- 标题
- 摘要
- 关键词
- 实验方案
- 产品
-
A novel coumarin-based fluorescence chemosensor for Al3+ and its application in cell imaging
摘要： As an efficient turn-on fluorescent chemosensor for Al3+, a new coumarin derivative (CND) has been designed and synthesized by the condensation of 8-formyl-7-hydroxycoumarin with niacin hydrazide. The spectroscopic studies revealed that the sensor CND exhibited a remarkable fluorescence enhancement towards Al3+ with high selectivity and sensitivity in EtOH-HEPES (95:5, v/v, pH = 7.40), which was attributed to the photoinduced electron transfer (PET) and -C=N isomerization mechanism. Fluorescence titration calculations data showed that the detection limit and the association constants of CND for Al3+ were found to be 2.51×10-7 M and 9.64×104 M-1, respectively. The results of experiments, including Job,s plot, 1H NMR titration and ESI-MS, revealed that the stoichiometric binding between CND and Al3+ was 1:1. The investigations of the pH dependency of CND for Al3+ detection, and the cell imaging suggested the sensor CND could be promisingly applied for the recognition of Al3+ in biological cells.
关键词： chemosensor,coumarin,live cells,Al3+
更新于2025-09-23 15:21:01
-
Visible-Light-Activated High-Density Materials for Controlled in Vivo Insulin Release
摘要： In this work, we describe the synthesis, characterization, and ultimate in vivo assessment of second-generation insulin photoactivated depot (PAD) materials. These are the first to use visible light to stimulate insulin release and have an in vivo performance that is 28-fold improved relative to first-generation materials. This improvement is due to two major factors linked to the utilized chemistry: (1) we have incorporated the coumarin photo-cleavable group, which increases the photorelease wavelength into the visible range, enhancing tissue penetration of the light; (2) photo-toggling of insulin solubility is produced by linking three insulin molecules to a central bridge via light cleaved groups, and not by bonding to a large polymer. The resulting trimer is, therefore, highly dense (87% insulin dry w/w) but retains the insolubility required of the approach. Only after irradiation with visible light is native, soluble insulin released from the dermal depot. This high density increases the amount and ease of insulin release, as the density of photolytic groups is 10?20-fold higher than in polymer-based first-generation materials. We have synthesized new azide-terminated coumarin linkers that we react with the amine groups of insulin. Using mass spectrometry methods, we identify the sites of reaction and purify individual isomers, which we demonstrate have in vitro photolysis rates that are within a factor of 2 of each other. We then reacted these terminal azide groups with a tridentate strained alkyne linker. We show that the resulting insulin trimer is highly insoluble, but can be milled into injectable particles that release insulin only in response to light from a 406 nm light source. Finally, we demonstrate that these materials have a significantly improved in vivo performance, releasing 28-fold more insulin on a per energy basis than first-generation materials.
关键词： photolysis,protein chemistry,insulin,coumarin,click chemistry
更新于2025-09-23 15:19:57
-
CO2 and photo-controlled reversible conversion of supramolecular assemblies based on water soluble pillar[5]arene and coumarin-containing guest
摘要： In this communication, a new supramolecualr amphiphile was successfully constructed based on water soluble pillar[5]arene and a unique guest which contain a CO2 responsive tertiary amine unit and a UV responsive coumarin group. When guest molecule 1 dispersed in water, it self-assembled into sheet-like structures. Upon bubbling CO2, 1 transformed into 1H due to the tertiary amine unit was protonated, accompany the nano-sheets transformed into vesicles. Further irradiation of 1H with 365 nm light for 3 h, the coumarin group reacted with each other to form bola-type amphiphie 2H. In this case, vesicles collapsed and re-assembled into nano-tubes. However, when addition of WP5 into the solution of 1H, the vesicles transformed into micelles, this is due to the formation of supramolecular amphiphile WP5&1H. Upon irradiation of WP5&1H with 365 nm light for 3 h, nano-ribbons observed instead of micelles in the solution. Notably, nanotubes from 2H could also transform into nano-ribbons after adding WP5. The self-assembly process and the resultant assemblies were characterized by TEM, SEM, DLS, SAXS and NMR technologies. Due to both CO2 and light are "green" for living organisms, we anticipated our system can offer the possibilities in "on demand" drug absorption and release.
