Selective Detection Of Nitric Oxide Research Articles

Highly dispersed Ag nanocrystals functionalized ZIF-8 derived ZnO hollow structures for superior sensitive and selective detection of nitric oxide

Nitric oxide (NO) is known as a typical air pollutant and can be extremely hazardous to humans and animals. The pursuit of highly efficient and selective sensing materials for NO detection is still an enormous challenge due to the technical hurdles. In this study, ZIF-8 derived ZnO hollow nanostructures loaded with dispersed Ag nanocrystals (NCs) were synthesized for the first time using a simple solution method. These nanostructures exhibit an excellent NO sensing performance at an operating temperature of 125 °C. The highest response value (66.6, 100 ppm), shortest response time (10 s), and best NO selectivity and stability were achieved when the loading amount of Ag NCs was 0.05 mL. Further experiments demonstrated that the electronic and chemical sensitization effect of the Ag NCs and the unique porous structure of ZIF-8 derived ZnO were mainly responsible for the improved sensing capability. These results indicate that the ZnO hollow nanostructures loaded with Ag NCs are promising sensing materials for NO detection, and this study presents an effective model for the modification of MOS-based gas sensing materials.

Development of a novel C-dots conductometric sensor for NO sensing

Carbon dots (CDs, C-dots) obtained from waste produced during the production of olive oil in Calabria (Italy) have been investigated as a gas sensing material for the sensitive and selective detection of nitric oxide (NO) in air. The obtained CDs were characterized by XPS, FT-IR and ATR-FTIR. CDs were deposited to yield a sensitive layer on a conductometric platform and tested for gas sensing, showing promising characteristics for the selective monitoring of NO in air. The response of CDs composite to NO was 1.5 @ 1250 ppm and the response and recovery times amounted to 90 and 200 s, respectively. The sensing behavior of C-dots prepared using olive waste from a different geographic location (Puglia, Italy) was also reported and compared. It has been found that the sensing behavior of the two different materials based sensors investigated towards nitrogen oxides (NO and NO2) was completely different. On the one hand, the former exhibited selectivity towards NO. On the other, the latter showed prominent selectivity towards NO2. This behavior can be ascribed to the different functional groups exposed on the C-dots surface undergoing non-covalent interactions with a marked specificity of the hydroxyl and ethers moieties for NO and NO2, respectively.

An oPD-CD doped zirconium-based metal–organic frame composite fluorescence probe for efficient and selective detection of nitric oxide

A novel composite fluorescence probe (oPD-CDs@UiO-66-NH2) was successfully prepared for NO detection in the aqueous phase, where carbon quantum dots with NO recognition units were doped in a hydrothermally stable metal–organic framework material.

Efficient nitric oxide sensing on nanostructured La2MMnO6 (M: Co, Cu, Zn) electrodes

Selective detection of nitric oxide (NO) is a challenge for automotive exhaust monitoring systems due to the instability of sensing architectures operating under extreme environments. Herein, yttria-stabilized zirconia (YSZ) solid-electrolyte-based electrochemical gas sensor was developed using double perovskite electrodes (DPO) for selective detection of NO. The La2MMnO6 (M: Co, Cu, Zn) phases were synthesized by sol-gel processing of constituent salts and characterized for physicochemical and sensing properties to investigate the impact of transition metal cations present in octahedral environments on charge transport properties. The La2ZnMnO6 with a predominant Zn2+–Mn4+ charge ordering excelled in the sensing characteristics with high sensitivity (33 mV/decade for 3–80 ppm NO concentration), fast response/recovery time (52/42 s) and significant NO selectivity at 500 °C. The sensing behavior of double perovskites was comprehensively explored and found to abide by the mixed-potential model. Moreover, stable sensing properties over a period of three weeks indicate the here-described sensors to be potentially competitive for onboard exhaust monitoring in automobiles.

