稀土发光探针检测羟基自由基

Due to the high oxidative potential of the hydroxyl radical (·OH), the accumulation of ·OH in tissues can cause inflammation, such as that in arthritis. Therefore, the development of ·OH detection with high efficiency and sensitivity is important for the treatment of related diseases. In this work, a cypate-modified core-shell NaErF4@NaLuF4 nanoprobe (csEr-Cy) was designed for detecting ·OH on the basis of a typical reaction between cypate and ·OH. The process resulted in the recovery of 654 nm upconversion luminescence emission of csEr because of a weakened inner filter effect (IFE) and Förster resonance energy transfer (FRET). The short-wavelength infrared (SWIR) emission at 1550 nm was not affected by ·OH addition; thus, enabling interference-free detection. Density functional theory (DFT) calculations were performed to explain the underlying mechanism. With the SWIR signal used as a reference for ·OH detection, the csEr-Cy nanoprobe showed higher sensitivity and penetration than visible reference. This method was successfully used in mice for the diagnosis of arthritis in vivo. Our results provide novel insights into improving the sensitivity of nanoprobes for molecule detection and disease diagnosis.

… to detect • OH, and the combination of upconversion luminescence and colorimetry should detect • … ICG and • OH, ICG-modified UCNP were designed as a probe with which to detect • …

… (21) Hydroxyl radical ( • OH) was generated in the Fenton system from ferrous ammonium sulfate and H 2 O 2 . (22) Peroxynitrite (NaONOO) was synthesized from sodium nitrite (0.6 M) …

… Schematic of a ratiometric fluorescent assay for the detection of hydroxy radical ( • OH) based … However, most of these fluorescent probes detect • OH with optical signal changes only in …

Molecular probes for the detection of hydroxyl radical (HO•) by time-delayed luminescence spectroscopy directly in water at neutral pH with high sensitivity and selectivity are presented. The bimolecular probes consist of a lanthanide complex with open coordination sites and a reactive pre-antenna composed of an aromatic acid or amide; the latter binds to and sensitizes terbium emission upon hydroxylation by HO•. These probes exhibit long luminescence lifetimes compatible with time-delayed measurements that remove interfering background fluorescence from the sample. Six different reactive pre-antenna (benzoate, benzamide, isophthalate, isophthalamide, trimesate, and trimesamide) and two different terbium complexes (Tb-DO3A and Tb-DO2A) were evaluated. Of these the trimesamide/Tb-DO3A system enables the most sensitive detection of HO• with a ca. 1000-fold increase in metal-centered time-delayed emission upon hydroxylation of the pre-antenna to 2-hydroxytrimesamide. Excellent selectivity for both the trimesamide/Tb-DO3A and trimesate/Tb-DO3A systems over other reactive oxygen and nitrogen species are observed. Notably, the increase in metal-centered luminescence intensity is not associated with a decrease in the hydration number (q) of Tb-DO3A, suggesting that the antenna is interacting with the lanthanide via a second sphere coordination environment or that coordination by the antenna occurs by displacement of one or more of the carboxylate arms of DO3A. Formation of a weak ternary complex Tb-DO3A•hydroxytrimesamide was confirmed by temperature-dependent titration and a decrease in Kapp with increasing temperature.

… distance and a pronounced luminescence quenching yield (97%)… OH (with limit of quantitation (LOQ) of 0.10 fM). With good biocompatibility, low biotoxicity, and enhanced luminescence …

… fluorescent probes ascribed from the short excitation light limits their extensive applications. Rare earth … and sensitive hydroxyl radical nanoprobe based on the luminescence resonance …

… 1, for the nitroxide radical does not trap the hydroxyl radical directly. In this present work, the response of 1 to hydroxyl radicals was explored. The hydroxyl radicals were generated via …

… in luminescence quantum yield with a long luminescence lifetime (2.76 ms). The luminescence response of the probe to hydroxyl radical is … For loading the probe into the living cells, the …

… sphere water also creates luminescence quenching, found as a luminescence enhancement upon drying or upon changing solvent, or when comparing luminescence intensities of …

