A turn-on fluorescent probe for Au3+ based on rodamine derivative and its bioimaging application

A new fluorescent probe RY was synthesized for the detection of Au³⁺ ions based on a rhodamine B derivative. The fluorescent probe showed good selectivity and sensitivity to Au³⁺ ions. Obvious color and fluorescence changes could be observed with the naked eye while the fluorescent probe reacted with the Au³⁺ ions. The detection limit of the probe was determined to be 36 ppb by the fluorescence titration; the excellent linear relationship suggests that the probe is potentially useful for quantitative detection of Au³⁺ in vitro. We also demonstrated its bioimaging application in both living cells and mice; this was the first time that a fluorescent probe was successfully applied to imaging Au³⁺ in living animals.     

A novel ratiometric fluorescent probe based on coumarin derivative for the recognition of Al(III) and its application on test strips

A novel ratiometric probe (L) which was composed of chromone and coumarin moieties has been designed and synthesized for sensing Al³⁺ in EtOH in view of the internal charge transfer (ICT) mechanism. The free probe L exhibited a strong fluorescence emission at 477 nm, and the fluorescence emission here almost disappeared after adding Al³⁺ (10 equiv.) while a new peak appeared at 524 nm. This may be due to the enhancement of intramolecular electron transfer efficiency from donor to acceptor. In addition, this probe L could be form a 1:1 complex with Al³⁺, which could be explained by the ESI-MS spectra, and L had a low detection limit for Al³⁺ with a binding constant of 1.32 × 10⁴ M⁻¹. More importantly, L could be applied to a solid probe for rapid detection of Al³⁺ with a significant color change.     

A Rhodamine-based fluorescent sensor for chromium ions and its application in bioimaging

A rhodamine-based sensor (1) has been developed for the detection of chromium ions. Cr³⁺-induced opening of the rhodamine spirocycle in sensor (1) led to the distinct colorimetric and fluorescence responses. Among all the tested ions, only Cr³⁺ generated a significant fluorescence enhancement of up to 13-fold, which indicated the high selectivity of 1. Sensor (1) was successfully applied in the in vivo fluorescence imaging of Cr³⁺ in C. elegans. The results provided solid evidences for the future estimation of Cr³⁺ in environmental applications and tobacco samples.     

Design and preparation of a novel fluorescent naphthalimide derivative supramolecular self-assembly system and its bioimaging application

ABSTRACT

A novel fluorescent naphthalimide derivative gelator (N-18) was designed and characterised which could form a stable gel in 1,4-dioxane/H₂O (2/1, v/v), methyl sulfoxide (DMSO), ethanol/H₂O (4/1, v/v), acetone/H₂O (2/1, v/v) and methanol. The self-assembly process of molecule N-18 in the five solvents was carefully investigated by the field emission scanning electron microscope, UV-vis absorption spectra, fluorescence emission spectra, fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD) and water contact angle experiments. Different structures from microbelts to helical nanofibers were formed in the self-assembly process. Hydrogen bonding and π–π stacking interaction were the mainly driving forces for the formation of gel. At the same time, the hydrophobic surface with the contact angles of 133°–142° was observed on the xerogel films N-18 from the above five solvents. Interestingly, molecule N-18 could be applied in bioimaging in a living cell.     

Salicylimine-based fluorescent chemosensor for aluminum ions and application to bioimaging

In this study, an assay to quantify the presence of aluminum ions using a salicylimine-based receptor was developed utilizing turn-on fluorescence enhancement. Upon treatment with aluminum ions, the fluorescence of the sensor was enhanced at 510 nm due to formation of a 1:1 complex between the chemosensor and the aluminum ions at room temperature. As the concentration of Al(3+) was increased, the fluorescence gradually increased. Other metal ions, such as Na(+), Ag(+), K(+), Ca(2+), Mg(2+), Hg(2+), Mn(2+), Co(2+), Ni(2+), Cu(2+), Zn(2+), Cd(2+), Pb(2+), Cr(3+), Fe(3+), and In(3+), had no such significant effect on the fluorescence. In addition, we show that the probe could be used to map intracellular Al(3+) distribution in live cells by confocal microscopy.     

A monostyryl-boradiazaindacene (BODIPY) derivative as colorimetric and fluorescent probe for cyanide ions

We developed a novel boradiazaindacene derivative to detect cyanide ions in solution at micromolar concentrations. This structurally simple chemosensor displays a large decrease in emission intensity and a reversible color change from red to blue on contact with cyanide ions. Highly fluorescent polymeric films can be obtained by doping with the chemosensor. Such polymeric materials can be used for the sensing of the cyanide ions in polymer matrices.     

An anthracene based fluorescent probe for the selective and sensitive detection of Chromium (III) ions in an aqueous medium and its practical application

An anthracene based fluorescent probe, integrated with thiophene moiety, exhibited selective and sensitive detection of chromium (III) ions over other metal ions. Its synthesis was achieved by simple mixing of two commercially available compounds, 2-aminoanthracene, and 2-thiophenecarboxaldehyde, in onestep without the needed complex purification process. The probe molecule ( ANT-Th ) offered exceptional features such as “turn-on” fluorescence response, low detection limit (0.4 μM), and fast response time (<1 min) via C=N bond hydrolysis. Also, a simple test paper system was developed for the rapid detection of chromium (III) ions with the naked eye.     

