Detection Of Intracellular Hydrogen Peroxide Research Articles

AIE-ESIPT Photoluminescent Probe Based on 3-(3-Hydroxypyridin-2-yl)isoquinolin-4-ol for the Detection of Intracellular Hydrogen Peroxide.

Excited-state intramolecular proton transfer (ESIPT) molecules, which feature large Stokes shifts to avoid self-absorption, play an essential role in photoluminescent bioimaging probes. Herein, we report the development of an ESIPT molecule 3-(3-hydroxypyridin-2-yl)isoquinolin-4-ol (PiQ).PiQnot only undergoes a distinct ESIPT process unlike the symmetrical 2,2'-bipyridyl-3,3'-diol but also exhibits aggregation-induced emission (AIE)characteristics. PiQself-assembles into aggregates with an average size of 241.0 ± 51.9 nm in aqueous solutions, leading to significantly enhanced photoluminescence. On the basis of the ESIPT and AIE characteristics ofPiQ, the latter is functionalized with a hydrogen peroxide-responsive 4-pinacoratoborylbenzyl group (B) and a carboxylesterase-responsive acetyl group (A) to produce a photoluminescent probeB-PiQ-A. The potential ofPiQfor applications in bioimaging and chemical sensing is underscored by its efficient detection of both endogenous and exogenous hydrogen peroxide in living cells.

Enhanced on-Chip modification and intracellular hydrogen peroxide detection via gigahertz acoustic streaming microfluidic platform

Developing effective strategies for the flexible control of fluid is vital for microfluidic electrochemical biosensing. In this study, a gigahertz (GHz) acoustic streaming (AS) based sonoelectrochemical system was developed to realize an on-chip surface modification and sensitive hydrogen peroxide (H2O2) detection from living cells. The flexible and controlled fluid surrounding the electrochemical chip was optimized theoretically and applied in the sonoelectrochemical deposition of Au nanoparticles (AuNPs) first. Under the steady and fast flow stimulus of AS, AuNPs could be synthesized with a smaller and evener size distribution than the normal condition, allowing AuNPs to show an excellent peroxidase-like activity. Moreover, the AS also accelerated the mass transport of target molecules and improved the catalytic rate, leading to the enhancement of H2O2 detection, with an extremely low detection limit of 32 nM and a high sensitivity of 4.34 μA/ (mM·mm2). Finally, this system was successfully applied in tracking H2O2 release from different cell lines to distinguish the cancer cells from normal cells. This study innovatively integrated the surface modification and molecules detection process on a chip, and also proposed a simple but sensitive platform for microfluidic biosensing application.

SERS and dark-field scattering dual-mode detection of intracellular hydrogen peroxide using biocompatible Au@COF nanosensor

Hydrogen peroxide is widely involved in intracellular physiological activities, playing vital roles in regulating various intracellular metabolite and physiological events. Surface-enhanced Raman scattering (SERS) may serve as a promising technique to efficiently sensing metabolites in living cells owing to its non-invasiveness, low autofluorescence, and rapid detection capability. Herein, a size-controllable core-shell structure was constructed by covering 2D covalent organic frameworks (COFs) on Au nanoparticles (Au@COF), and the cellular hydrogen peroxide were detected by Raman spectroscopy/Dark-field scattering imaging dual-mode technique. The introduction of COFs endows Au@COF with perfect enrichment capacity as well as high stability and good biocompatibility. Combining the superior fingerprint identification of SERS and the imaging capability of dark-field microscopy, the present method exhibits high applicability for hydrogen peroxide detection in living cells. Results show that when the living MCF-7 cells were treated by different drugs, the level of hydrogen peroxide metabolite can be monitored in real-time. This study provides a simple but sensitive and facile platform for biosensing hydrogen peroxide and cellular metabolites.