An N-nitrosation reaction-based fluorescent probe for detecting nitric oxide in living cells and inflammatory zebrafish

Nitric oxide (NO), an essential biological messenger molecule, participates in various physiological and pathological processes. The sensitive and specific detection of NO is of great significance for understanding the biological function of NO. Here, we synthesized a fluorescent probe (Rho-NO) for highly selective detection of NO both in vitro and in vivo. The high selectivity of Rho-NO is attributed to the fact that NO is easily replaced by electron donor amino group to form N-nitrosation products, causing rhodamine spiro ring open and fluorescence emit. Rho-NO showed a good linear response to NO (0–100 µM) with a low detection limit (0.06 µM). Importantly, it exhibited excellent specificity for NO detection in human serum and was also applied for imaging NO in living cells and inflammatory model of zebrafish. This work proves the potential of Rho-NO in pathological research and disease diagnosis.

Biomass-derived hierarchical porous ZnO microtubules for highly selective detection of ppb-level nitric oxide at low temperature

• Porous ZnO hierarchical structure was simply prepared by using hemp fiber as biotemplate. • Hemp fiber template plays a vital role in regulating microstructure and performance of ZnO-600. • The ZnO-600 sensor exhibits fast response, high sensitivity and selectivity to trace NO at 92 °C. • The detection limit of 5 ppb NO for ZnO-600 material is the lowest in reported ZnO-based sensors. Highly sensitive and selective detection of nitric oxide (NO) has recently attracted much attention due to its environmental pollution and biological role. Herein, hierarchical porous ZnO microtubules were simply and massively prepared through zinc salt immersion and air calcination using hemp fiber as biotemplate. The effect of different calcination temperature on the microstructure and gas-sensing performance was investigated. The ZnO-600 microtubules calcined at 600 °C are assembled from the cross-linking nanoparticles with good crystallinity. Especially, the multi-pores and diverse nano-channels are in favor of the quick diffusion and adsorption of target gas, enabling ZnO-600 material to present excellent gas-sensing performance towards trace NO. At low working temperature of 92 °C, the sensor fabricated by ZnO-600 microtubules to NO exhibits high response (10 ppm, S = 78.54), fast response-recovery, good selectivity as well as satisfactory stability and anti-humidity. Meanwhile, this sensor represents the lowest detection limit of 5 ppb (S = 1.22) among all reported ZnO-based sensors. Moreover, the gas-sensing mechanism for ZnO-600 material is demonstrated to be surface adsorption control model.

Selective and Sensocompatible Electrochemical Nitric Oxide Sensor with a Bilaminar Design.

Macrophages mediate mammalian inflammation in part by the release of the gasotransmitter, nitric oxide (NO). Electrochemical methods represent the best means of direct, continuous measurement of NO, but monitoring continuous release from immunostimulated macrophages remains analytically challenging. Long release durations necessitate consistent sensor performance (i.e., sensitivity and selectivity for NO) in proteinaceous media. Herein, we describe the fabrication of an electrochemical sensor modified by an electropolymerized 5-amino-1-naphthol (poly(5A1N)) film in conjunction with a fluorinated xerogel topcoat. The unique combination of these membranes ensures selective detection of NO that is maintained over extended periods of use (>24 h) in biological media without performance deterioration. The hydrophobic xerogel topcoat protects the underlying NO-selective poly(5A1N) film from hydration-induced desorption. The bilaminar sensor is then readily adapted for measurement of the temporal NO-release profiles from immunostimulated macrophages.

A rhodamine-deoxylactam based fluorescent probe for fast and selective detection of nitric oxide in living cells

Nitric oxide (NO) plays vital roles in many physiological process and is closely related to many diseases. So far, a number of fluorescent probes have been constructed for the detection of NO successfully. However, the probes still suffer from long-time reaction and limited selectivity. Herein, a fluorescent probe named dRB-OPD is synthesized and used to recognize NO. The probe contains a deoxy-rhodamine B as fluorophore and o-phenylenediamino as reaction site. dRB-OPD shows fast response to NO within 40 s with 170-fold fluorescence enhancement. Moreover, the probe shows high selectivity towards NO over dehydroascorbic acid (DHA), ascorbic acid (AA), and methylglyoxal (MGO). Particularly, the probe can avoid the serious interference from cysteine (Cys) found in the rhodamine lactam-based fluorescent NO probes (RB-OPD). In addition, the probe is applied for the detection of exogenous and endogenous NO in the HepG2 and RAW 264.7 cells with satisfactory results.