… excited luminescence resonance … probe to monitor the •OH levels in a lipopolysaccharide (LPS) model of acute inflammation. It was reported that the concentration of hydroxyl radical in …

… In this perspective, we focus on the molecular design strategies for the construction of photoluminescent probes to detect 1 O 2 , OH, and the highly oxidizing iron–oxygen species. …

… Moreover, we demonstrate the ratiometric luminescence detection of •OH generated from … Furthermore, cellular reactive oxygen species determination by singlet oxygen sensor green …

… luminescent sensors for cellular imaging, which interest us in this review. Lanthanide complexes … species other than hydroxyl radicals does not produce the ortho-hydroxylated acids, our …

Histopathological hallmarks of Alzheimer’s disease (AD) are intracellular neurofibrillary tangles and extracellular formation of senile plaques composed of the aggregated amyloid‐beta peptide along with metal ions (copper, iron or zinc). In addition, oxidative stress is considered as an important factor in the etiology of AD and a multitude of metalloproteins and transporters is affected, leading to metal ion misregulation. Redox‐active metal ions (e.g., copper) can catalyze the production of reactive oxygen species (ROS) in the presence of molecular oxygen and a reductant such as ascorbate. The ROS thus produced, in particular the hydroxyl radical which is the most reactive one, may contribute to oxidative stress conditions. Thus, detecting ROS in vivo or in biological models of AD is of interest for better understanding AD etiology. The use of biocompatible and highly specific and sensitive probes is needed for such a purpose, since ROS are transient species whose steady‐state concentrations are very low. Luminescent lanthanide complexes are sensitive probes that can meet these criteria. The present review focuses on the recent advances in the use of luminescent lanthanide complexes for ROS biosensing. It shows why the use of luminescent lanthanide complexes is of particular interest for selectively detecting ROS ( O2·‐ , HO•, 1O2, H2O2, etc.) in biological samples in the µM‐nM range. It particularly focuses on the most recent strategies and discusses what could be expected with the use of luminescent lanthanide complexes for better understanding some of the molecular mechanisms underlying the development of Alzheimer’s disease.

… of highly reactive oxygen species (HOCl and • OH). (54) Because AMTTA-Ln 3+ lacks the recognition specificity to distinguish HOCl and • OH radicals, in this work, a novel dual-…

Hydroxyl radical (•OH), a highly reactive oxygen species (ROS), is assumed as one of the most aggressive free radicals. This radical has a detrimental impact on cells as it can react with different biological substrates leading to pathophysiological disorders, including inflammation, mitochondrion dysfunction, and cancer. Quantification of this free radical in-situ plays critical roles in early diagnosis and treatment monitoring of various disorders, like macrophage polarization and tumor cell development. Luminescence analysis using responsive probes has been an emerging and reliable technique for in-situ detection of various cellular ROS, and some recently developed •OH responsive nanoprobes have confirmed the association with cancer development. This paper aims to summarize the recent advances in the characterization of •OH in living organisms using responsive nanoprobes, covering the production, the sources of •OH, and biological function, especially in the development of related diseases followed by the discussion of luminescence nanoprobes for •OH detection.

In natural waters, hydroxyl radical (OH) can initiate many free radical-induced reactions, oxidizing various inorganic and organic compounds through electron transfer reactions, dehydrogenation reactions, addition reactions, and self-quenching reactions. However, due to its extremely low concentration and short lifetime in natural waters, studies on the quantitative measurement of OH levels are insufficient. In this work, we developed the first quinolinium-based fluorescence probe containing fluoride substituted donor that could detect hydroxyl radicals in the water system. This probe exhibits excellent selectivity towards OH with a large Stokes shift (114 nm) and 23-fold enhancement in fluorescence. Additionally, this probe has been proven to be low toxicity and applied to detect OH in living cells, zebrafish, and natural water samples with good recovery (over 92 %).

