Ratiometric Fluorescent Probe For Detection Research Articles

Coumarin-hemicyanine-based ratiometric fluorescent probes for detection of strong acidity

Fluorescent probes for determination of strongly acidic pH values are urgently needed, especially the ones with ratiometric signal changes. Here, two fluorescent probes (CP and CyC) based on coumarin-hemicyanine were synthesized. Both probes emitted red fluorescence under weakly acidic to weakly alkaline conditions, whereas blue fluorescence under strongly acidic conditions. Notably, probe CP displayed good stability, water solubility, anti-interference ability, repeated utilization and instant response. Encouraged by the good performance, probe CP based test strips were used to indicate the pH of aqueous solutions, and to detect HCl or NH3 vapor in air reversibly.

Aggregation-induced-emission red carbon dots for ratiometric sensing of norfloxacin and anti-counterfeiting

The detection of trace antibiotic residues holds significant importance because it’s related to food safety and human health. In this study, we developed a new high-yield red-emitting carbon dots (R-CDs) with aggregation-induced emission properties for ratiometric sensing of norfloxacin. R-CDs were prepared in 30 min using an economical and efficient microwave-assisted method with tartaric acid and o-phenylenediamine as precursors, achieving a high yield of 34.4 %. R-CDs showed concentration-dependent fluorescence and aggregation-induced-emission properties. A ratiometric fluorescent probe for detecting the norfloxacin was developed. In the range of 0–40 μM, the intensity ratio of two emission peaks (I445 nm/I395 nm) towards norfloxacin show good linear relationship with its concentrations and a low detection limit was obtained (36.78 nM). In addition, complex patterns were developed for anti-counterfeiting based on different emission phenomenon at different concentrations. In summary, this study designed a novel ratiometric fluorescent probe for detection of norfloxacin, which greatly shortens the detection time and improves efficiency compared with high-performance liquid chromatography and other methods. The study will promote the application of carbon dots in anti-counterfeiting and other related fields, laying the foundation for the preparation of low-cost photosensitive anti-counterfeiting materials.

Pyrene and Eu3+ modified mesoporous silica used as a fluorescent probe for ratiometric detection of tetracycline antibiotics

The detection of residual tetracycline antibiotics (TCs) in the aquatic environment is important because of the irreversible damage of TCs to the ecosystem and human health. Considering the photostability, sensitivity, and accuracy of the detection systems, mesoporous SBA-15 silica material was an ideal support matrix for improving photostability because it can protect the optical properties of fluorescent signals. To achieve ratiometric detection (with sensitivity and accuracy), pyrene and Eu3+ as two fluorescent signals were implemented into SBA-15, and an organic–inorganic hybrid fluorescent nanoprobe Py/EDTA-SBA-15@Eu3+ was constructed. In the presence of TCs, the red emission of Eu3+ in the nanoprobe was sensitized, and the fluorescence resonance energy transfer occurred from pyrene to Eu3+, resulting in the increased emission of Eu3+ at 617 nm and the decreased emission of pyrene at 384 nm. By monitoring the fluorescent intensity changes at 617 and 384 nm (F617/F384), the nanoprobe achieved the ratiometric detection of oxytetracycline (OTC) and tetracycline (TC) in the range of 0.20–80 and 0.40–80 μM, respectively, with detection limits of 0.18 nM for OTC and 5.83 nM for TC. In addition, the practical application of the nanoprobe was validated in tap water and honey samples.

A Readily Available Red‐Emitting Methylthio‐Substituted Salicylaldehyde Azine with AIE Feature for Ratiometric Detection of HClO

AbstractDeveloping a simple, selective, and rapid reliable method to monitor hypochlorous acid (HClO) in vivo is very meaningful due to its important physiological and pathological functions. In this research, a novel AIE based fluorescent probe for ratiometric detection of HClO was fabricated by a simple one‐step synthesis, in which the methyl sulfide group and salicylaldehyde azine serve as the recognition unit and fluorophore, respectively. This probe was visible‐light‐excitable, and showed a palpable aggregation‐induced emission into the red region with high stability to Cu2+ and pH. Oxidation of the methyl sulfide group can be achieved rapidly and specifically by HClO in physiological condition, which enables it to display a rapid, ratiometric fluorescent response to HClO with high selectivity over other biologically pertinent species. By exploiting the probe‐based tool, we successfully validated its practical utility in selectively recognizing HClO in living cells via ratiometric fluorescence signals, thereby providing a potential method for investigating the relevant functions of HClO in biosystems.

