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Biothiol detection by “ON-OFF-ON” fluorescence probe based on anthracene derivative
摘要： Two thiols fluorescent probes of copper complex based on anthracene derivative was designed. Two compounds (1 and 2) were obtained by the reaction of 9-furaldehyde with benzenesulfonamide and p-nitrobenzenesulfonamide. Then, these compounds were combined with copper ion and two copper complexes (compound 1-Cu2+ and compound 2-Cu2+) formed. Due to the paramagnetic effect of copper caused fluorescence quenching, two compounds showed strong fluorescence while compound-Cu2+ almost had no fluorescence. With the additions of cysteine (Cys) and glutathione (GSH), the fluorescence intensities recovered again. While the additions of other amino acids almost did not induce any change. UV-Vis, fluorescence spectra and Circular Dichroism suggested that two copper complexes showed better selectivity and sensitivity to small molecule biothiols among amino acids tested. In addition, cytotoxicity experiments showed that two fluorescence probes have potential application value for biological thiols detection in live cells.
关键词： Cytotoxicity experiment,Fluorescent probe,Biological thiols,Circular dichroism,9-furaldehyde
更新于2025-09-09 09:28:46
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Colorimetric and NIR fluorescence probe with multiple binding sites for distinguishing detection of Cys/Hcy and GSH in vivo
摘要： Although some progress has been made in distinguishing detection of biothiols, NIR biothiol fluorescent probes for simultaneous distinguishing detection of Cys, Hcy and GSH in vivo have not been reported. The design of these probes involves the introduction of NIR fluorophores and multiple binding sites, so the integrated design of probes remains a challenge. Although Cys, Hcy and GSH have the common functional group: a sulfydryl group and an amino group, due to their differences in spatial structure, they may react with multiple binding sites probes to produce different reaction products in different bonding mechanisms, resulting in the different colors and fluorescent signals changes of the system. Therefore, multiple binding sites fluorescent probes can realize their discrimination detection. For NIR fluorescent probe, it is easier to realize in vivo imaging to promote the research of biothiols in clinical diagnosis. In our work, not only multiple binding sites were constructed in the compound, but also NIR fluorophores were introduced. This enables the probe to not only efficiently distinguish detection of Cys/Hcy and GSH but also achieve fluorescence imaging in vivo. We believe this result is a milestone in the discrimination detection of biothiols.
关键词： Cys/Hcy,in vivo,NIR fluorescence probe,GSH,Colorimetric,multiple binding sites
更新于2025-09-09 09:28:46
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Ultrafast excited-state dynamics in chlorosomes isolated from the photosynthetic filamentous green bacterium <i>Chloroflexus aurantiacus</i>
摘要： Bacteriochlorophyll (BChl) c pigments in the aggregated state are responsible for efficient light harvesting in chlorosomes of the filamentous anoxygenic photosynthetic bacterium, Chloroflexus (Cfx.) aurantiacus. Absorption of light creates excited states in the BChl c aggregates. After sub-picosecond intrachlorosomal energy transfer, redistribution and relaxation, the excitation is transferred to the BChl a complexes and further to reaction centres on the picosecond time scale. In this work, the femtosecond excited state dynamics within BChl c oligomers of isolated Cfx. aurantiacus chlorosomes was studied by double difference pump-probe spectroscopy at room temperature. Difference (Alight ? Adark) spectra corresponding to excitation at 725 nm (blue side of the BChl c absorption band) were compared with those corresponding to excitation at 750 nm (red side of the BChl c absorption band). A very fast (time constant 70 ± 10 fs) rise kinetic component was found in the stimulated emission upon excitation at 725 nm. This component was absent at 750-nm excitation. These data were explained by the dynamical red shift of the stimulated emission due to excited state relaxation. The nature and mechanisms of the ultrafast excited state dynamics in chlorosomal BChl c aggregates are discussed.