… This review has covered the fluorescent and luminescent probes developed in the past few years for the detection of the hydroxyl radical with a view to highlight their design, detection …

Ratiometric lanthanide coordination polymers (Ln-CPs) are advanced materials that combine the unique optical properties of lanthanide ions (e.g., Eu3+, Tb3+, Ce3+) with the structural flexibility and tunability of coordination polymers. These materials are widely used in biological and chemical sensing, environmental monitoring, and medical diagnostics due to their narrow-band emission, long fluorescence lifetimes, and excellent resistance to photobleaching. This review focuses on the composition, sensing mechanisms, and applications of ratiometric Ln-CPs. The ratiometric fluorescence mechanism relies on two distinct emission bands, which provides a self-calibrating, reliable, and precise method for detection. The relative intensity ratio between these bands varies with the concentration of the target analyte, enabling real-time monitoring and minimizing environmental interference. This ratiometric approach is particularly suitable for detecting trace analytes and for use in complex environments where factors like background noise, temperature fluctuations, and light intensity variations may affect the results. Finally, we outline future research directions for improving the design and synthesis of ratiometric Ln-CPs, such as incorporating long-lifetime reference luminescent molecules, exploring near-infrared emission systems, and developing up-conversion or two-photon luminescent materials. Progress in these areas could significantly broaden the scope of ratiometric Ln-CP applications, especially in biosensing, environmental monitoring, and other advanced fields.

… luminescence technique. Sensitive and selective time-gated luminescence detection of hydroxyl radicals … a sensitive response to thiyl radicals, and that the off-on luminescent and on-off …

… harnessed in the design of classical fluorescent sensors and are used in the measurement … Overall, both the ligand-based fluorescence and the delayed lanthanide luminescence may …

The principles of the design of responsive luminescent probes and sensors based on lanthanide emission are summarised, based on a mechanistic understanding of their mode of action. Competing kinetic pathways for deactivation of the excited states that occur are described, highlighting the need to consider each of the salient quenching processes. Such an analysis dictates the choice of both the ligand and its integral sensitising moiety for the particular application. The key aspects of quenching involving electron transfer and vibrational and electronic energy transfer are highlighted and exemplified. Responsive systems for pH, pM, pX and pO2 and selected biochemical analytes are distinguished, according to the nature of the optical signal observed. Signal changes include both simple and ratiometric intensity measurements, emission lifetime variations and the unique features associated with the observation of circularly polarised luminescence (CPL) for chiral systems. A classification of responsive lanthanide probes is introduced. Examples of the operation of probes for reactive oxygen species, citrate, bicarbonate, α1-AGP and pH are used to illustrate reversible and irreversible transformations of the ligand constitution, as well as the reversible changes to the metal primary and secondary coordination sphere that sensitively perturb the ligand field. Finally, systems that function by modulation of dynamic quenching of the ligand or metal excited states are described, including real time observation of endosomal acidification in living cells, rapid urate analysis in serum, accurate temperature assessment in confined compartments and high throughput screening of drug binding to G-protein coupled receptors.

… Fluorescence technique was applied to the detection of radical dot OH radicals formed on a photo-… [12] reported that there existed an optimum doping content of rare earth ions in TiO 2 …

… provides a means for extremely sensitive detection of Tb(III) and also of … hydroxyl radicals. Therefore, we believe that a parallel solid-state mechanism of generation of hydroxyl radicals …

The detection of hydroxyl radicals (OH) is often required in environmental governance and biomedicine. To enhance the sensing accuracy and stability, this study constructed a temperature-corrected and ratio-calibrated sensor for sensitive hydroxyl radical detection by loading upconversion nanomaterials and dye molecules methylene blue (MB) on optical fibers. Based on the multicolor emission of upconversion materials and the OH trapping of MB molecules, the <inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>OH detection and real-time temperature correction are achieved. The results show that the MB molecules can react sensitively and specifically with <inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>OH. Under near-infrared excitation, precise information on temperature and MB absorption is obtained by detecting the ratio of multiple characteristic wavelengths of light, thus enabling the quantitative detection of <inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>OH. The limit of detection (LOD) of <inline-formula> <tex-math notation="LaTeX">$\cdot $ </tex-math></inline-formula>OH can be reach as low as <inline-formula> <tex-math notation="LaTeX">$0.26~\mu $ </tex-math></inline-formula>M. The method shows the advantages of high sensitivity, low cost, and ease of miniaturization and is expected to be applied in environmental and biomedical fields.