A unique ratiometric fluorescent probe for detection of SO2 derivatives in living cells and real food samples

Abnormal levels of SO2 in organisms can cause cardiovascular disease and respiratory allergies. In addition, the amount of SO2 derivatives used as food preservatives is strictly controlled, and excessive addition can also be harmful to health. Therefore, it is essential to develop a highly sensitive method for the detection of SO2 and its derivatives in biological systems and real food samples. In this work, a new fluorescent probe (TCMs) with high selectivity and sensitivity for the detection of SO2 derivatives was reported. The TCMs could quickly identify SO2 derivatives. It has been successfully used to detect exogenous and endogenous SO2 derivatives. Furthermore, the TCMs has high sensitivity to SO2 derivatives in food samples. Moreover, the prepared test strips could be evaluated for the content of SO2 derivatives in aqueous solutions. This work provides a potential chemical tool to detect SO2 derivatives in living cells and real food samples.

A hemicyanine-based fluorescent probe for ratiometric detection of ClO- and turn-on detection of viscosity and its imaging application in mitochondria of living cells and zebrafish

A water-soluble fluorescent probe 1 based on chromene-hemicyanine has been developed, that exhibits ratiometric fluorescent response toward hypochlorite (ClO-) with the LOD (0.082 μM), and “turn-on” response to viscosity changes. Due to low cytotoxicity and good biocompatibility, probe 1 used to monitor hypochlorous acid and viscosity in mitochondria of living cells and zebrafish.

A novel colorimetric and ratiometric fluorescent probe for detection of Cu2+ with large stokes shift in complete aqueous solution

A novel colorimetric and ratiometric fluorescent probe 1 for Cu2+ was designed and synthesized. 1 exhibited maximum absorption and fluorescence emission peaks at 385 nm and 495 nm respectively, with large Stokes shift of 110 nm. In sensing of Cu2+, the maximum absorption and fluorescence emission peaks generated bathochromic shift to 415 nm and 560 nm respectively, due to the Cu2+-induced hydrolysis reaction of the picolinate moiety in 1. Meanwhile, the solution of 1 turned from pale yellow to yellow in visible light and from pale green to orange under a 365 nm UV lamp. 1 displayed remarkable change in the ratio (F560 nm/F495 nm) of the fluorescence intensity (R/R0 up to 23-fold), high sensitivity (detection limit of 0.62 μM), fast response time (within 2 min), and excellent selectivity for Cu2+ over other metal ions in complete aqueous solution.

A 'double locked' ratiometric fluorescent probe for detection of cysteine in a viscous system and its application in cancer cells.

Intracellular viscosity is a physicochemical property that regulates the consequences of several biological progressions. Cysteine (Cys) is an important signaling molecule that commands many cellular activities, such as antioxidant generation. Predicting that both may be interconnected with a diversity of pathological processes, their contemporaneous measurement would be valuable for studying the pathological ailment of cells. Herein, we have synthesized a 'double locked' probe, acrylic acid 6-[4-(2-benzothiazol-2-yl-2-cyano-vinyl)-phenyl]-naphthalen-2-yl ester (ABN) for the detection of Cys in a viscous medium and explored its application to living cells that were exposed to dexamethasone to regulate the intracellular viscosity level. ABN displayed a satisfactory ratiometric (blue to orange) fluorescence response in solution and in living cells when Cys and viscosity coexisted. A turn-on fluorescence signal was visualized when the probe was individually treated with Cys and glycerol (a standard viscosity source). Therefore, we propose that ABN is a fluorescent probe that permits the monitoring of variations in intracellular viscosity and Cys levels in a biological environment, and it can be utilized in innumerable cellular damage models.

A novel red AIE fluorescent probe for ratiometric detection of carbon monoxide in vitro and in vivo.

As a significant signaling gas molecule, carbon monoxide (CO) has a crucial impact on various physiological and pathological processes in organisms, particularly in oxidative stress processes. Hence, designing and synthesizing a fluorescent probe that can effectively image CO in vivo holds immense significance. In this work, under the guidance of density functional theory (DFT) and time-dependent density functional theory (TDDFT), we designed and synthesized a red aggregation-induced emission (AIE) fluorescent probe THBTA-CO for CO detection and imaging. The fluorescent probe displayed green fluorescence emission at 535 nm before the CO response. However, upon CO response, with the involvement of Pd2+, the probe emitted red fluorescence at 630 nm. Furthermore, we successfully demonstrated the potential of THBTA-CO in visualizing both exogenous and endogenous CO in living cells. Significantly, THBTA-CO was effectively employed to image CO in lipopolysaccharide (LPS)-induced oxidative stress in mice. These findings convincingly establish THBTA-CO as a promising fluorescent probe for CO sensing and imaging, thereby facilitating a better understanding of CO's role in biomedical research.