关键词： Reversible conversion,Coumarin,Supramolecular assemblies,Amphiphiles,Pillar[5]arene
更新于2025-09-23 15:19:57
-
Characterization of tracers for two-color laser-induced fluorescence liquid-phase temperature imaging in sprays
摘要： The variation of the fluorescence spectral signature of tracer solutions with temperature enables temperature imaging measurements in liquids and sprays by simultaneously recording and rationing the fluorescence intensity detected in two separate wavelength channels. In this work, we recorded fluorescence spectra of ethanol-based solutions of nine laser dyes used as tracers (PTP, stilbene 1, coumarin 152, coumarin 153, rhodamine B, rhodamine 101, pyrromethene 597, DCM, and pyridine 1) after excitation at either 266, 355, or 532 nm (depending on the dye) for temperatures between 298 and 348 K (close to the boiling point of the solvent), and for concentrations (depending on dye) around 10 mg/l (i.e., ~ 10–5 mol/l). The influence of signal self-absorption was investigated for the tracers best suited for thermometry, rhodamine B and coumarin 152, where the latter is almost unaffected due to its large Stokes shift. In thin-film (100 μm) cells, possible concentration effects on the fluorescence spectrum were investigated in the absence of signal self-absorption in the 0.1–10 and 0.5–50 mg/l range for rhodamine B and coumarin 152, respectively. Sensitivities of the two-color intensity ratios were determined for two selected color detection channels for each tracer characterized by their center wavelength and spectral half width and conditioned on averaged intensities of larger than 10% of the spectral peak of their respective fluorescence spectrum. The use of coumarin 152 that showed the overall best spectroscopic properties was demonstrated for temperature imaging in a burning ethanol spray.
关键词： coumarin 152,rhodamine B,sprays,temperature imaging,two-color laser-induced fluorescence,tracers
更新于2025-09-23 15:19:57
-
Synthesis, electrochromic characterization and solar cell application of thiophene bearing alternating copolymers with azobenzene and coumarin subunits
摘要： In this study, azobenzene and coumarin functionalized thiophene comprising two copolymers (poly (4-((3000-hexyl-[2,20:50,200:500,2000-tetrathiophene] (cid:2) 30-yl)methoxy) - 2H-chromen-2-one (P1) and poly (1-(4-((4000-hexyl-[2,20: 50, 200: 500, 2000 - tetrathiophene] (cid:2) 30-yl) methoxy) phenyl) (cid:2)2-phenyldiazene) (P2)), were designed and synthesized according to the donor–acceptor (D–A) approach to investigate their electrochemical, optical and photovoltaic behaviors. Among the various copolymerization methods to obtain P1 and P2, Stille copolymerization reaction was preferred. The HOMO and LUMO values were determined via cyclic voltammetry (CV) as (cid:2)5.64 eV and (cid:2)3.76 eV for P1 and (cid:2)5.47 eV and (cid:2)3.83 eV for P2, respectively. The optical band gaps of the polymers for P1 and P2 were calculated as 1.88 eV and 1.64 eV using UV-VIS spectrophotometer. Electrochemical and spectroelectrochemical studies for synthesized copolymers support their usage in organic solar cell applications. The organic solar cells (OSCs) were designed using polymer as an electron donor group and PC60BM as an electron acceptor group. Performances of OSCs based on P1 and P2 were investigated with the device structure of ITO/PEDOT:PSS/ Polymer(P1/P2):PC60BM/LiF/Al. The preliminary solar cell results were reported here and studies are going on in our laboratories to increase the efficiency. The highest power conversion efficiency was obtained as 0.81% for P1 based device with 0.47 V open-circuit voltage (Voc) and 4.92 mA/cm2 current density (Jsc) values. The highest efficiency for P2 comprising device was found to be 0.96% under optimum conditions with 0.60 V and 4.98 mA/cm2, Voc and Jsc values, respectively.
关键词： Azobenzene,solar cell,coumarin,conducting polymers,thiophene bearing copolymers
更新于2025-09-23 15:19:57
-
Automated generation of photochemical reaction data by transient flow experiments coupled with online HPLC analysis
摘要： The automated generation and acquisition of large-scale reaction data is crucial to recent progress in organic synthesis and pharmaceutical process development. To follow reaction progress over time, time-series of reaction data can be generated by transient flow experiments, which allow to investigate reactions in a short transient period between two steady-state operations of a continuous-flow microreactor. The acquisition of analytical data in this short transient period, however, remains challenging since separation techniques like HPLC – though able to cope with highly complex samples – are typically regarded as too slow for the required acquisition rates. We break the longstanding coupling between the timescale of the continuous-flow experiment and the acquisition rate of the analytical method with the introduction of the multiple heart-cutting interface, which allows for sample parking prior to sample analysis. Transient flow experiments are presented for the [2+2] cycloaddition between 1-methyl-2-quinolinone and coumarin. Competing homo- and crossdimerization reactions are quantitatively investigated in systematic reaction parameter screenings with more than 400 data points. Results provide precious insights into this complex photochemical system – not only for reaction optimization, but also for a more profound understanding of the involved chemical processes.