关键词： excited-state dynamics,Chloroflexus aurantiacus,Bacteriochlorophyll,chlorosomes,pump-probe spectroscopy
更新于2025-09-09 09:28:46
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A novel colorimetric and ratiometric fluorescent probe for selective detection of bisulfite in real samples and living cells
摘要： An abnormal level of bisulfite can induce toxicological effects associated with lung cancer, cardiovascular and neurological disorders. Therefore, it is of significance to develop an effective fluorescent probe to detect bisulfite in living cells. Herein, a novel fluorescent probe QPCT, based on a 1,4-addition mechanism, was constructed for the colorimetric and ratiometric detection of bisulfite. QPCT displayed high selectivity and anti-interference ability to bisulfite over other anions and biothiols. The probe renders a sensitive ratiometric response to bisulfite with a remarkable fluorescence blue shift from 590 to 537 nm and the fluorescence ratio was linear with bisulfite concentration over the range of 0-120 μM. More importantly, QPCT has been successfully applied to detect bisulfite in sugars and living A549 cells, which indicated that QPCT had a great capability for monitoring bisulfite in complex systems.
关键词： Real samples,Fluorescent probe,Live-cell imaging,Bisulfite,Colorimetric and ratiometric
更新于2025-09-09 09:28:46
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A novel near-infrared “turn-on” fluorescent probe for selective detection of Fe3+ and its application in vitro imaging
摘要： A novel near-infrared fluorescent probe RHCC was devised and synthesized. It exhibits high specificity to Fe3+ compared to other metals in aqueous solutions. The detection limit of RHCC was 1.2 × 10-7 M and the complexation stability constant was 5.807 × 104 M-1. The binding ratio of RHCC and Fe3+ was 1:1 which was measured through MS, FTIR and Job’s plot. The energy gap between HOMO and LUMO of RHCC was 3.22 eV, while RHCC-Fe3+ complex was 0.95 eV. This result means the binding of probe RHCC and Fe3+ lowers the RHCC-Fe3+ complex’s energy gap and makes it more stable. What’s more, in living cells and zebrafishes studies, probe RHCC was no significant cytotoxic effect, indicating it could monitor Fe3+ in biological system.
关键词： near-infrared probe,vitro imaging,“turn-on”,high specificity
更新于2025-09-09 09:28:46
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The carbon dots as colorimetric and fluorescent dual-readout probe for 2-nitrophenol and 4-nitrophenol detection
摘要： Herein, the fluorescent carbon dots (CDs) has been synthesized by hydrothermal method by using ethylene diamine tetraacetic acid (EDTA) as a raw materials. The prepared CDs exhibited bright blue fluorscence excited by 340 nm with the quantum yield as high as 52%. The CDs possess special fluorescence responses to 2-nitrophenol (2-NP) and 4-nitrophenol (4-NP), and the slump of fluorescence was demonstrated by CDs solution in the case of 2-nitrophenol and 4-nitrophenol existence. The detection limit of 2-NP and 4-NP was calculated at 77 nM and 60 nM, respectively. Meanwhile, the color response to 2-NP and 4-NP can be observed from achromatic solution to yellow by naked eye. All in all, the obtained CDs can be applied as fluorescence and colorimetric probe in environmental protection.
关键词： Carbon dots,Dual-readout probe,2-nitrophenol,4-nitrophenol,Detection
更新于2025-09-09 09:28:46
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A smart approach toward rhodamine spiro-ring derivatives sensing platform for lysosome-targetable imaging applications
摘要： As acidic organelles (pH 4.0-5.5) in living cells, lysosomes play key roles in numerous cellular biological processes, and associate with diverse diseases. Small molecular probes based fluorescence imaging techniques capable of providing information on target analytes in lysosomes are highly appreciated. Herein, for the first time we propose a new strategy of constructing pH-independent rhodamine based spiro-ring platform for lysosomal imaging applications. As a proof of concept, by incorporating lysosome specific moiety morpholine, a thio-lactone rhodamine analogue HN4MS for HOCl with high sensitivity, high selectivity and fast response at lysosomal pH value was developed. Moreover, possessing ability of imaging in lysosome organelles, the new probe was successfully applied to visualize exogenous and endogenous HOCl in living cells and tissues, which verified the present avenue for expansion of organelle targetable imaging tools.
