Selective Detection Of Glutathione Research Articles

Photophysical Study of Heteroatom-Doped Carbon Dots-MnO2-Based Nanosensor: Selective Detection of Glutathione in the Nanomolar Level.

Heteroatom doping on carbon dots (Cdots) has been developed as an efficient approach to modify its optical and electronic properties. The four different types of heteroatom-doped Cdots (undoped Cdots (u-Cdots, nitrogen-doped Cdots (N-Cdots), sulfur-doped Cdots (Cdots), nitrogen, sulfur codoped Cdots (N, S-Cdots)) have been synthesized through a simple heat treatment of 5 min. Among four different heteroatoms doped nanosensors, N, S-Cdots with MnO2 nanospheres (Mn NS) showed one of the best fluorescents "on-off-on" nanosensors for selective sensing of glutathione (GSH) and cell imaging. N, S-Cdots showed a high fluorescence quantum yield, good photostability, ionic strength, and pH stability. N, S-Cdots with Mn NS demonstrated extremely high fluorescence quenching efficiency and the maximum fluorescence recovery rate after adding GSH to the produced solution. The photophysical study of N, S-Cdots-Mn NS used as a sensor confirms the inner filter effect (IFE) quenching mechanism between them. The developed sensor has an 80 nM limit of detection (LOD) for GSH. The heteroatom-doped framework of Cdots plays a significant role in the sensitive detection of GSH. N, S-Cdots-Mn NS have good permeability, biocompatibility, and low toxicity, due to which it was used in the intracellular imaging of GSH in living cells. The prepared sensor is rapid, economical, less toxic, and highly applicable in diagnosing diseases.

Facile fabrication of a superior electrochemical sensor with anti-fouling properties for sensitive and selective determination of glutathione

A novel electrochemical sensor was proposed for sensitive and selective detection of glutathione (GSH). The as-fabricated sensor composed of chitosan (Chit), polyethylene glycol (PEG-OH), porous magnesium metasilicate (PMMS), and silver nanoparticles (AgNPs). Chit and PEG were used as anti-fouling nanomaterials, while PMMS acted as a porous adsorbent that loads large amounts of Cu(II). AgNPs increased the conductivity and the electro-catalytic activity of nanocomposite; besides, it enhanced the adsorption of GSH. Based on the electro-catalytic ability of Cu(II) released from Cu(II)-PMMS, the platform could achieve sensitive and selective determination of GSH without the addition of free Cu(II) in the measured solution. Under optimal conditions, a characteristic peak of GSH-Cu(II) was observed at ca. 0.43 V, which was increased linearly with GSH concentration in the range 0.1 to 125 µM with a detection limit (LOD, S/N = 3) of 0.03 µM. The sensor exhibited excellent sensitivity, anti-fouling performance, good selectivity, and sufficient stability. More importantly, the sensor was successfully applied for the estimation of GSH in dietary supplements and human plasma serum samples with acceptable recoveries % (98.3–104.1%) and RSDs values not more than 3.2%. These results proved that the as-fabricated sensor can be used for monitoring of GSH during medical diagnosis.

Ultrasensitive and Selective Detection of Glutathione by Ammonium Carbamate-Gold Platinum Nanoparticles-Based Electrochemical Sensor.

Determining the concentration of glutathione is crucial for developing workable medical diagnostic strategies. In this paper, we developed an electrochemical sensor by electrodepositing amino-based reactive groups and gold–platinum nanomaterials on the surface of glassy carbon electrode successively. The sensor was characterized by cyclic voltammetry (CV), field emission scanning electron microscope (FESEM), energy dispersive X-ray spectroscopy (EDX), and electrochemical impedance spectra (EIS). Results showed that Au@Pt nanoparticles with the size of 20–40 nm were presented on the surface of electrode. The sensor exhibits excellent electrocatalytic oxidation towards glutathione. Based on this, we devised an electrochemical biosensor for rapid and sensitive detection of glutathione. After optimizing experimental and operational conditions, a linear response for the concentration of GSH, in the range of 0.1–11 μmol/L, with low detection and quantification limits of 0.051 μM (S/N = 3), were obtained. The sensor also exhibits superior selectivity, reproducibility, low cost, as well as simple preparation and can be applied in human serum sample detection.