One-step synthesis of a pH switched pyrene-based fluorescent probe for ratiometric detection of HS- in real water samples.

Only a few probes are suited for highly acidic environments and sensitive to pH values below 4. Thus, finding a solution for detecting strong acidic (pH value below 2) conditions is still challenging. Herein, we constructed and created a pH-switched fluorescent probe based on pyrene and a heteroatom containing pyridine unit. When exposed to acidic environments (pH 2.0), the probe's fluorescence redshifted with distinct colour and fluorescence changes owing to protonation on the nitrogen atom containing pyridine moiety, which could be deprotonated by HS- selectively compared to other competing analytes. Pyr can detect HS- with a rapid response within 5 s and showed very good quantum yield under acidic environments. The sensing mechanism was confirmed by Density Functional Theory (DFT) studies using the B3LYP and 6-31G+ (d) basis sets. Furthermore, the probe was utilized to monitor HS- in actual water samples and identify H2S gas by a simple paper strip test.

A simple highly selective ratiometric fluorescent probe for detection of peroxynitrite and its bioimaging applications

Peroxynitrite (ONOO−), a potent oxidant, plays an important regulation role in different physiopathological processes. Its overproduction can potentially cause several diseases. Therefore, being able to accurately and selectively monitor ONOO− could help elucidate the interaction and function of ONOO− in physiological and pathological processes. Herein, a novel naphthalimide derived ratiometric fluorescent probe was successfully designed and synthesized for monitoring ONOO− in RAW 264.7 macrophage cells and zebrafish. The probe showed highly selective towards ONOO− with satisfactory sensitivity (detection limit: 0.32 μM) and a significant 15 - fold enhancement of fluorescence ratio accompanied with a large blue shift of 110 nm. In addition, further biological experimental studies showed that the probe could track ONOO− in RAW 264.7 macrophage cells and zebrafish animal models with specific sensitivity and reliability. Therefore, the probe can be expected to be a biological tool for developing the role of ONOO− in physiological systems in the future.

Construction of a bi-functional ratiometric fluorescent probe for detection of endoplasmic reticulum viscosity and ONOO- in cells and zebrafish

Viscosity and ONOO- are two important factors that affect the physiological activities and functions of endoplasmic reticulum (ER). Therefore, the detection of changes in viscosity and ONOO- levels is important to the study of related physiological and pathological processes. In this work, a new bi-functional fluorescent probe WND-1 for simultaneous detection of ER viscosity and ONOO- fluctuations in different channels was developed. The novel probe has good viscosity responsiveness. With the increase of viscosity, the ratio of fluorescence intensity (I638/I453) showed a good linear correlation with viscosity log values. In addition, the probe also has the ability to specifically detect ONOO- changes, and its limit of detection (LOD) value was 0.93 μM. WND-1 also has the advantages of high anti-interference, low cytotoxicity, good ER localization and rapid response. Notably, it not only can be used for ratiometric fluorescence detection of viscosity in cells and zebrafish, but also can simultaneously detect viscosity and ONOO- in different channels. Additionally, with WND-1, we also found that ONOO- could induce an increase in viscosity in the ER. This may help to facilitate the study of related physiopathological processes.

An amphiphilic ratiometric fluorescent probe with aggregation-induced emission feature for specific detection of hypochlorite in aqueous solution and living cells

Hypochlorite (ClO−) as one of reactive oxygen species (ROS), that has been widely used in our daily life and played a crucial role in immune function systems of living organisms. However, due to the hydrophobic nature of most fluorescent probes, direct utilization of these probes for detection of ClO− in biological systems has demonstrated to be problem. In this work, hydrophilic amino-terminated polyethylene glycol (PEG-NH2) and the organic dye (named as TPAMA) with aggregation-induced emission (AIE) feature were conjugated together using hexachlorocyclotriphosphazene (HCCP) as linking agent. The resultant probe (named as TPAMA-HCCP-PEG) was examined as ratiometric fluorescent probe for detection of ClO− in pure aqueous solution by taking advantage of its amphiphilic property. After adding ClO−, the fluorescence of TPAMA was quickly quenched, therefore it can be used for sensing ClO− with high sensitivity and selectivity. The mechanism was attributed to the reaction of TPAMA with ClO−, resulting in a blue-shift in absorbance and fluorescence emission. The potential of TPAMA-HCCP-PEG for sensing ClO− in biological systems was also evaluated further. Results showed that TPAMA-HCCP-PEG could form highly dispersible nanoparticles in aqueous solution and displayed low cytotoxicity towards model cancer cell lines, making it promising for monitoring ClO− in living systems. We believe this work will provide a general tool for fabrication of fluorescent probes suitable for visual detection various molecules with important biological roles.