Bovine serum albumin decorated gold nanoclusters: A fluorescence-based nanoprobe for detection of intracellular hydrogen peroxide

Gold nanoclusters are well studied due to their facile synthesis, biocompatibility, limited photobleaching, and bright fluorescence properties. Monitoring the reactive oxygen species (ROS) level in mammalian cells is required to assess the healthy metabolism of oxygen, cell signaling, and homeostasis. ROS are also known to cause several human diseases including cancer, neurodegenerative disease, diabetes, and cardiovascular disorders, therefore, following the ROS status could provide important information about the critical pathophysiology of the diseased cells/tissues. Among different ROS, hydrogen peroxide is a well-reported stable oxidative stress biomarker for several diseases. In this work, we report the synthesis of BSA coated AuNCs (BSA-AuNCs) displaying bright red fluorescence (Ex./Em. 511/651 nm), which utilized for the degradation of hydrogen peroxide with concomitant loss of fluorescence of BSA-AuNCs. The fluorescence property of this nanoprobe was used for the detection of hydrogen peroxide levels in liver cells (WRL-68). The accumulation of hydrogen peroxide in WRL-68 cells was artificially induced by 3-amino-1,2,4-triazole (catalase inhibitor) treatment, which leads to a decrease in the fluorescence intensity of BSA-AuNCs to enable fluorescence-based sensing of hydrogen peroxide. Thus, the synthesized fluorescent BSA-AuNCs could be used for the detection of intracellular hydrogen peroxide.

A novel enzymatic biosensor for detection of intracellular hydrogen peroxide based on 1-aminopyrene and reduced graphene oxides

An electrochemical sensor for hydrogen peroxide $$(\text {H}_{2}\text {O}_{2})$$ detection was established using 1-aminopyrene (AP) as a linker between horseradish peroxidase (HRP) and reduced graphene oxides (rGO) modified glassy carbon electrode. The AP can combine with HRP via a covalent bond and combine with rGO via $$\uppi $$ - $$\uppi $$ conjugation. The covalent bond linkages can prevent the enzymes leaching of the enzymes and the $$\uppi $$ - $$\uppi $$ conjugate combination can facilitate electrons transfer, which plays synergistic effects to improve the performance of this sensor. The electrochemical activity of the HRP-AP/rGO was described by cyclic voltammetry, alternating current impedance and amperometric techniques. Under the optimal conditions, the biosensor showed a wide linear range from 1.5 $$\upmu $$ M to 28.5 $$\upmu $$ M and a low detection limit of 0.5 $$\upmu $$ M with good stability and high selectivity, confirming that the sensor is well-suited for the detection of $$\text {H}_{2}\text {O}_{2}$$ during biological processes. Using 1-aminopyrene (AP) as a linker between horseradish peroxidase (HRP) and reduced graphene oxides (rGO), an enzymatic hydrogen peroxide ( $$\text {H}_{2}\text {O}_{2})$$ biosensor was established with wide linear range, good stability and high selectivity.

Direct reduction of HAuCl4 for the visual detection of intracellular hydrogen peroxide based on Au-Pt/SiO2 nanospheres

It is attractive but remains challenging to develop nanomaterials-based methods to realize the colorimetric detection of ultratrace biological analytes. In this work, an HAuCl4-H2O2 system was developed for the visual detection of intracellular hydrogen peroxide (H2O2) based on the Au-Pt/SiO2 sensing platform. Owing to their excellent intrinsic peroxidase-like activity, Au-Pt/SiO2 nanospheres were introduced to catalyze the decomposition of H2O2 and then directly reduce HAuCl4 into gold nanoparticles (Au NPs) for the naked-eye detection. The produced Au NPs behaved color variations from light purple to wine red as H2O2 concentration increased. Under the optimal conditions, this strategy showed excellent sensitivity for H2O2 with a detection limit of 0.1nM by naked-eye readout and 0.1 pM by UV–vis spectrometer (S/N=3), as well as acceptable selectivity for H2O2, which could meet the demand for the detection of H2O2 in biological systems. The method was further validated by the determination of H2O2 in HeLa cells with low cellular cytotoxicity. Thus, this strategy would provide simple and sensitive detection of H2O2 in biological systems, revealing the potential application in clinical, biological and environmental researches.