The Mn-modified porphyrin metal-organic framework with enhanced oxidase-like activity for sensitively colorimetric detection of glutathione

The selective detection of glutathione (GSH) has been used as important colorimetric probe for human health. Herein, we used a facile method to synthesize manganese ions modified porphyrin metal-organic framework (PCN-224-Mn) with a size of 125.7 ± 14.2 nm and zeta potential of −3.9 ± 0.5 mV. We showed that PCN-224-Mn catalyzed oxidation of 3,3′,5,5′-tetramethylbenzidine (TMB) in the absence of H2O2, resulting in a blue-colored oxidized TMB (oxTMB) that exhibits oxidase-like activity. Furthermore, a simple colorimetric detection method for GSH was developed based on the oxidase-like activity of PCN-224-Mn. This method shows wide linear detection range of 0.5–60 μM for GSH with a much lower detection limit of 0.233 μM. Finally, the recovery of colorimetric sensor of PCN-224-Mn suggests its great potential as a biosensor. As the catalytically active site, the manganese porphyrin unit plays a major role in the oxidase-like property and detection ability of PCN-224-Mn. Our data suggest that GSH detection method using PCN-224-Mn has great potential in multiple applications in the future.

Fabrication of polyethyleneimine surface-functionalized fluorescent carbon dots and its applications towards highly sensitive and selective detection of glutathione in aqueous medium and in vitro cell imaging of HeLa cells

Fabrication of polyethyleneimine surface-functionalized fluorescent carbon dots and its applications towards highly sensitive and selective detection of glutathione in aqueous medium and in vitro cell imaging of HeLa cells

Selective detection of glutathione by flower-like NiV2O6 with only peroxidase-like activity at neutral pH

In view of the broad application prospect of peroxidase-like nanozymes in biomedical analysis, it is of great significance to eliminate the interference of their oxidase-like activity and enable them to work under neutral conditions. Herein, flower-like NiV2O6 was synthesized and their enzyme-mimicking activity was investigated. Through the regulation of pH, NiV2O6 nanozyme showed only peroxidase-like activity but not oxidase-like activity under neutral conditions, which could catalyze the oxidation of colorless 3,3′,5,5′-tetramethylbenzidine into its blue product in the presence of H2O2. Furthermore, based on the competitive effect of glutathione (GSH) on the catalytic activity of nanozymes, a semi-quantitative/quantitative colorimetric assay was established for GSH detection by using peroxidase-like NiV2O6. The assay exhibited a good linear relationship in GSH concentration ranging from 3–100 μmol L−1, with a detection limit of 0.89 μmol L−1. Moreover, in the presence of formaldehyde as masking agent, this method showed satisfactory specificity for GSH under the interference of a variety of interfering substances and even biothiols. Concerning the practical application, the system was applied to monitor GSH level in fetal bovine serum, human serum and SiHa cells. Satisfyingly, the obtained results were consistent well with those of Ultra performance liquid chromatography (UPLC) and assay kit, indicating the constructed assay has great potential in clinical application.

Rapid synthesis of fluorescent bovine serum albumin-gold nanoclusters complex for glutathione determination.

A facile one-pot method for synthesis of bovine serum albumin (BSA)-gold nanoclusters (AuNCs) has been developed. The formation of BSA-AuNCs took only 30s under mild conditions. BSA-AuNCs exhibited strong orange-yellow fluorescence, and the excitation and emission peaks were at 370nm and 564nm, respectively. In the process of forming BSA-AuNCs, the molecular chain of BSA has not been destroyed. Moreover, there were a large number of Au cations on the surface of BSA-AuNCs, which had strong oxidizing abilities. The reason for the ultrabright fluorescence of BSA-AuNCs was attributed to the Au(0)@Au(I)@Au(III)-ligand structure on the surface of BSA. In order to evaluate the fluorescence performance of BSA-AuNCs, BSA-AuNCs was used as a probe, realizing the sensitive and selective determination of glutathione (GSH) in a wide linear range of 0.01-0.48μM and a detection limit of 3.3nM. The proposed method not only offers a brand-new scheme for synthesizing BSA-AuNCs, but also provides a platform for studying the interaction between metal core and proteins. A facile one-pot method to synthesize ultrabright fluorescent BSA-AuNCs in tens of seconds has been introduced by mixing BSA suspension, KSCN, and HAuCl4. The as-prepared BSA-AuNCs showed intensive orange-yellow fluorescence under a UV lamp (365nm), and BSA still keeps the integral molecular chains during the whole synthesis process. Moreover, the as-prepared BSA-AuNCs have realized the sensitive and selective detection of glutathione (GSH) in a wide linear range of 0.01-0.48μM and a detection limit of 3.3nM.

Highly Sensitive and Selective Detection of Glutathione Using Ultrasonic Aided Synthesis of Novel Graphene Quantum Dots Embedded Over Amine-Funtionalized Silica Nanoparticles

Highly Sensitive and Selective Detection of Glutathione Using Ultrasonic Aided Synthesis of Novel Graphene Quantum Dots Embedded Over Amine-Funtionalized Silica Nanoparticles

Facile synthesis of AgNPs@SNCDs nanocomposites as a fluorescent 'turn on' sensor for detection of glutathione.