关键词： quinolinone,online HPLC analysis,photochemical reaction data,homo- and crossdimerization reactions,[2+2] cycloaddition,coumarin,automated generation,transient flow experiments
更新于2025-09-23 15:19:57
-
Coumarin-Modified Graphene Quantum Dots as a Sensing Platform for Multicomponent Detection and Its Applications in Fruits and Living Cells
摘要： In this work, coumarin derivatives (C) are used to enhance the ?uorescence of graphene quantum dots (GQDs) by covalently linking the carboxyl groups on the edge of the GQD sheet. The as-synthesized coumarin-modi?ed graphene quantum dots (C-GQDs) have a uniform particle size with an average diameter of 3.6 nm. Simultaneously, the C-GQDs have strong ?uorescence emission, excellent photostability, and high ?uorescence quantum yield. C-GQDs and CN? can form a C-GQDs+CN? system due to deprotonation and/or intermolecular interactions. The introduced hydroquinone (HQ) is oxidized to benzoquinone (BQ), and the interaction between BQ and the C-GQDs+CN? system could lead to ?uorescence enhancement of C-GQDs. Meanwhile, the redox reaction between BQ and ascorbic acid (AA) can be used for quantitative detection of AA with CN? and HQ being used as substrates. Based on the above mechanism, C-GQDs are developed as a multicomponent detection and sensing platform, and the detection limits for CN?, HQ, and AA were 4.7, 2.2, and 2.2 nM, respectively. More importantly, satisfactory results were obtained when the platform was used to detect CN?, HQ, and AA in living cells and fresh fruits.
关键词： multicomponent detection,CN?,fluorescent probe,HQ,coumarin-modi?ed graphene quantum dots,AA
更新于2025-09-23 15:19:57
-
A highly selective “turn-on” fluorescent probe for detecting Cu2+ in two different sensing mechanisms
摘要： A new coumarin-derived hydrazone (1) has been developed as a “turn-on” fluorescent probe for the detection of Cu2+ in two different sensing mechanisms. In anhydrous acetonitrile, the strong fluorescence response of 1 to Cu2+ was mainly attributed to the chelation-controlled C=N isomerisation. Besides, S-donor is indispensable in protecting from the Cu2+-induced fluorescence quenching. In aqueous acetonitrile, 1 as a chemodosimeter can highly selectively sense of Cu2+, which was ascribed to the Cu2+-promoted cyclization reaction affording the strong fluorescent cyclization product (2). The proposed cyclization reaction was confirmed by the single-crystal structure of 2. Furthermore, 1 was utilized for imaging intracellular Cu2+ with good performance.
关键词： Live cell imaging,Fluorescent probe,Copper ion,Coumarin,Cyclization
更新于2025-09-23 15:19:57
-
A coumarin-based dual optical probe for homocysteine with rapid response time, high sensitivity and selectivity
摘要： In this study, a new coumarin-based fluorescent and chromogenic dual channel probe (DC) was used for the selective detection of homocysteine (Hcy) over other amino acids, especially for cysteine (Cys) and glutathione (GSH). When Hcy is present in the solution, the remarkable fluorescence enhancement and obvious blue shift in UV–vis spectra can be observed. In addition, the color change from purple to yellow can be observed clearly by unaided eyes. This probe DC has fast response time, excellent sensitivity and selectivity to Hcy. A linear relationship exists between the ratio of emissions at 486 and 625 nm, and Hcy can be detected in a wide concentration range (0 to 200 μM). The signal-to-background ratio of fluorescence at 486 nm can reach 8.4, and the detection limit is calculated to be 3.5 μM. The response mechanism is proved to be the Michael addition reaction by Hcy. Preliminary results on cell imaging enable the practical application of Hcy tracing in living cells.
关键词： Sensor,Fluorescent probe,dual optical probe,Coumarin,Homocysteine,Cell imaging
更新于2025-09-23 15:19:57
-
Design and synthesis of a novel colorimetric fluorescent probe for selective detection of sulfur dioxide in SH-SY5Y neuroblastoma cells and its application in Traditional Chinese Medicines
摘要： Sulfur fumigation has attracted more and more attention as one of the important post-harvest processing methods for some Traditional Chinese Medicines (TCMs) in the last decade. However, sulfur-fumigated TCMs have recently emerged as a controversial topic due to their potential detrimental effect on the safety and efficacy, as some sulfur-fumigated TCMs contain lots of sulfur dioxide derivatives. Additionally, high levels of the sulfur dioxide derivatives could cause some diseases and dangerous environmental pollutant. In this work, a fast response time, low limit of detection and high fluorescence quantum yield probe DTCC was designed and synthesized to detect SO2 derivatives based on coumarin-thiophene dye which was fused with a coumarin moiety and 2-thiophenecarboxaldehyde. Probe DTCC exhibited fast response time (less than 10 s), satisfactory selectivity for SO2 derivatives in the presence of other ROS and excellent sensitivity for SO2 derivatives with low limit of detection (0.23 μM) and widely linear range (0～100 μM). Furthermore, probe DTCC was successfully applied in fluorescent imaging in SH-SY5Y neurobalstoma cells with excellent membrane permeability and stability. It was also employed for monitoring the total SO2 derivatives in several real TCMs sample. These results illustrated that probe DTCC has an excellent capability for monitoring SO2 derivatives in living cells and real TCMs sample.
关键词： Fast responsive,Fluorescent probe,Coumarin scaffold,Bioimaging,Sulfur dioxide,Traditional Chinese Medicines
更新于2025-09-19 17:15:36