Simultaneous determination of phenylhydrazine and hydrazine by a nanostructured electrochemical sensor

A colorimetric and fluorometric probe for phenylhydrazine and its application in real samples

A fluorescent probe for phenylhydrazine detection was developed with aldehyde as the recognition group and good selectivity towards phenylhydrazine over hydrazine, hydroxylamine and other amines was observed. Its application in real water samples and fast visualization of phenylhydrazine using a probe-loaded paper strip were demonstrated.

Electrochemical sensor based on polyoxometalate immobilized using a layer-by-layer assembly process to detect 2,4-dinitrophenylhydrazine

An electrochemical sensor for the detection of 2,4-dinitrophenylhydrazine was developed by utilizing the reversible redox properties of W-containing polyoxometalates.

Real time detection and monitoring of 2, 4-dinitrophenylhydrazine in industrial effluents and water bodies by electrochemical approach based on novel conductive polymeric composite

Much attention has been given to detection and monitoring of hydrazine-based compounds in recent time because of its significant negative impacts on human health and ecosystem (aquatic lives). This prompted the current study focusing on detection of 2, 4-dinitrophenylhydrazine (2, 4-dnphz) using electrochemically synthesized poly-para amino benzoic acid-manganese oxide (P-pABA-MnO₂) composite film. The synthesized P-pABA-MnO₂ composite film was characterized in terms of its structural and morphological properties by X-ray diffraction spectroscopy and field emission scanning electron microscopy respectively. In addition, functionalities and binding energy of p-PABA-MnO2 were confirmed using Fourier transform infrared spectroscopy and X-ray photoelectron spectroscopy respectively. Finally, electrochemical properties were investigated using electrochemical impedance spectroscopy and cyclic voltammetry. The synthesized P-pABA-MnO₂ displayed good electrocatalytic reduction property towards 2, 4-dnphz with ultra-low limit of detection (0.08 μM; S/N = 3) and very high sensitivity (52 μAμ^-1Mcm^-2). The proposed sensor based on P-pABA-MnO₂ also demonstrated good stability in terms of repeatability, reproducibility and interferents effects. Lastly, the proposed sensor was satisfactorily used in detection of 2, 4-dnphz in environmental real samples.

Porous palladium-poly(3,4-ethylenedioxythiophene)-coated carbon microspheres/graphene nanoplatelet-modified electrode for flow-based-amperometric hydrazine sensor

A highly stable flow-injection amperometric hydrazine sensor was developed based on a glassy carbon electrode modified with palladium-poly(3,4-ethylene dioxythiophene) coated on carbon microspheres/graphene nanoplatelets (Pd-PEDOT@CM/GNP/GCE). The Pd-PEDOT@CM/GNP composite was characterized by scanning electron microscopy and energy-dispersive x-ray analysis (SEM/EDX). The modified GCE was electrochemically characterized using cyclic voltammetry and chronoamperometry. The electrocatalytic activity of the Pd-PEDOT@CM/GNP/GCE toward hydrazine oxidation was significantly better than the activity of a bare GCE, a CM/GCE, a GNP/GCE, a Pd-PEDOT/GCE, and a Pd-PEDOT@CM/GCE. The sensor operated best at a low working potential of + 0.10 V (vs. Ag/AgCl). Under optimal conditions, sensitivity toward hydrazine detection and operational stability (601 injections/one electrode preparation) were excellent. The response was linear from 1.0 to 100 μmol L^-1 and from 100 to 5000 μmol L^-1 with a detection limit of 0.28 ± 0.02 μmol L^-1 and high sensitivity of 0.200 μA μM^-1 cm^-2. The sensor showed good repeatability (relative standard deviation (RSD) < 1.4%, n = 15), reproducibility (RSD < 2.7%, n = 6), and anti-interference characteristics toward hydrazine detection. The feasibility of the electrochemical sensor was proved by the successful determination of hydrazine in water samples, and the results were in good agreement with those obtained from spectrophotometric analysis. Graphical abstract.

In-Doped ZnO Hexagonal Stepped Nanorods and Nanodisks as Potential Scaffold for Highly-Sensitive Phenyl Hydrazine Chemical Sensors

Herein, we report the growth of In-doped ZnO (IZO) nanomaterials, i.e., stepped hexagonal nanorods and nanodisks by the thermal evaporation process using metallic zinc and indium powders in the presence of oxygen. The as-grown IZO nanomaterials were investigated by several techniques in order to examine their morphological, structural, compositional and optical properties. The detailed investigations confirmed that the grown nanomaterials, i.e., nanorods and nanodisks possess well-crystallinity with wurtzite hexagonal phase and grown in high density. The room-temperature PL spectra exhibited a suppressed UV emissions with strong green emissions for both In-doped ZnO nanomaterials, i.e., nanorods and nanodisks. From an application point of view, the grown IZO nanomaterials were used as a potential scaffold to fabricate sensitive phenyl hydrazine chemical sensors based on the I-V technique. The observed sensitivities of the fabricated sensors based on IZO nanorods and nanodisks were 70.43 μA·mM^-1 cm^-2 and 130.18 μA·mM^-1 cm^-2, respectively. For both the fabricated sensors, the experimental detection limit was 0.5 μM, while the linear range was 0.5 μM-5.0 mM. The observed results revealed that the simply grown IZO nanomaterials could efficiently be used to fabricate highly sensitive chemical sensors.

Copper nanoparticles decorated polyaniline–zeolite nanocomposite for the nanomolar simultaneous detection of hydrazine and phenylhydrazine

The high electrocatalytic activity of the CuNPs–PANI–Nano-ZSM-5 nanocomposite can be attributed to the synergistic contribution provided by the highly dispersed copper nanoparticles and conductive PANI film on high surface area Nano-ZSM-5.

Electrochemical detection of the MT-ND6 gene and its enzymatic digestion: application in human genomic sample

A simple electrochemical biosensor was developed for the detection of the mitochondrial NADH dehydrogenase 6 gene (MT-ND6) and its enzymatic digestion by BamHI enzyme. This biosensor was fabricated by modification of a glassy carbon electrode with gold nanoparticles (AuNPs/GCE) and a probe oligonucleotide (ssDNA/AuNPs/GCE). The probe, which is a thiolated segment of the MT-ND6 gene, was deposited by self-assembling immobilization on AuNPs/GCE. Two indicators including methylene blue (MB) and neutral red (NR) were used as the electroactive indicators and the electrochemical response of the modified electrode was measured by differential pulse voltammetry. The proposed biosensor can detect the complementary sequences of the MT-ND6 gene. Also the modified electrode was used for the detection of an enzymatic digestion process by BamHI enzyme. The electrochemical biosensor can detect the MT-ND6 gene and its enzymatic digestion in polymerase chain reaction (PCR)-amplified DNA extracted from human blood. Also the biosensor was used directly for detection of the MT-ND6 gene in all of the human genome.