The present study illustrates the facile synthesis of silver nanoparticles capped with sulfur and nitrogen co-doped carbon dots (AgNPs@SNCDs) nanocomposites and their application towards the sensitive and selective detection of glutathione (GSH) using a spectrofluorimetry method. SNCDs were synthesized using solvothermal treatment of cysteamine hydrochloride and p-phenylenediamine. The as-fabricated SNCDs were then utilized as capping and stabilizing agents for the preparation of AgNPs@SNCDs nanocomposites using wet chemistry. The size of AgNPs@SNCDs nanocomposites was characterized to be ~37.58 nm or even larger aggregates. Particularly, the quenched fluorescence of AgNPs@SNCDs nanocomposites could be significantly restored upon addition of GSH, and the colour of its solution changed to some extent. The fluorescence intensity ratio of AgNPs@SNCDs nanocomposites at ~450 nm and 550 nm was directly proportional to the GSH concentration within the ranges 8.35-66.83 μM and 66.83-200.5 μM, and the detection limit was 0.52 μM. Furthermore various common organic molecules had no obvious interference in the detection mode. The proposed nanosensor was successfully applied for GSH assay in actual water samples.

A core-shell MWCNT@rGONR heterostructure modified glassy carbon electrode for ultrasensitive electrochemical detection of glutathione

In this work, a multiwalled carbon nanotubes@reduced graphene oxide nanoribbons core-shell heterostructure (MWCNT@rGONR)-modified glassy carbon electrode (MWCNT@rGONR/GCE) was employed to electrochemically detect glutathione (GSH). The morphologies and microstructures of the as-prepared MWCNT@rGONR heterostructure were examined by field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and Fourier transform infrared spectroscopy spectrum (FT-IR), respectively. The electrochemical characteristics and catalytic behaviors of the fabricated sensor for determination of GSH were systematically investigated by cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), differential pulse voltammetry (DPV), and amperometry (i–t). Under optimum conditions, the MWCNT@rGONR heterostructure modified electrode possesses the ability of strong electrocatalytic for GSH with high selectivity and sensitivity, fast response, wide linear range, low detection limit (39 nM) and outstanding reproducibility. Its further application for the quantification of GSH concentration in human serum samples was also demonstrated with satisfactory accuracy. These features indicate that the prepared core-shell MWCNT@rGONR heterostructure with unique electronic structure offers an excellent biosensing platform for sensitive and selective detection of glutathione.

A novel near-infrared styryl-BODIPY fluorescent probe for discrimination of GSH and its application in living cells

A novel near-infrared (NIR) fluorescent probe BODIPY-ONs for sensitive and selective detection of glutathione (GSH) was reported. The probe carried with 2,4-dinitrobenzenesulfonyl group (DNBS) as quenching group was non-fluorescent. Upon addition of glutathione, an obvious NIR fluorescence recovery centered at 656 nm was observed and the quantum yield increased to 0.48, while other thiol-lacking amino acids did not generate any change. Compared with Cys and Hcy, BODIPY-ONs showed the highest response toward GSH. The limit of detection (LOD) for GSH was calculated as 131 nM from the titration experiments. The cleavage of the suphonate induced by GSH was proposed, which was supported by Mass spectral analysis and HPLC analysis. Further theoretical calculation indicated that an intermolecular hydrogen bond assited thiolysis process was the reason that BODIPY-ONs can discriminate GSH from Cys and Hcy. Moreover, probe BODIPY-ONs could also be used for endogenous and exogenous GSH detection in living cells.

Rhodamine-based fluorescent probes for selective detection of glutathione and cysteine

Small-molecule thiols such as cysteine (Cys) and glutathione (GSH) are essential for maintaining the cellular redox environment and play important roles in regulating various cellular functions. Therefore, it is significant to quantitatively detect the small-molecule thiols in clinical chemistry and biochemistry. Here, we synthesized a new probe RT by using a rhodol-based fluorescent dye with long emission wavelength (λ em = 635 nm) as the fluorophore and the DNBS group as the response unit. It was found that the probe RT showed high response speed and selectivity toward Cys and GSH over other amino acids. After reacting with Cys/GSH, it shows a strong red fluorescence, corresponding to a color change from colorless to purple, which can be easily discriminated by the naked eye. The detection limit of the probe RT is as low as 24 nM to Cys and 20 nM to GSH. All these advantages of the probe RT make it possible for the quantitative detection of small-molecule thiols such as Cys and GSH in living organisms.