Hydroxyl radical (·OH) can rapidly react with biological macromolecules, organic and inorganic substances on account of its strong oxidizing property, so it is widely used in sewage treatment, chemiluminescence analysis, biological macromolecule modification and other fields. The strengthening effect of Hydrodynamic cavitation on chemical reactions depends on the number of free radicals initiated by cavitation. These free radicals are highly reactive and react rapidly with pollutants and other species in wastewater. Therefore, the systematic summary of detection methods of hydroxyl radical and the description of its advantages and disadvantages can provide technical support for scientific researchers, and guides the research in the future.

… radical •OH in situ in tumor. This photosensitizer consists of NaYbF 4 :Tm@NaYF 4 upconversion nanoparticles (… serve as a probe for the specific detection of •OH in solid tumors in vivo. …

Reactive oxygen species (ROS) and reactive nitrogen species (RNS) are essential oxidative metabolites of organisms, which are closely related to physiological, pathological and pharmacological processes. The accurate detection of ROS/RNS is important for the understanding of biological processes, monitoring of pharmacological effects, and predicting the course of disease. The recently developed NIR nanoprobes based on upconversion nanoparticles (UCNPs) hold great prospects in sensitive and deep-tissue detection of ROS/RNS, and considerable progress has been achieved so far. In this review, we systematically summarize the up-to-date advances of UCNPs-based NIR probes for ROS/RNS sensing, and the potential challenges and perspectives for further research are also highlighted. We envision that such a research field will have a bright future for modern biomedical applications.

Significant progress on upconversion‐nanoparticle (UCNP)‐based probes is witnessed in recent years. Compared with traditional fluorescent probes (e.g., organic dyes, metal complexes, or inorganic quantum dots), UCNPs have many advantages such as non‐autofluorescence, high chemical stability, large light‐penetration depth, long lifetime, and less damage to samples. This article focuses on recent achievements in the usage of lanthanide‐doped UCNPs as efficient probes for biodetection since 2014. The mechanisms of upconversion as well as the luminescence resonance energy transfer process is introduced first, followed by a detailed summary on the recent researches of UCNP‐based biodetections including the detection of inorganic ions, gas molecules, reactive oxygen species, and thiols and hydrogen sulfide.

… for selective detection of hydroxyl radical ( radical dot OH) and … Additionally, the emission peaks of upconversion nanoparticles … In this work, we also used the hydroxyl radical–luminol …

… The procedure was based on the hydroxyl radicals (·OH), … ,Er upconversion nanoparticles (UCNPs). Based on the property of Mn 2+ -doped NaYF 4 :Yb,Er upconversion nanoparticles, …

Conventional electrochemiluminescence (ECL) systems typically rely on coreactants, such as hydrogen peroxide or dissolved oxygen, to generate reactive oxygen species (ROS), which are essential for effective light emission. However, these coreactants are inherently limited by self-decomposition and solubility constraints, which can hinder the detection accuracy and light emission efficiency of ECL systems. In this work, we propose an innovative method that eliminates the need for coreactants by utilizing inverse opal TiO2 (IO-TiO2) coupled with upconversion nanoparticles (UCNPs) as a coreaction accelerator. By harnessing near-infrared (NIR) irradiation, UCNPs efficiently convert this light into ultraviolet (UV) light, stimulating IO-TiO2 to generate ROS through water oxidation. The generated ROS subsequently reacts with luminol anion radicals, producing robust ECL emission while eliminating interference from luminescence caused by coreactants. Electron paramagnetic resonance (EPR) results confirm the generation of hydroxyl (•OH), singlet oxygen (1O2), and superoxide anion radicals (O2•-) during the electrochemical water oxidation process, which ensured the feasibility of the experimental approach. To demonstrate the practical application of this method, human chorionic gonadotropin (HCG) was selected as a model analyte. This proposed ECL immunoassay exhibited high sensitivity and stability in detecting HCG, with a linear range of 4 pg/mL to 1 μg/mL and a low limit of detection (LoD) of 1.33 pg/mL (S/N = 3). This breakthrough offers a promising avenue for developing ECL systems that are more sensitive, efficient, and highly versatile, expanding the range of applications in bioanalysis and environmental monitoring.

