenching ◽  
Sulfonic Acid ◽  
Fluorescence Spectra ◽  
Fluorescent Sensor ◽  
High Sensitivity ◽  
Metallic Ions ◽  
Excitation Peak ◽  
Main Band ◽  
Main Emission Peak ◽  
Highly Sensitive Detection

A new electrosynthesized, fluorescent 4-amino-3-hydroxynaphthalene-1-sulfonic acid-doped polypyrrole (AHNSA-PPy) was used for the detection of Cr(VI), Pb(II) and Cd(II) heavy metallic ions. The optical properties of AHNSA-PPy were studied by UV-VIS absorption and fluorescence spectrometry in diluted DMSO solutions. UV-VIS spectrum showed a main band at 260 nm, a moderate band at 240 nm, and shoulders at 285, 295, 320 and 360 nm, whereas the fluorescence spectrum presented an excitation peak at 330 nm and a main emission peak at 390 nm with a shoulder at 295 nm. The effects of heavy metallic ions, including Cr(VI), Pb(II), and Cd(II), on the AHNSA-PPy UV-VIS absorption and fluorescence spectra were investigated. AHNSA-PPy fluorescence spectra were strongly quenched upon increasing the Cr(VI), Pb(II) and Cd(II) concentrations. Linear Stern-Volmer relationships were established, and polynomial equations for Pb(II) and Cd(II) were obeyed, indicating the existence of a AHNSA-PPy dynamic fluorescence quenching mechanism for Cr(VI) and a combination of dynamic and static fluorescence quenching for Pb(II) and Cd(II). The AHNSA-PPy sensor showed high sensitivity for fluorescence detection of the three heavy metallic ions, with very low limits of detection (3σ) of 1.4 nM for Cr(VI), 2.7 nM for Cd(II) and 2.6 nM for Pb(II). Therefore, this very sensitive quenching fluorimetric sensor is proposed for the detection of trace, toxic heavy metallic ions in the environment.

scholarly journals The Influence of Shadow Effects on the Spectral Characteristics of Glacial Meltwater

2020 ◽  
Vol 13 (1) ◽  
pp. 36
Author(s):  
Kornelia Anna Wójcik-Długoborska ◽  
Robert Józef Bialik
Keyword(s):  
Spectral Properties ◽  
Satellite Images ◽  
Near Infrared ◽  
Spectral Band ◽  
Spectral Characteristics ◽  
High Sensitivity ◽  
Surface Model ◽  
Landsat 8 ◽  
Pixel Resolution ◽  
Ice Phenomena

The phenomenon of shadows due to glaciers is investigated in Antarctica. The observed shadow effect disrupts analyses conducted by remote sensing and is a challenge in the assessment of sediment meltwater plumes in polar marine environments. A DJI Inspire 2 drone equipped with a Zenmuse x5s camera was used to generate a digital surface model (DSM) of 6 King George Island glaciers: Ecology, Dera, Zalewski, Ladies, Krak, and Vieville. On this basis, shaded areas of coves near glaciers were traced. For the first time, spectral characteristics of shaded meltwater were observed with the simultaneous use of a Sequoia+ spectral camera mounted on a Parrot Bluegrass drone and in Landsat 8 satellite images. In total, 44 drone flights were made, and 399 satellite images were analyzed. Among them, four drone spectral images and four satellite images were selected, meeting the condition of a visible shadow. For homogeneous waters (deep, low turbidity, without ice phenomena), the spectral properties tend to change during the approach to an obstacle casting a shadow especially during low shortwave downward radiation. In this case, in the shade, the amount of radiation reflected in the green spectral band decreases by 50% far from the obstacle and by 43% near the obstacle, while in near infrared (NIR), it decreases by 42% and 21%, respectively. With highly turbid, shallow water and ice phenomena, this tendency does not occur. It was found that the green spectral band had the highest contrast in the amount of reflected radiation between nonshaded and shaded areas, but due to its high sensitivity, the analysis could have been overestimated. The spectral properties of shaded meltwater differ depending on the distance from the glacier front, which is related to the saturation of the water with sediment particles. We discovered that the pixel aggregation of uniform areas caused the loss of detailed information, while pixel aggregation of nonuniform, shallow areas with ice phenomena caused changes and the loss of original information. During the aggregation of the original pixel resolution (15 cm) up to 30 m, the smallest error occurred in the area with a homogeneous water surface, while the greatest error (over 100%) was identified in the places where the water was strongly cloudy or there were ice phenomena.

Synthesis, Spectroscopic Properties of Bis-Boc-L-alanine Modified 1,8-Naphthyridine Ligand Induced by Cr3+

2014 ◽  
Vol 716-717 ◽  
pp. 163-166
Author(s):  
Gao Zhang Gou ◽  
Bo Zhou ◽  
Ling Shi ◽  
Na Wu ◽  
Xian Lan Chen ◽  
...  
Keyword(s):  
Heavy Metal ◽  
Amino Acid ◽  
Metal Ions ◽  
Fluorescent Probe ◽  
Heavy Metal Ions ◽  
Fluorescence Spectra ◽  
Spectroscopic Properties ◽  
Ion Source ◽  
Absorption And Fluorescence Spectra ◽  
Comprehensive Study

One Bis-Boc-L-alanine-1,8-naphthyridine ligand containing amino acid by amido bond named 2,7-Bis-Boc-L-alanine-1,8-naphthyridine (L1) was synthesized and characterized. And there absorption and fluorescence spectra in methanol is presented. Then, the comprehensive study of spectroscopic properties upon titration of L1 with heavy metal ions as ion source in CH3OH was investigated. It shows compound L1 can use as a fluorescent probe for heavy metal ions like Cr3+.

scholarly journals Study the Optical and Spectral Properties of the Acridine Dye As an Effective Medium in Dye Lasers

2018 ◽  
Vol 26 (10) ◽  
pp. 167-180
Author(s):  
Afrah M. AL Hussainey ◽  
Ruaa Kahtan Mahmoud ◽  
Talib M. Abbas ALShafie
Keyword(s):  
Refractive Index ◽  
Optical Properties ◽  
Absorption Coefficient ◽  
Emission Spectrum ◽  
Spectral Properties ◽  
Fluorescence Spectra ◽  
Spectral Characteristics ◽  
Dye Lasers ◽  
Intensity Increase ◽  
Absorption And Fluorescence Spectra

         In this study, the absorption and fluorescence spectra of the dissolved Acridine solution were studied in ethanol and different concentrations. The optical properties (absorption coefficient, linear refraction) and spectral characteristics (Fluorescence time and quantitative fluoridation efficiency) were calculated. It is observed that increasing the concentration increases the absorbance values and decreases the permeability values, thus increasing the values of the absorption coefficient and the refractive index. Also, the values of the fluorine intensity increase. The peak of the emission spectrum is transferred to the longer wavelengths.                                                                                                                    

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