关键词： Spiro-ring,Imaging,Fluorescent probe,Lysosome-targetable,HOCl
更新于2025-09-09 09:28:46
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Recent Developments and Applications of Photoconjugation Chemistry
摘要： Understanding of biological systems has always been the general interest in chemical biology, and chemical modifications of biomolecules are often required to elucidate their functions and properties. There has thus been a rapid development of covalent chemistries for the modification of macromolecules. Among these strategies, photochemistry provides the advantage of using biocompatible light as an energy source to trigger bioconjugation reactions; this circumvents the use of toxic reagents (e.g. metal catalysts and chelating ligands). Light-induced chemistry can achieve precise spatial and temporal conjugation of biomolecules in their native environment.
关键词： Chemical biology,Photoconjugation,Bioorthogonal ligation,Small molecule probe
更新于2025-09-09 09:28:46
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A curcumin-based NIR fluorescence probe for detection of amyloid-beta (Aβ) plaques in Alzheimer's disease
摘要： Amyloid-beta (Aβ) peptide as one of the main components of senile plaques is closely related to the onset and progression of incurable Alzheimer's disease (AD). In recent years, it is reported that curcumin derivatives have been used as the near-infrared (NIR) fluorescence imaging probes of Aβ plaques for the early diagnosis of AD. To further develop a curcumin-based NIR fluorescent probe for Aβ plaques, in this work, we have synthesized three novel curcumin-based NIR Dyes. Among them, the curcumin derivative Dye 2 showed a significant enhancement in its fluorescence intensity (λem, 635 nm; 19.5-fold increase in quantum yield, Φ = 0.36; Kd, 1.13 μM) after binding to Aβ plaques. Additionally, in vitro and in vivo fluorescence imaging of Aβ plaques strained with Dye 2 confirmed that the compound was a potential probe to detect Aβ plaques in AD. This work opens a perspective to rationally design novel curcumin-based NIR compound for Aβ detection.
关键词： Alzheimer’s Disease,Fluorescence imaging,Amyloid-beta deposits,NIR fluorescence probe,Curcumin,Amyloid-beta plaques
更新于2025-09-09 09:28:46
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A 1,8 Naphthalimide anchor Rhodamine B Based FRET Probe for Ratiometric Detection of Cr3+ion in Living Cells
摘要： A 2-(1,3-dioxo-1H-benzo[de]isoquinolin-2(3H)-yl)acetaldehydeanchored rhodamine B based probe, RDNAP detects Cr3+ ion by fluorescence resonance energy transfer (FRET) process in aqueous buffered acetonitrile media (7:3, v/v). Conversely, conjugation of 2-(1,3-dioxo-6-(piperidin-1-yl)-1H-benzo[de]isoquinolin-2(3H)-yl)acetaldehyde with rhodamine B provides another probe, RDNAP-PY that undergoes Cr3+assisted ratiometric fluorescence and colorimetric change in the same media. RDNAP-PY provides higher FRET efficiency and detects as low as 1.81×10?6 M Cr3+with an association constant, 15.9 × 104 M-1. Other common ions do not interfere. RDNAP-PY efficiently images intracellular Cr3+ in live Hep3B, MCF-7, HeLa, SiHa and HEK 293T cells under fluorescence microscope in a ratiometric and time dependent manner. 1H NMR titration and DFT studies strongly support experimental findings.
关键词： 1,8 Naphthalimide,Live cell imaging,Ratiometric probe,fluorescence resonance energy transfer,DFT calculation
更新于2025-09-09 09:28:46