… nanoprobe utilizing upconversion nanoparticles (UCNPs) … allowed ratiometric UCL emission as the detection signal. It is of … (hypochloride-ClO − , hydroxyl radical-·OH, and peroxynitrite-…

We report on strong X-ray-induced hydroxyl radical (. O H ) generation in an aqueous solution containing UV light pre-treated GdYVO4:Eu3+ nanoparticles (L-GdYVO). The methods of optical spectroscopy were used to detect . O H in the solutions. The complex nature of the mechanism of . O H generation has been revealed and discussed. The experimental data obtained indicate that the mechanism of . O H generation is associated with two main processes: (i) direct . O H generation with the participation of thermalized h+ formed at X-ray irradiation, and (ii) X-ray-facilitated jumps of h+ formed in the nanoparticles’ (NPs’) valence band at UV light pre-treatment and trapped in local levels formed by random scattering potential. At the same time, for GdYVO4:Eu3+ nanoparticles, which were not exposed to UV light before the X-ray irradiation (D-GdYVO), a strong radioprotective effect ascribed to the electron-donation properties of V4+ ions was observed. Thus, depending on the pre-treatment condition, we can change the redox properties of GdYVO4:Eu3+ NPs in an opposite direction, which makes this nanomaterial a unique theranostic agent for radiation therapy (RT) enhancement, allowing the problem of radiation therapy (RT)-resistant hypoxic tumours to be overcome.

… We have developed new kinds of europium(III) CPs used as fluorescence probes for … of europium(III) CPs is simple and efficient by mixing the flexible TDA ligand and europium(III) in …

… elevating the level of hydroxyl radical in aqueous solutions … oxide nanocrystals, as terbium oxide NPs allow measuring … cerium oxide nanocrystals, terbium luminescence does not …

… showing cathodic electrogenerated luminescence (EL) at an … and hydroxyl radicals, sulfate radicals or dichlorine radical ions … atoms and hydroxyl radicals as the primary radicals using a …

A nanosized Tb-MOF with a boronic acid ligand can be used for the highly sensitive detection and scavenging of ROS in living cells.

The development of chemosensors for the detection of hydroxyl radicals (HO•) is a challenging task since HO• has an exceptionally short lifetime (in vivo half-life of 1 ns). In this work, we have designed and synthesized a versatile probe, viz. Tb@rGO, for the detection of HO• amongst the biologically important ions and reactive oxygen species (ROS). Our design is based on covalent conjugation of reduced graphene oxide (rGO) with terbium (III)-1,4,7,10-tetraazacyclododecane-1,4,7-triacetic acid (Tb-DO3A). Tb@rGO is characterized by traditional spectroscopic methods including XRD, SEM, TEM, and zeta potential analysis. Furthermore, we elaborate the photophysical properties of Tb@rGO. Accordingly, our results attest that Tb@rGO has unique luminescence features, rendering it highly effective in the detection of HO•. Remarkably, Tb@rGO is highly selective to HO• among many biologically important species in 0.1 M pH 7.4 phosphate buffered saline solution. It is also noteworthy that the limit of detection (LOD) is 0.92 M for HO•. Therefore, this novel material hold promises as selective turn-off luminescent HO• probe.

… luminescence for the case of STL in the suspensions of crystals. While continuing these studies, here we report about detection of OH radical and atomic oxygen luminescence … /terbium …

… Namely, OH radical line of small intensity at 309 nm is observed in the short-wave range of … and comparing them with the luminescence spectra of OH and OD radicals. They have been …