BODIPY-based hydrazine as a fluorescent probe for sensitive and selective detection of nitric oxide: a new strategy

A novel fluorescent probe 8-HB was developed with a BODIPY as a fluorophore and 8-substituted hydrazine as a reactive site for sensitive and selective detection of nitric oxide (NO), generating major fluorescent dehydrazinated BODIPY and minor non-fluorescent azide BODIPY.

Development of a flow microsensor for selective detection of nitric oxide in the presence of hydrogen peroxide

The detection of reactive oxygen and nitrogen species is of utmost importance in several pathological situations. Indeed, these reactive species are biomarkers of oxidative stress and their real-time monitoring is crucial to adapt medical treatments. We report here on the electrochemical detection of nitric oxide (NO) in the presence of hydrogen peroxide (H2O2). The detection was performed by using different sensing microdevices involving either static solutions in wells or flowing solutions in microfluidic channels. Furthermore, an original strategy was proposed to further enhance the selectivity of NO detection at Pt/poly(eugenol) modified platinum electrodes by designing a dual-electrode microfluidic device based on a pre-electrolysis of interfering species including H2O2 at an upstream electrode prior to NO detection.

Roles of catalytic PtO2 nanoparticles on nitric oxide sensing mechanisms of flame-made SnO2 nanoparticles

In this work, PtO2-loaded SnO2 nanoparticles containing 0–2 wt% Pt produced in a single step by flame spray pyrolysis (FSP) technique were systematically evaluated for nitric oxide (NO) detection. Characterizations by various X-ray/electron microscopic and spectroscopic analyses confirmed the formation of PtO2 nanoparticles dispersed on SnO2 surfaces. The sensing films were fabricated by spin-coating and the gas sensing performances were studied towards NO at the operating temperatures ranging from 25 to 350 °C in dry air. It was found that the optimal Pt concentration of 0.2 wt% led to the highest sensor response of 2640 toward 5 ppm NO at the optimal operating temperature of 150 °C, which was about five times higher than that of unloaded one. In addition, the response rate analysis revealed the highest catalytic activity of PtO2 towards NO at 0.2 wt% Pt. Moreover, the PtO2-loaded SnO2 sensor offered improved NO selectivity against NO2, NH3, H2S, C2H5OH and H2. Therefore, the incorporation of PtO2 to SnO2 nanoparticles by FSP is a promising mean to achieve responsive and selective detection of NO and can be useful for various environmental and biomedical applications.

Highly Sensitive Amperometric Sensor Based on Gold Nanoparticles Polyaniline Electrochemically Reduced Graphene Oxide Nanocomposite for Detection of Nitric Oxide

A sensitive electrochemical sensor was fabricated for selective detection of nitric oxide (NO) based on electrochemically reduced graphene (ErGO)-polyaniline (PANI)-gold nanoparticles (AuNPs) nanocomposite. It was coated on a gold (Au) electrode through stepwise electrodeposition to form AuNPs-PANI-ErGO/Au electrode. The AuNPs-PANI-rGO nanocomposite was characterized by Field Emission Scanning Electron Microscopy (FESEM) and UV-vis. Electrochemical behavior of modified electrode was analyzed by cyclic voltammetry (CV) and chronoamperometry (CA) techniques. CVs of AuNPs-PANI-ErGO/Au, PANI-ErGO/Au and ErGO/Au electrodes showed that conductivity of AuNPs-PANI-ErGO/Au was higher than others. Nafion was used to improve selectivity of modified electrode. Nafion/AuNPs-PANI-ErGO/Au electrode represented favorable electrochemical and electrocatalytic behavior towards NO oxidation. The resultant electrode exhibited a high sensitivity of 0.113 μA/μM over a wide linear range from 0.8 × 10−6 to 86 × 10−6 M with a low detection limit of 2.5 × 10−7 M (S/N=3). In addition, the sensor had excellent stability, as well as reproducibility and selectivity, which makes it possible to detect NO quickly and accurately.

