RESUMO
Given its pivotal role in modulating various pathological processes, precise measurement of nitric oxide (âNO) levels in physiological solutions is imperative. The key techniques include the ozone-based chemiluminescence (CL) reactions, amperometric âNO sensing, and Griess assay, each with its advantages and drawbacks. In this study, a hemin/H2O2/luminol CL reaction was employed for accurately detecting âNO in diverse solutions. We investigated how the luminescence kinetics was influenced by âNO 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 âNO enhanced the H2O2/luminol-based luminescence reactions with distinct kinetics, hemin's interference with âNO/peroxynitrite- modulated their individual effects. Leveraging the propagated signal due to hemin, the âNO levels in solution were estimated, observing parallel changes to those detected via amperometric detection in response to varying concentrations of the âNO-donor. The examined reactions aid in comprehending the mechanism of âNO/hemin/H2O2/luminol interactions and how these can be used for detecting âNO 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.
Assuntos
Hemina , Sondas Moleculares , Óxido Nítrico , Hemina/química , Peróxido de Hidrogênio/química , Peróxido de Hidrogênio/análise , Cinética , Medições Luminescentes , Luminol/química , Sondas Moleculares/química , Óxido Nítrico/análise , Oxirredução , Ácido Peroxinitroso/análise , Ácido Peroxinitroso/química , SoluçõesRESUMO
Peroxynitrite (ONOO-) is a potent bio-oxidant involved in many physiological and pathological processes; however, most of the pathological effects associated with ONOO-in vivo are still ambiguous. Herein, we designed and synthesized two near-infrared ratiometric fluorescent probes, Ratio-A and Ratio-B, for the detection and biological evaluation of ONOO-. The recognition unit diene in the probes could be specifically cleaved by ONOO- with a 94-fold enhancement in the ratiometric fluorescence signal. By imaging ONOO- in immune stimulated cells and acute inflammation mice model using Ratio-A, we investigated the fluctuations of ONOO- levels in a rheumatoid arthritis (RA) model of mice. Ratio-A could be applied for the effective imaging of RA and could rapidly evaluate the response of the RA treatment with methotrexate (MTX). Thus, Ratio-A can be considered as a promising tool for pathological diagnosis and the therapeutic assessment of a wide range of diseases including RA.