Turn-on fluorescent probe for Zn2+ ions based on thiazolidine derivative

In this study, simple on–off fluorescent/UV–visible (UV–Vis) probes were easily prepared using 2-(2-hydroxyphenyl)thiazolidine-4-carboxylic acid ( Sen-1 ) and/or 2-(2-hydroxy-5-nitrophenyl)thiazolidine-4-carboxylic acid ( Sen-2 ) for fast detection of Zn²⁺ ions. Their sensing properties towards common metal ions were investigated using UV–Vis and fluorescence spectroscopies. Sen-1 and Sen-2 displayed a significant change with the addition of Zn²⁺ ions in the UV–Vis spectra. The addition of Zn²⁺ ions induced a 104 nm bathochromic shift for Sen-1 . The binding ratio towards Zn²⁺ metal ions was determined to be 1:1 by using Job plot analysis and fluorescence spectroscopy. The association constant and free energy (ΔG) of Sen-1 and Sen-2 towards Zn²⁺ ions were calculated by the Benesi–Hildebrand equation. The limit of detection of Sen-1 towards Zn²⁺ ions is 3.73 × 10⁻⁸ M, which is about 1/100 of the value recommended by the World Health Organization for drinking water. Sen-1 was successfully applied to detect Zn²⁺ ions in water samples and the fluorescence test strip was prepared for visual detection of Zn²⁺ ions. Finally, the quantum chemical parameters of Sen-1 and Sen-2 , such as highest occupied molecular orbital, lowest unoccupied molecular orbital, and chemical hardness, were investigated by the Becke, three-parameter, Lee–Yang–Parr, Hartree–Fock, and M062x methods.     

A naked-eye rhodamine-based fluorescent probe for Fe(III) and its application in living cells

A naked-eye turn-on fluorescent Fe³⁺ probe (RQ6) was developed by linking a new conjugated quinoline fluorescent group to the rhodamine platform. The probe can detect Fe³⁺ with high selectivity over other metal ions. Bioimaging studies indicated that RQ6 was cell permeable and suitable for detecting Fe³⁺ in the living cells by confocal microscopy.     

A distyryl BODIPY derivative as a fluorescent probe for selective detection of chromium(III)

A new boradiazaindacene (BODIPY) derivative (1a) bearing simple NO bidentate ligands has been synthesized. The 1a molecule behaves as a fluorescent probe for Cr³⁺ and shows strong red fluorescence upon coordination with Cr³⁺, while showing almost no fluorescence for other metal cations.     

Fluorescent probe for copper(II) ion based on a rhodamine spirolactame derivative, and its application to fluorescent imaging in living cells

A fluorescent probe for Cu(II) ion is presented. It is based on the rhodamine fluorophore and exhibits high selectivity and sensitivity for Cu(II) ion in aqueous methanol (2:8, v/v) at pH 7.0. The response is based on a ring opening reaction and formation of a strongly fluorescent 1:1 complex. The response is reversible and linear in the range between 50?nM and 900?nM, with a detection limit of 7.0?nM. The probe was successfully applied to fluorescent imaging of Cu(II) ions in HeLa cells.

一种检测肼的纳米粒子探针及其生物成像应用

肼是一种广泛使用的化工原料,但它也是一种有毒化学品,对人类健康和环境安全有着严重威胁.因此,开发一种方便、快速检测肼的方法具有重要的意义.本文制备了一种芘甲醛纳米粒子探针,其能和肼快速反应,从而使探针的荧光信号发生变化,实现对肼的荧光检测.该探针检测肼具有高选择性和灵敏度,并成功地应用于HeLa细胞和斑马鱼中肼的成像.     

A ratiometric fluorescent probe for iron(III) and its application for detection of iron(III) in human blood serum

A simple and versatile ratiometric fluorescent Fe³⁺ detecting system, probe 1, was rationally developed based on the Fe³⁺-mediated deprotection of acetal reaction. Notably, this reaction was firstly employed to design fluorescent Fe³⁺ probe. Upon treatment with Fe³⁺, probe 1 showed ratiometric response, with the fluorescence spectra displaying significant red shift (up to 132 nm) and the emission ratio value (I₅₂₂/I₃₉₀) exhibiting approximately 2362-fold enhancement. In addition, the probe is highly sensitive (with the detection limit of 0.12 μM) and highly selective to Fe³⁺ over other biologically relevant metal ions. The sensing reaction product of the probe with Fe³⁺ was confirmed by NMR spectra and mass spectrometry. TD-DFT calculation has demonstrated that the ratiometric response of probe 1 to Fe³⁺ is due to the regulation of intramolecular charge transfer (ICT) efficiency. Moreover, the practical utility in fluorescence detection of Fe³⁺ in human blood serum was also conducted, and probe 1 represents the first ratiometric fluorescent probe that can be used to monitor Fe³⁺ level in human blood serum. Finally, probe 1 was further employed in living cell imaging with pancreatic cancer cells, in which it displayed low cytotoxicity, satisfactory cell permeability, and selective ratiometric response to Fe³⁺.     

