A novel ratiometric and reversible fluorescent probe based on naphthalimide for the detection of Al3+ and pH with excellent selectivity

2020 ◽  
Vol 44 (8) ◽  
pp. 3261-3267 ◽  
Author(s):  
Zhuo Li ◽  
Weihong Chen ◽  
Liuyan Dong ◽  
Yan Song ◽  
Ronghang Li ◽  
...  

A novel ratiometric and reversible fluorescence probe was designed and synthesized. The fluorescent probe recognizes Al3+ to cause a blue shift in the fluorescence emission spectrum. Fluorescence probe can be used as a sensor to detect Al3+ in living cells and Zebra fishes. The probe can detect the pH value when the alkalinity range was 8–10.

2001 ◽  
Vol 359 (3) ◽  
pp. 651-659 ◽  
Author(s):  
Inés PLASENCIA ◽  
Antonio CRUZ ◽  
Cristina CASALS ◽  
Jesús PÉREZ-GIL

A dansylated form of porcine surfactant-associated protein C (Dns-SP-C), bearing a single dansyl group at its N-terminal end, has been used to characterize the lipid–protein and protein–protein interactions of SP-C reconstituted in phospholipid bilayers, using fluorescence spectroscopy. The fluorescence emission spectrum of Dns-SP-C in phospholipid bilayers is similar to the spectrum of dansyl-phosphatidylethanolamine, and indicates that the N-terminal end of the protein is located at the surface of the membranes and is exposed to the aqueous environment. In membranes containing phosphatidylglycerol (PG), the fluorescence of Dns-SP-C shows a 3-fold increase with respect to the fluorescence of phosphatidylcholine (PC), suggesting that electrostatic lipid–protein interactions induce important effects on the structure and disposition of the N-terminal segment of the protein in these membranes. This effect saturates above 20% PG molar content in the bilayers. The parameters for the interaction of Dns-SP-C with PC or PG have been estimated from the changes induced in the fluorescence emission spectrum of the protein. The protein had similar Kd values for its interaction with the different phospholipids tested, of the order of a few micromolar. Cooling of Dns-SP-C-containing dipalmitoyl PC bilayers to temperatures below the phase transition of the phospholipid produced a progressive blue-shift of the fluorescence emission of the protein. This effect is interpreted as a consequence of the transfer of the N-terminal segment of the protein into less polar environments that originate during protein lateral segregation. This suggests that conformation and interactions of the N-terminal segment of SP-C could be important in regulating the lateral distribution of the protein in surfactant bilayers and monolayers. Potential SP-B–SP-C interactions have been explored by analysing fluorescence resonance energy transfer (RET) from the single tryptophan in porcine SP-B to dansyl in Dns-SP-C. RET has been detected in samples where native SP-B and Dns-SP-C were concurrently reconstituted in PC or PG bilayers. However, the analysis of the dependence of RET on the protein density excluded specific SP-B–Dns-SP-C associations.


2012 ◽  
Vol 554-556 ◽  
pp. 254-257
Author(s):  
Zhe Zhou ◽  
Zong Yi Qin ◽  
Xin Liu ◽  
Guang Zhao Zhai ◽  
Long Chen

A novel polyacrylonitrile (PAN)-based fluorescence probe was prepared by chemically combining the aminoanthraquinone as a fluorescent group with the PAN chains. It is found that the -C≡N group in PAN chains can affect the photolysis of anthraquinone groups. The results show that the conformational state and aggregation behavior of PAN can be monitored by observing the intensity variation in fluorescence emission spectrum for PAN-AAQN solutions.


2015 ◽  
Vol 51 (32) ◽  
pp. 6925-6927 ◽  
Author(s):  
Fanpeng Kong ◽  
Xiaoyue Meng ◽  
Ranran Chu ◽  
Kehua Xu ◽  
Bo Tang

Based on a unique elimination reaction prompted by the iodide, a turn-on fluorescent probe (HCy-OMe-Br) without containing heavy metal has been developed for the first time. The probe can monitor iodide with excellent selectivity and sensitivity and was successfully applied to visualize iodide in living cells.


2019 ◽  
Vol 2019 ◽  
pp. 1-9 ◽  
Author(s):  
Li Jin ◽  
Ying Wang ◽  
Fengkai Yan ◽  
Jianpo Zhang ◽  
Fangli Zhong

