Probe For Detection Of Nitric Oxide Research Articles

Ferrocene probe-assisted fluorescence quenching of PEI-carbon dots for NO detection and the logic gates based sensing of NO enabled by trimodal detection

Our research demonstrates the effectiveness of fluorescence quenching between polyethyleneimine functionalised carbon dots (PEI-CDs) and cyclodextrin encapsulated ferrocene for fluorogenic detection of nitric oxide (NO). We confirmed that ferrocene can be used as a NO probe by observing its ability to quench the fluorescence emitted from PEI-CDs, with NO concentrations ranging from 1 × 10–6 M to 5 × 10–4 M. The photoluminescence intensity (PL) of PEI-CDs decreased linearly, with a detection limit of 500 nM. Previous studies have shown that ferrocene is a selective probe for NO detection in biological systems by electrochemical and colorimetric methods. The addition of fluorogenic NO detection using ferrocene as a probe enables the development of a three-way sensor probe for NO. Furthermore, the triple mode NO detection (electrochemical, colorimetric, and fluorogenic) with ferrocene aids in processing sensing data in a controlled manner similar to Boolean logic operations. This work presents key findings on the mechanism of fluorescence quenching between ferrocene hyponitrite intermediate and PEI-CDs, the potential of using ferrocene for triple channel NO detection as a single molecular entity, and the application of logic gates for NO sensing.

Hemin as a Molecular Probe for Nitric Oxide Detection in Physiological Solutions: Experimental and Theoretical Assessment.

Given its pivotal role in modulating various pathological processes, precise measurement of nitric oxide (●NO) levels in physiological solutions is imperative. The key techniques include the ozone-based chemiluminescence (CL) reactions, amperometric ●NO sensing, and Griess assay, each with its advantages and drawbacks. In this study, a hemin/H2O2/luminol CL reaction was employed for accurately detecting ●NO in diverse solutions. We investigated how the luminescence kinetics was influenced by ●NO from two donors, nitrite and peroxynitrite, while also assessing the impact of culture medium components and reactive species quenchers. Furthermore, we experimentally and theoretically explored the mechanism of hemin oxidation responsible for the initiation of light generation. Although both hemin and ●NO enhanced the H2O2/luminol-based luminescence reactions with distinct kinetics, hemin's interference with ●NO/peroxynitrite- modulated their individual effects. Leveraging the propagated signal due to hemin, the ●NO levels in solution were estimated, observing parallel changes to those detected via amperometric detection in response to varying concentrations of the ●NO-donor. The examined reactions aid in comprehending the mechanism of ●NO/hemin/H2O2/luminol interactions and how these can be used for detecting ●NO in solution with minimal sample size demands. Moreover, the selectivity across different solutions can be improved by incorporating certain quenchers for reactive species into the reaction.

Turn-On Fluorescence Probe for Nitric Oxide Detection and Bioimaging in Live Cells and Zebrafish.

An effective bioanalytical method for rapid, sensitive, specific, and in situ sensing of nitric oxide (NO) is the key for further unveiling the biological functions of this gasotransmitter molecule in vitro and in vivo. In this contribution, a new fluorescence probe for sensing and imaging of NO in live systems was developed. The probe, FP-NO, was designed by exploring a novel sensing mechanism, i.e., the rotation of the N-N single bond of a coumarin derivative. FP-NO was prepared by incorporating a recognition unit, thiosemicarbazide moiety into a coumarin fluorophore. The weakly fluorescent FP-NO quickly and selectively reacts with NO to form a highly fluorescent product, FP-P. Such an enhancement of fluorescence emission allows NO detection with high sensitivity. The detection limit was 47.6 nM. The reaction mechanism was validated by HRMS titration analysis and the "OFF-ON" fluorescence response mechanism was rationalized by theoretical computation. FP-NO is biocompatible and live cell membrane permeable. The feasibility of FP-NO as the fluorescence probe for imaging and flow cytometry analysis of exogenous NO in MCF-7 cells and exogenous NO production in inflamed J774A.1 macrophage cells was then evaluated. Visualization of exogenous and endogenous NO production in live zebrafish was then achieved, implying the potential application of FP-NO in the studies of the NO roles in live organisms.

Bovine serum albumin template synthesis of fluorescent gold nanoclusters for nitric oxide detection in vitro

Bovine serum albumin (BSA) stabilised gold nanoclusters (Au NCs) were prepared and used for nitric oxide (NO) detection in vitro. The prepared BSA-Au NCs with an average diameter of 1.5 nm emitted strong red photoluminescence (PL), accompanied with the maximum emission peak at 640 nm. Furthermore, the BSA-Au NCs were developed as a PL probe for NO detection in vitro. Owing to the damage of BSA-Au NCs structure caused by the interaction between NO and BSA, the PL intensity of BSA-Au NCs regularly reduced with the increase in NO concentration [NO]. There is a proportional relationship between the PL intensity of BSA-Au NCs and the [NO] (0.05–0.35 mM), together with a detection limit of 0.017 mM. Experimental results confirmed high selectivity and sensitivity of the NO probe over other reactive oxygen and nitrogen species, and presented excellent detection capacity in aqueous model samples.

A Novel Protocol for Detection of Nitric Oxide in Plants.