Fluorescence turn-on chemosensor for Hg~(2+) based on a rhodamine derivative and its application in bioimaging

A fluorescence turn-on chemosensor based on rhodamine B derivative (FD10) has been developed as a highly sensitive chemosensor for Hg2+. A prominent fluorescence enhancement was measured in the presence of Hg2+, which was in agreement with the changes in the absorption spectrum. Furthermore, by means of laser scanning fluorescence microscopy experiments, it was demonstrated that FD10 was cell-permeable and could be used as a fluorescent probe for monitoring Hg2+ in living cells.     

A novel lipid droplets-targeting fluorescent probe based on dicyanisophorone and carbazole for Cu2+ and its application

A novel fluorescent probe, LCH , based on dicyanisophorone and carbazole, was prepared for the visual detection of Cu²⁺. The probe LCH could recognize Cu²⁺ by fluorescence quenching in EtOH/H₂O (1/4, v/v) solution, which could be easily identified under the 365 nm UV lamp, and the detection limit was as low as 0.785 μM. The recognition mechanism of probe LCH with Cu²⁺ was determined by combining ¹H NMR titration, MS, and theoretical calculations. Practical application experiments showed that probe LCH could be used to detect Cu²⁺ in the test strip experiments. Cell imaging experiments showed that the probe LCH owned good cell permeability and could be applied to the imaging of Cu²⁺ in HepG2 cells. In addition, fluorescence colocalization experiments showed that LCH could target lipid droplets. These results indicate that the probe LCH will have a good application prospect in environmental detection and clinical medicine.     

Cu(2+)-selective fluorescent chemosensor based on coumarin and its application in bioimaging

A new fluorescent sensor L1 based on coumarin was synthesized. It shows high sensitivity and selectivity toward Cu(2+) in aqueous solution. The complexation mode and corresponding quenching mechanism were elucidated by ESI-MS and DFT calculations. In addition, biological imaging studies have demonstrated that L1 can detect Cu(2+) in living cells.     

A novel turn-on fluorescent probe for Hg2+ detection based on rhodamine B spirolactam derivative

ABSTRACT

In this work, a new turn-on fluorescent probe 1 for Hg²⁺ ions detection based on rhodamine B spirolactam was reported. Among tested metal ions, probe 1 shows high selectivity towards Hg²⁺ in the the mixture solution of methanol and 0.02 M HEPES buffer (V/V = 9:1, pH = 7.2). No absorption and emission band of probe 1 was observed in the range from 450 to 700 nm. While only addition of Hg²⁺ to probe 1 could lead to appearance of a new absorption band centered at 553 nm and a fluorescence emission band around 577 nm upon excitation at 520 nm. Moreover, it exhibits excellent linear relationship (R² = 0.9993) between fluorescence intensity at 577 nm and the concentration of Hg²⁺ from 1.6 to 32 μM. The sensing mechanism was proven to be spirolactam ring open induced by Hg²⁺ through ¹H NMR, MS, absorption and fluorescence spectra. In addition, probe 1 could detect Hg²⁺ in real water samples and on filter paper, which demonstrates its application in environment science.     

A novel fluorescent probe for zinc ion based on boron dipyrromethene (BODIPY) chromophore

ZnAB has the combined structure of N,N-bis(2-pyridylmethyl)ethylenediamine as a specific chelater for Zn(2+) and 1,3,5,7-tetramethyl-8-phenyl-boron dipyrromethene as a fluorophore. Complexation of ZnAB with Zn(2+) produces a remarkable enhancement of fluorescence intensity. ZnAB has the advantages of less sensitivity to solvent polarity and pH than fluorescein-based Zn(2+) probes. Furthermore, it is not influenced by other cations, such as Na(+), K(+), Ca(2+), and Mg(2+), which exist at high concentrations under physiological conditions, even at 2.5 mM. The results show that ZnAB is a Zn(2+) probe suitable for biological applications.     

Construction of a novel cell-trappable fluorescent probe for hydrogen sulfide (H2S) and its bio-imaging application

Analytical and Bioanalytical Chemistry - Fluorescence detection of H2S in living organisms is greatly advantageous because it is nondestructive and can be used for in situ analysis. We have...     

A selective turn-on fluorescent sensor for Fe and application to bioimaging

A novel compound FD1 was demonstrated as a turn-on fluorescent sensor for imaging of iron(III) ion in biological samples. Based on the spirolactam (nonfluorescence) to ring-open amide (fluorescence) equilibrium, FD1 exhibited high selectivity and sensitivity for Fe³⁺ over other metal ions. Moreover, fluorescent microscopy experiments further established that FD1 could be used for sensing Fe³⁺ within living cells.