Nitrogen-doped graphene quantum dots had been successfully synthesized and characterized by using transmission electron microscope, X-ray photoelectron spectroscopy, absorbance spectrum, fluorescence emission spectrum, and fluorescence decay curve. TEM results indicated that the diameters of the as-prepared nitrogen-doped graphene quantum dots were in the range of 2 - 5 nm and the lattice space is about 0.276 nm; Raman spectrum result indicated that there were two characteristic peaks, generally named D (~1408 cm−1) and G (~1640 cm−1) bands; both TEM and Raman spectrum results indicated that the as-synthesized product was graphene quantum dots. Deconvoluted high resolution XPS spectra for C1s, O1s, and N1s results indicated that there are -NH-, -COOH, and -OH groups on the surface of nitrogen-doped graphene quantum dot. Fluorescence emission spectrum indicated that the maximum fluorescence emission spectrum of nitrogen-doped graphene quantum dots was blue shift about 30.1 nm and the average fluorescence decay time of nitrogen-doped graphene quantum dots increased about 2 ns, compared with graphene quantum dots without doping of nitrogen. Then, the as-prepared nitrogen-doped graphene quantum dots were used to quantitatively analyze brilliant blue based on the fluorescent quenching of graphene quantum dots, and the effect of pH and reaction time on this fluorescent quenching system was also obtained. Under selected condition, the linear regression equations were F0/F=0.0087 (brilliant blue) + 0.9553 and F0/F=0.01205 (brilliant blue) + 0.6695, and low detection limit was 3.776 μmol/L (3.776 nmol/mL). Once more diluted N-GQDs (0.05 mg/mL) were used, the low detection limit could reach 94.87 nmol/L. Then, temperature-dependent experiment, absorbance spectra, and dynamic fluorescence quenching rate constant were used to study the quenching mechanism; all results indicated that this quenching process was a static quenching process based on the formation of complex between nitrogen-doped graphene quantum dots and brilliant blue through hydrogen bond. Particularly, this method was used to quantitatively analyze the wine sample, of which results have a high consistence with the results of the spectrophotometric method; demonstrating this fluorescence quenching method could be used in practical sample application.


2019 ◽  
Vol 43 (23) ◽  
pp. 9090-9105 ◽  
Author(s):  
Kannan Ramamurthy ◽  
E. J. Padma Malar ◽  
Chellappan Selvaraju

Fluorescence emission spectrum of ketocoumarin dimers in an alcohol:water binary mixture and the solid state.


2019 ◽  
Vol 43 (21) ◽  
pp. 8132-8145 ◽  
Author(s):  
Parisa Mokaberi ◽  
Vida Reyhani ◽  
Zeinab Amiri-Tehranizadeh ◽  
Mohammad Reza Saberi ◽  
Sima Beigoli ◽  
...  

Demonstrates the overlap that had been induced between the fluorescence emission spectrum of Hb and the absorption spectrum of drugs, which has proved that there is a high probability to the occurrence of energy transfer from Hb and LMF in the absence and presence of NRF.


1994 ◽  
Vol 301 (3) ◽  
pp. 885-891 ◽  
Author(s):  
M Vas ◽  
A Merli ◽  
G L Rossi

The analogue of ATP, 2′(3′)-O-(2,4,6-trinitrophenyl)adenosine 5′-triphosphate (TNP-ATP), binds tightly to pig muscle 3-phosphoglycerate kinase. A dissociation constant Kd of 0.0095 +/- 0.0015 mM was determined by fluorimetric titration on the basis of 1:1 stoichiometry. TNP-ATP is a strong competitive inhibitor towards MgATP and MgADP with a Ki of 0.008 +/- 0.001 mM for both substrates. It is also a mixed-type inhibitor towards 3-phosphoglycerate with similar inhibition constants. Binding of TNP-ATP to 3-phosphoglycerate kinase is accompanied by a tenfold intensity increase and a blue shift of about 20 nm in its fluorescence emission spectrum and a shift of the pK of its trinitrophenyl group towards a more acidic pH. These findings suggest that the negatively charged trinitrophenyl group of TNP-ATP significantly contributes to the binding of the analogue. By stepwise replacement of the fluorescent TNP-ATP, the dissociation constants (Kd) for ADP and MgADP binding were determined and found to be 0.78 +/- 0.08 and 0.048 +/- 0.006 mM respectively, which are consistent with the values previously determined by equilibrium dialysis [Molnár and Vas (1993) Biochem J. 293, 595-599]. In similar competitive-titration experiments, ATP and MgATP did not completely substitute for TNP-ATP. For the fraction of the analogue that could be substituted, the dissociation constants for MgATP and ATP were estimated to be 0.27 +/- 0.09 and 0.33 +/- 0.15 mM respectively, close to the values determined by equilibrium dialysis. Using the same method, a significant weakening of binding of both (Mg)ADP and (Mg)ATP could be detected in the presence of 3-phosphoglycerate: their respective Kd values became 0.34 +/- 0.04 and 0.51 +/- 0.22 mM. The reciprocal effect, i.e. weakening of 3-phosphoglycerate binding in the presence of the nucleotide substrates, has been observed previously [Vas and Batke (1984) Eur. J. Biochem. 139, 115-123]. Similarly, a much weaker binding of (Mg)ATP could be observed in the presence of 1,3-bisphosphoglycerate (Kd = 2.30 +/- 0.68 mM). The possible reason for the mutual weakening of substrate binding is discussed in the light of the available structural data.


2016 ◽  
Vol 4 (41) ◽  
pp. 6662-6669 ◽  
Author(s):  
Xuan Zhang ◽  
Jing-Yun Liu ◽  
Wei-Wei Ma ◽  
Meng-Lu Yang

The fluorescence emission of benzothiazole derivatives (1–3) was efficiently tuned from green to red by elongation of π-conjugation, and a novel NIR fluorescent probe for biothiols was constructed which allows for imaging applications in living cells.


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