Detection of nitric oxide (NO) in plant cells is mostly undertaken using diaminofluorescein (DAF) dyes. Serious drawbacks and limitations have been identified in methods using DAF as a probe for NO detection. The present work reporting an alternative fluorescent probe for NO detection is thus proposed for varied applications in plant systems for physiological investigations. This method involves a simple, two-step synthesis, characterization, and application of MNIP-Cu {Copper derivative of [4-methoxy-2-(1H-napthol[2,3-d]imidazol-2-yl)phenol]} for specific and rapid binding with NO, leading to its detection in plant cells by epifluorescence microscopy and confocal laser scanning microscopy (CLSM). Using sunflower (Helianthus annuus L.) whole seedlings, hypocotyl segments, stigmas from capitulum, protoplasts, and isolated oil bodies, present investigations demonstrate the versatile nature of MNIP-Cu in applications for NO localization studies. MNIP-Cu can detect NO in vivo without any time lag (ex. 330-385 nm; em. 420-500 nm). It exhibits fluorescence both under anoxic and oxygen-rich conditions. This probe is specific to NO, which enhances its fluorescence due to MNIP-Cu complexing with NO and treatment with PTIO leads to quenching of fluorescence. It is relatively nontoxic when used at a concentration of up to 50 μM.

A Highly Selective Low-Background Fluorescent Imaging Agent for Nitric Oxide

We introduce a novel sensing mechanism for nitric oxide (NO) detection with a particular easily synthesized embodiment (NO(550)), which displays a rapid and linear response to NO with a red-shifted 1500-fold turn-on signal from a dark background. Excellent selectivity was observed against other reactive oxygen/nitrogen species, pH, and various substances that interfere with existing probes. NO(550) crosses cell membranes but not nuclear membranes and is suitable for both intra- and extracellular NO quantifications. Good cytocompatibility was found during in vitro studies with two different cell lines. The high specificity, dark background, facile synthesis, and low pH dependence make NO(550) a superior probe for NO detection when used as an imaging agent.

Development of a Ruthenium(II) Complex Based Luminescent Probe for Imaging Nitric Oxide Production in Living Cells

A unique ruthenium(II) complex, bis(2,2'-bipyridine)(4-(3,4-diaminophenoxy)-2,2'-bipyridine)ruthenium(II) hexafluorophosphate ([(Ru(bpy)(2)(dabpy)][PF(6)](2)), has been designed and synthesized as a highly sensitive and selective luminescence probe for the imaging of nitric oxide (NO) production in living cells. The complex can specifically react with NO in aqueous buffers under aerobic conditions to yield its triazole derivative with a high reaction rate constant at the 10(10) M(-1) s(-1) level; this reaction is accompanied by a remarkable increase of the luminescence quantum yield from 0.13 to 2.2 %. Compared with organic probes, the new Ru(II) complex probe shows the advantages of a large Stokes shift (>150 nm), water solubility, and a wide pH-availability range (pH independent at pH>5). In addition, it was found that the new probe could be easily transferred into both living animal cells and plant cells by the coincubation method, whereas the triazole derivative was cell-membrane impermeable. The probe was successfully used for luminescence-imaging detection of the exogenous NO in mouse macrophage cells and endogenous NO in gardenia cells. The results demonstrated the efficacy and advantages of the new probe for NO detection in living cells.

Development of a novel fluorescent probe for nitric oxide detection: 8-(3′,4′-diaminophenyl)-difluoroboradiaza- S-indacence

A novel fluorescent probe, 8-(3′,4′-diaminophenyl)-difluoroboradiaza- S-indacence (DABODIPY), was designed and synthesized for monitoring nitric oxide production, which features high photostability and no pH dependency over a wide pH range. The fluorescence of 8-(3′,4′-diaminophenyl)-difluoroboradiaza- S-indacence is very low, however, when the probe traps nitric oxide (NO) in the presence of dioxygen, the strong fluorescent triazole form is obtained, which offers the advantages of specificity, and sensitivity for direct detection of NO. Calibration using various concentrations of NO showed the method has good linearity (0.08–4.00 μmol l −1) and its detection limit is 10 nmol l −1 ( s/ n=3). The proposed method has been used to monitor the release of NO from S-nitrosocysteine, a NO-releasing agent.

Development of a fluorescent probe for nitric oxide detection based on difluoroboradiaza- s-indacene fluorophore

Nitric oxide (NO) is an important mediator involved in various physiological phenomena. To obtain direct evidence for NO functions in vivo, a novel fluorescent probe for NO, 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza- s-indacence (TMDABODIPY) was designed and synthesized, which features high photostability and no pH dependency over a wide pH range. The fluorescence of 1,3,5,7-tetramethyl-8-(3′,4′-diaminophenyl)-difluoroboradiaza- s-indacence is very strong, however, when the reagent traps NO in the presence of dioxygen, the weakly fluorescent triazole form is obtained, which offers the advantages of specificity and sensitivity for direct detection of NO. Calibration for NO showed the response has good linearity (0.01–0.4 μmol l −1) and its detection limit is 2.5 nmol l −1 ( s/ n=3). The proposed method has been used to monitor the release of NO from S-nitrosocysteine, a NO-releasing agent.