A thienyl-pyridine-based Hantzsch ester fluorescent probe for the selective detection of nitric oxide and its bio-imaging applications

A thienyl-pyridine-based Hantzsch ester fluorescent probe for the selective detection of nitric oxide and its bio-imaging applications

Detection of Nitric Oxide from Living Cells Using Polymeric Zinc Organic Framework-Derived Zinc Oxide Composite with Conducting Polymer.

Sensitive and selective detection of nitric oxide (NO) in the human body is crucial since it has the vital roles in the physiological and pathological processes. This study reports a new type of electrochemical NO biosensor based on zinc-dithiooxamide framework derived porous ZnO nanoparticles and polyterthiophene-rGO composite. By taking advantage of the synergetic effect between ZnO and poly(TTBA-rGO) (TTBA = 3'-(p-benzoic acid)-2,2':5',2″-terthiophene, rGO = reduced graphene oxide) nanocomposite layer, the poly(TTBA-rGO)/ZnO sensor probe displays excellent electrocatalytic activity and explores to detect NO released from normal and cancer cell lines. The ZnO is immobilized on a composite layer of poly(TTBA-rGO). The highly porous ZnO offers a high electrolyte accessible surface area and high ion-electron transport rates that efficiently catalyze the NO reduction reaction. Amperometry with the modified electrode displays highly sensitive response and wide dynamic range of 0.019-76 × 10-6 m with the detection limit of 7.7 ± 0.43 × 10-9 m. The sensor probe is demonstrated to detect NO released from living cells by drug stimulation. The proposed sensor provides a powerful platform for the low detection limit that is feasible for real-time analysis of NO in a biological system.

A simple functional carbon nanotube fiber for in vivo monitoring of NO in a rat brain following cerebral ischemia.

Nitric oxide (NO) is key free-radical messenger and neuronal signal which is closely related to many brain diseases. It is a challenge to develop a sensitive and reliable biosensor for in vivo monitoring of NO in the brain. In this research, a simple ratiometric electrochemical biosensor for NO monitoring in rat brain following cerebral ischemia was developed using a carbon nanotube fiber (CNF) modified with hemin, in which the CNF not only served as a platform to assemble the hemin molecule, but greatly facilitated the electron transfer of hemin on to the electrode surface. Additionally, the hemin molecule was found to play dual roles: as a stable catalyst for the reduction of NO for selective detection of NO at -0.67 V versus silver/silver chloride, as well as an inner reference element to provide a built-in correction, to avoid the interference from the complicated brain environment. The developed ratiometric biosensor can detect NO with a linear range from 25 to 1000 nM, with a low limit of detection down to 10 nM, which fulfills the requirements for in vivo measurement of NO. The remarkable analytical performance of the present biosensor, as well as the long-term stability and good reproducibility established this as a reliable approach for in vivo monitoring of NO in the hippocampus of rat brains following cerebral ischemia. This is the first report that the average level of NO increased from 61 ± 23 nM to 141 ± 18 nM after cerebral ischemia for 15 min.

Sonochemical and sustainable synthesis of graphene-gold (G-Au) nanocomposites for enzymeless and selective electrochemical detection of nitric oxide

In this study, a sonochemical approach was utilised for the development of graphene-gold (G-Au) nanocomposite. Through the sonochemical method, simultaneous exfoliation of graphite and the reduction of gold chloride occurs to produce highly crystalline G-Au nanocomposite. The in situ growth of gold nanoparticles (AuNPs) took place on the surface of exfoliated few-layer graphene sheets. The G-Au nanocomposite was characterised by UV–vis, XRD, FTIR, TEM, XPS and Raman spectroscopy techniques. This G-Au nanocomposite was used to modify glassy carbon electrode (GCE) to fabricate an electrochemical sensor for the selective detection of nitric oxide (NO), a critical cancer biomarker. G-Au modified GCE exhibited an enhanced electrocatalytic response towards the oxidation of NO as compared to other control electrodes. The electrochemical detection of NO was investigated by linear sweep voltammetry analysis, utilising the G-Au modified GCE in a linear range of 10–5000μM which exhibited a limit of detection of 0.04μM (S/N=3).Furthermore, this enzyme-free G-Au/GCE exhibited an excellent selectivity towards NO in the presence of interferences. The synergistic effect of graphene and AuNPs, which facilitated exceptional electron-transfer processes between the electrolyte and the GCE thereby improving the sensing performance of the fabricated G-Au modified electrode with stable and reproducible responses. This G-Au nanocomposite introduces a new electrode material in the sensitive and selective detection of NO, a prominent biomarker of cancer.