Single-layer MnO2 nanosheets for sensitive and selective detection of glutathione by a colorimetric method

The rapid, sensitive and selective detection of glutathione (GSH) is of great importance in the biological systems. In this work, a template-free and one-step method was used to synthesize the single-layer MnO2 nanosheets via a redox reaction. The resulting product was characterized by XRD, TEM, FTIR, XPS and UV–vis absorption. The addition of GSH results in the change of solution color depth owing to the occurrence of a redox reaction between MnO2 and GSH, enabling colorimetric detection of GSH. At a pH of 3.6, the proposed sensor gives a linear calibration over a GSH concentration range of 10–100μM, with a rapid response of less than 2min and a low detection limit of 0.5μM. The relative standard deviation for seven repeated determinations of GSH is lower than 5.6%. Furthermore, the chemical response of the synthesized MnO2 nanosheets toward GSH is selective. Owing to the advantages with good water solubility, rapid response, high sensitivity, good biocompatibility and operation simplicity, this two-dimensional MnO2-based sensing material might be potential for detecting GSH in biological applications.

Near-Infrared Fluorescent Probe with High Quantum Yield and Its Application in the Selective Detection of Glutathione in Living Cells and Tissues.

Glutathione (GSH), cysteine (Cys), and homocysteine (Hcy) are small-molecular biothiols that play key roles in various biological systems. Among these biothiols, GSH is the most abundant intracellular thiol. Until now, a small number of the near-infrared (NIR) fluorescent probes have been designed for the detection of GSH. Unfortunately, most of these NIR probes are based on cyanine dyes, which generally suffer low fluorescence quantum yield (Φ < 0.25), which are not suitable for bioimaging. In addition, some probes are difficult to effectively distinguish GSH from Cys and Hcy. In this work, an NIR fluorescent probe with high fluorescence quantum yield is developed by introducing a rigid coplanar structure such as rhodamine dyes, and the NIR probe (CyR) with spirolactam structure is first synthesized and used to recognize GSH. The characteristics of this NIR probe are as follows: (1) probe CyR exhibits high fluorescence quantum yield (Φ = 0.43) after the addition of GSH and high sensitivity toward GSH with 75-fold fluorescence enhancement. (2) The probe is highly selective, which will not interfere with the other biological thiols (Cys, Hcy) and amino acids. (3) A possible reaction mechanism of the NIR probe CyR and GSH (Cys, Hcy) can be proposed and proved by 1H NMR, 13C NMR, and MS (mass spectra). (4) The NIR probe displays selective detection of GSH in biological samples such as living cells and tissues.

Electrochemical detection of glutathione by using thymine-rich DNA-gated switch functionalized mesoporous silica nanoparticles

A novel electrochemical sensor for highly sensitive and selective detection of glutathione (GSH) was developed coupled thymine-Hg2+-thymine (T-Hg2+-T) coordination with mesoporous silica nanoparticles (MSN). Hg2+ ions could specifically interact with thymine bases to form strong and stable T-Hg2+-T complexes. And the electroactive molecules-methylene blue (MB) was sealed in the inner pores of MSN with a unique sequential thymine (T)-rich DNA in the presence of Hg2+. After the target was added, the formed duplex DNA T-Hg2+-T complex could deform into single-stranded DNA by a competitive displacement reaction, leading to the release of MB entrapped in the MSN. Thus the target-dependent amount of released MB could be conveniently monitored with an n-dodecanethiol modified screen-printed gold electrode. Using GSH as a model target, the proposed assay showed a wide detection ranging from 1.0nM to 1.0μM with a detection limit of 0.6nM. This strategy was simple and universal for various analytes with different competitive displacement ligands, possessing a great potential for convenient biotools testing and commercial application.

A dopamine-modulated nitrogen-doped graphene quantum dot fluorescence sensor for the detection of glutathione in biological samples

A dopamine-modulated nitrogen-doped graphene quantum dot (N-GQD) system was explored to develop a fluorescent sensor based on a chemical redox mechanism for the facile, sensitive and selective detection of glutathione (GSH) in biological samples.

Synthesis of a new highly sensitive near-infrared fluorescent iridium(iii) probe and its application for the highly selective detection of glutathione

A new near-IR fluorescent probe (probe 1) based on the IR 780 skeleton exhibits high selectivity and sensitivity towards Ir(iii) in an EtOH/H2O solution. The probe 1–Ir(iii) complex was also used for the highly selective detection of glutathione.

Intracellular Glutathione Detection Using MnO2-Nanosheet-Modified Upconversion Nanoparticles

We report a novel design, based on a combination of lanthanide-doped upconversion nanoparticles and manganese dioxide nanosheets, for rapid, selective detection of glutathione in aqueous solutions and living cells. In this approach, manganese dioxide (MnO(2)) nanosheets formed on the surface of nanoparticles serve as an efficient quencher for upconverted luminescence. The luminescence can be turned on by introducing glutathione that reduces MnO(2) into Mn(2+). The ability to monitor the glutathione concentration intracellularly may enable rational design of a convenient platform for targeted drug and gene delivery.