Nitrite In Aqueous Media Research Articles

Electrochemical sensing of nitrite in aqueous media with N, P-codoped biocarbon electrode

Electrochemical sensing of nitrite in aqueous media with N, P-codoped biocarbon electrode

MgAl-layered double hydroxide flower arrays grown on carbon paper for efficient electrochemical sensing of nitrite

In this work, MgAl-layered double hydroxide nanosheets arrays in-situ grown on commercial carbon paper (MA-LDH/CP) have been successfully fabricated via a facile one-pot hydrothermal method, which shows a hierarchical flower-like structure. The as-prepared MA-LDH/CP is used as a free-standing electrode for electrochemical detection of nitrite in aqueous media, showing high sensitivity with a low detection limit of 0.03 μM, and good anti-interference to other species. Moreover, it exhibits outstanding electrochemical stability without any deactivation in almost two months. The superior performance of MA-LDH/CP for nitrite determination is attributed to the 3D hierarchical architecture of MA-LDH nanolayers and a large number of exposed surface sites, which facilitate the electron transfer and nitrite adsorption.

Evaluation of novel Griess-reagent candidates for nitrite sensing in aqueous media identified via molecular fingerprint searching.

The Griess reaction is the most often exploited colorimetric method for the quantitative analysis of nitrite in aqueous media. The application of the currently used reagents are associated with limitations (e.g. linear response range). Herein, molecular fingerprint searching on well-known Griess-reagents was used as a tool for the identification of structurally similar, new reagent candidate molecules. Rapid and high-throughput experimental evaluation of the newly identified Griess-reagent candidates revealed that 14 of the 18 tested reagent candidates had equal or superior response displaying broader linear ranges and/or increased response gradient against various nitrite concentrations in aqueous media when compared to the parent compounds at room temperature.

Investigation of the Roles of Plasma Species Generated by Surface Dielectric Barrier Discharge

As an emerging sterilization technology, cold atmospheric plasma offers a dry, non-thermal, rapid process that is minimally damaging to a majority of substrates. However, the mechanisms by which plasma interacts with living cells are poorly understood and the plasma generation apparatuses are complex and resource-intensive. In this study, the roles of reactive oxygen species (ROS), nitric oxide (NO), and charged particles (ions) produced by surface dielectric barrier discharge (SDBD) plasma on prokaryotic (Listeria monocytogenes (Gram-positive)) and eukaryotic (human umbilical vein endothelial cells (HUVEC)) cellular function were evaluated. HUVEC and bacterial oxidative stress responses, the accumulation of nitrite in aqueous media, air ion density, and bacterial inactivation at various distances from SDBD actuators were measured. SDBD actuator designs were also varied in terms of electrode number and length to evaluate the cellular effects of plasma volume and power distribution. NO and ions were found to contribute minimally to the observed cellular effects, whereas ROS were found to cause rapid bacterial inactivation, induce eukaryotic and prokaryotic oxidative stress, and result in rapid oxidation of bovine muscle tissue. The results of this study underscore the dominance of ROS as the major plasma generated species responsible for cellular effects, with ions and RNS having a secondary, complimentary role.

A new selective turn-on fluorogenic dipodal-cobalt(II) ensemble probe for nitrite ion detection and live cell imaging

A new dipodal-triazole-Co2+-ensemble with a ligand containing quinoline moiety was designed and synthesized as a highly sensitive fluorescent sensor for nitrite in aqueous media. Based on in situ-formed Co2+–DTQ (Co2+ chelated dipodal of triazole-quinoline) ensembles having the specific binding affinity for nitrite anions over other anions, this sensory system allows rapid recognition and quantitative detection of nitrite in neutral aqueous media in an ‘off–on’ fashion. To confirm the suitability of DTQ for biological applications, we also employed it for the fluorescence detection of the changes of intracellular NO2- in three different species of cultured cells in the presence of nitrite ions.

A selective fluorogenic sensor for visual detection of nitrite

Determination of nitrite levels is of substantial interest in many applications from monitoring drinking water quality to clinical diagnosis, etc. N-(Rhodamine B)-lactam-o-phenylenediamine (RB-PDA) was identified from a panel of rhodamine-lactams for fluorogenic and visual detection of nitrite in aqueous media via analyte triggered formation of highly fluorescent and deep colored species.