Intracellular Hydrogen Peroxide Detection with Functionalised Nanoelectrodes

AbstractHydrogen peroxide (H2O2) is one of the most important reactive oxygen species, and it is involved in a number of cellular processes ranging from signal transduction to immune defence and oxidative stress. It is of great interest to intracellularly quantify H2O2 to improve the understanding of its role in disease processes. In this study, we present an amperometric nanosensor for the quantification of H2O2 at the single‐cell level. Deposition of the electrocatalyst Prussian Blue on carbon nanoelectrodes enables selective H2O2 reduction at mild potentials. Owing to their small size and needle‐type shape, these nanoelectrodes can penetrate the membrane of single living cells, causing only minimal perturbation. The nanosensors allow for the monitoring of penetration‐induced oxidative outbursts as well as the uptake of H2O2 from the extracellular environment in single murine macrophages.

A 3,7-Dihydroxyphenoxazine-based Fluorescent Probe for Selective Detection of Intracellular Hydrogen Peroxide.

A novel N-borylbenzyloxycarbonyl-3,7-dihydroxyphenoxazine fluorescent probe (NBCD) for detecting H2O2 in living cells is described. The probe could achieve high selectivity for detecting H2O2 over other biological reactive oxygen species (ROS). In addition, upon addition of H2O2, NBCD exhibited color change from colorless to pink, which makes it a "naked-eye" probe for H2O2 detection. NBCD could not only be used to detect enzymatically generated H2O2 but also to detect H2O2 in living systems by using fluorescence spectroscopy, with a detection limit of 2 μm. Importantly, NBCD enabled the visualization of epidermal growth factor (EGF)-stimulated H2O2 generation inside the cells.

Mesoporous Pt Nanotubes as a Novel Sensing Platform for Sensitive Detection of Intracellular Hydrogen Peroxide.

Controlling the shape, structure, and surface morphology of nanomaterials is of great significance in optimizing sensitivity and catalytic performances in biosensing applications. The main goal of employing Pt-based nanomaterials is to increase their utilization efficiency due to their high cost. Herein, we report the synthesis of mesoporous Pt nanotubes using Pluronic P123 as soft templates and Ag nanowires with 50 nm in diameter as hard templates. The resultant materials with unique structures show high sensitivity and stability toward H2O2 detection with low cellular cytotoxicity. The high sensitivity and catalytic properties are attributed to the mesopores and hollow structures making the inner Pt surfaces accessible to reaction media and enlarging the total surface area and one-dimensional structure facilitating the mass diffusion rate.

Fast temporal detection of intracellular hydrogen peroxide by HyPer

Fast temporal detection of intracellular hydrogen peroxide by HyPer

Enhancement of Radiation-induced Apoptosis by 6-Formylpterin

Radiation-induced apoptosis and its possible enhancement in the presence of 6-formylpterin (6-FP), a metabolite of folic acid, were examined in human myelomonocytic lymphoma U937 cells. When cells were treated with 6-FP at a nontoxic concentration of 300 μM, and then exposed to X-rays at a dose of 10 Gy, significant enhancement of radiation-induced apoptosis as determined by nuclear morphological change, phosphatidylserine (PS) externalization and DNA fragmentation were observed. Flow cytometry for the detection of intracellular hydrogen peroxide (H2O2) revealed that 6-FP increased the formation of intracellular H2O2, which further increased when the cells were irradiated. Decrease of mitochondria trans-membrane potential (MMP), release of cytochrome c from mitochondria, and activation of caspase-3 were enhanced after the combined treatment. Remarkable activation of protein kinase C δ (PKC δ) and its translocation from cytosol to mitochondria were detected in combined treatment. Increase of intracellular Ca2+ concentrations ([Ca2+]i) was also observed, however, neither calpain I nor calpain II could inhibit the apoptosis. In addition, c-Jun NH2-terminal kinase ( JNK) activation was not enhanced in the combined treatment. A protein involved in a caspase-independent apoptosis pathway, apoptosis inducing factor (AIF), remained unchanged even 3 h after treatment. These results indicate that intracellular H2O2 generated by 6-FP enhances radiation-induced apoptosis via the mitochondria-mediated caspase-dependent pathway, with the active involvement of PKC δ.