An Approach for the Selective Detection of Nitric Oxide in Biological Systems: An in vitro and in vivo Perspective.

A naphthalimide-based fluorescent probe, LyNP-NO, was designed and synthesized for the selective detection of exogenously and endogenously generated nitric oxide (NO) in C6 glial cells. In addition, LyNP-NO was also explored for monitoring endogenous NO levels in rat hippocampus at various tissue depths by stimulating the brain with N-methyl-d-aspartate (NMDA).

Fluorescence turn-on for the highly selective detection of nitric oxide in vitro and in living cells.

Nitric oxide (NO) is the first ubiquitous signaling molecule in the human body. The selective and sensitive detection of NO in vitro and in vivo is of high importance but remains challenging. Previous fluorescent probes for NO detection either are of poor water solubility or lack selectivity over intracellular biomolecules. Herein, we rationally designed a water-soluble, biocompatible, small molecular probe o-phenylenediamine-Phe-Phe-OH (1) for the highly selective and sensitive detection of NO in vitro and in living cells. 1 can react with NO and turn on the fluorescence emission at 367 nm via an ICT mechanism. In vitro tests indicated that 1 showed high selectivity for NO detection without interference from common anions, ROS/RNS, and intracellular biomolecules DHA, AA, or MGO. In PBS buffer, 1 was applied for detecting NO within the range of 0-12 μM with a LOD of 6 nM. Moreover, 1 was successfully applied to sense intracellularly generated NO in living cells. We anticipate that 1 could be potentially employed for studying the toxicity and bioactivity of NO in the near future.

Building Selectivity for NO Sensing in a NOx Mixture with Sonochemically Prepared CuO Structures

Several technologies are available for decreasing nitrogen oxide (NOx) emissions from combustion sources, including selective catalytic reduction methods. In this process, ammonia reacts with nitric oxide (NO) and nitrogen dioxide (NO2). As the stoichiometry of the two reactions is different, electrochemical sensor systems that can distinguish between NO and NO2 in a mixture of these two gases are of interest. Since NO and NO2 can be brought to equilibrium, depending on the temperature and the surfaces that they are in contact with, the detection of NO and NO2 independently is a difficult problem and has not been solved to date. In this study, we explore a high surface area sonochemically prepared CuO as the resistive sensing medium. CuO is a poor catalyst for NOx equilibration, and requires temperatures of 500 C to bring about equilibration. Thus, at 300 C, NO and NO2 retain their levels after interaction with CuO surface. In addition, NO adsorbs more strongly on the CuO over NO2. Using these two concepts, we can detect NO with minimal interference from NO2, if the latter gas concentration does not exceed 20% in a NOx mixture over a range of 100–800 ppm. Since this range constitutes most of the range of total NOx concentrations in diesel and other lean burn engines, this sensor should find application in selective detection of NO in this combustion application. A limitation of this sensor is the interference with CO, but with combustion in excess air, this problem should be alleviated.

Hyperbranched polyether hybrid nanospheres with CdSe quantum dots incorporated for selective detection of nitric oxide

In this work, hybrid nanosphere vehicles consisting of cadmium selenide quantum dots (CdSe QDs) were synthesized for nitric oxide (NO) donating and real-time detecting. The nanospheres with QDs being encapsulation have spherical outline with dimension of ~127nm. The fluorescence properties of the mHP conjugated QDs are sensitivity and high selectivity for NO against oxidation products from NO. The QDs-mHP-NO nanospheres provide perspectives for designing a new class of biocompatible NO donating and imaging systems.