Pyridine salts and aliphatic chains regulating membrane-targeted ratiometric fluorescence probe for detection of SO2 in living cells

Cell membrane is the barrier between cell and environment, which is an important structural basis for maintaining cell environment stability and regulating cell normal life activities. There are important active molecules in the cell membrane, so it is of great biological and medical significance to explore the physiological functions of active molecules in the cell membrane. In this work, probe that co-regulating cell membrane targeting by pyridine salts and lipid chains was developed. In this probe, using pyridine salt as receptor and coumarin derivatives as donor constructed a ratiometric fluorescent probe MCP based on ICT for specific recognition of SO2 derivatives. MCP was selected the cyanide group as the SO32− response site, and the introduction of pyridine propyl, which regulates hydrophobicity, so as to achieve efficient targeting of cell membranes. MCP showed high sensitivity and selectivity for SO32−. Moreover, MCP showed a fast response time (30 s) and red fluorescence emission wavelength (645 nm). In addition, MCP can successfully applying to detect endogenous SO2 on the cell membranes.

A quinoline-coumarin near-infrared ratiometric fluorescent probe for detection of sulfur dioxide derivatives

Sulfur dioxide derivatives (HSO3− and SO32−) play an important role in food preservative, antibacterial, antioxidant and other aspects, so it is urgent for us to develop more efficient detection methods to broaden their application in biochemical research and related disease diagnosis. Fluorescent probes are of particular interest because of their simplicity and high temporal and spatial resolution. Herein, we constructed a new near-infrared (NIR) fluorescence probe, CQC, composed of coumarin fluorophore and quinoline fluorophore, for detecting SO2 derivatives. The near-infrared emission probe CQC with a large Stokes shift (260 nm) not only kept the distance between the two emission peaks large enough (165 nm), but also had a particularly high energy transfer efficiency (99.5%), and was particularly sensitive to the detection of HSO3−/SO32− (LOD: 0.1 μM). The powerful probe CQC succeeded in real-time visualizing endogenous HSO3−/SO32− in living cells.

A ratiometric fluorescent probe for detection of γ-glutamyl transpeptidase in blood serum and living cells

γ-Glutamyl transpeptidase (GGT) is one of the biomarker of cancer, hepatitis, and numerous other diseases. The accurate analysis of GGT is useful for the early diagnosis of these diseases. In this work, Probe 1, a ratiometric fluorescent probe based on 2,3,5,6-tetrafluoroterephthalonitrile, was designed for GGT detection. The results indicated that Probe 1 can sensitively and selectively detect GGT in phosphate buffered solution and complex biological systems (e.g., blood serum). Furthermore, Probe 1 has been successfully applied for ratiometric imaging of GGT in cancer cells and normal cells.

A novel ratiometric fluorescent probe for detection of l-glutamic acid based on dual-emission carbon dots

In this article, we report for the first time the use of a dual-emission carbon dots (CDs) with orange-yellow fluorescence for the detection of l-glutamic acid (L-Glu). The CDs was synthesized through a facile strategy of one-pot hydrothermal route using o-phenylenediamine (oPD) and oxalic acid. The CDs exhibit two fluorescence emission peaks around 453 nm and 560 nm when the excitation wavelength is at 390 nm. In the existence of L-Glu the fluorescence at 560 nm was decreased, whereas the fluorescence at 453 nm was constant. The fluorescence intensity ratio at 560 nm and 453 nm (F560/F453) expressed two great linear relationships in the L-Glu concentration range from 0 to 200 μM and 200–400 μM, respectively, with a detection limit (LOD) of about 0.085 μM. In addition, it was used to analyze L-Glu in fetal bovine serum samples successfully, which recoveries were ranging from 97.07 to 103.7%. Those results demonstrate CDs can be further explored in biomedicine studies.

Construction of a Bi-Functional Ratiometric Fluorescent Probe for Detection of Endoplasmic Reticulum Viscosity and Onoo- in Cells and Zebrafish

Construction of a Bi-Functional Ratiometric Fluorescent Probe for Detection of Endoplasmic Reticulum Viscosity and Onoo- in Cells and Zebrafish

A new chromone-based fluorescent probe for ratiometric detection of Pd2+

A new chromone-based fluorescent probe (HMPM) is developed for the selective detection of Pd2+.

A Novel Ratiometric Fluorescence Probe for Detection of Copper(Ii) or Silver(I) Based on Assembling Dye Doped Silica Core-Shell Nanoparitcles with Gold Nanoclusters

A Novel Ratiometric Fluorescence Probe for Detection of Copper(Ii) or Silver(I) Based on Assembling Dye Doped Silica Core-Shell Nanoparitcles with Gold Nanoclusters