The potentiodynamic polymerization of pyrrole is carried out on Pt electrodes using sodium dodecyl sulphate and the coated electrode is employed for sensing of urea non-enzymatically. Employing amperometric and impedimetric methods, urea is estimated in mildly acidic conditions. A detection limit of 40 μM is obtained along with a linearity of 80-1440 μM and a sensitivity of 1.11 μA μM-1 cm-2 from the amperometric data. The Nyquist plot is employed for the construction of the calibration curve from the impedance analysis. The interference of different compounds such as ascorbic acid, uric acid, sodium chloride and calcium chloride is also analyzed. © 2012 Elsevier B.V.

M. V. Sangaranarayanan

Department Of Chemistry

Acidic conditions

AMPEROMETRIC

Amperometry

ASCORBIC ACIDS

Calibration curves

COATED ELECTRODES

Detection limits

Impedance analysis

NON-ENZYMATIC

Nyquist plots

Platinum electrodes

Potentiodynamics

Pt electrode

Sodium dodecyl sulphate

URIC ACIDS

calcium chloride

COATED WIRE ELECTRODES

Cyclic voltammetry

Electrochemical impedance spectroscopy

Electrodes

metabolism

Organic acids

Platinum

Polypyrroles

Sodium

Sodium chloride

urea

IIT Madras is a public technical and research university located in Chennai, Tamil Nadu. Founded in 1959, it is recognised as an Institute of National Importance.

IIT Madras has been ranked as the top engineering institute in India for four years in a row by the National Institutional Ranking Framework of the MHRD

It currently offers undergraduate, postgraduate and research degrees across 16 disciplines in Engineering, Sciences, Humanities and Management. About 596 faculty belonging to science and engineering departments and centres of the Institute are engaged in teaching, research and industrial consultancy.

IIT Madras

Sensors and Actuators, B: Chemical

Silver dendritic structures have been prepared using constant potential deposition on indium tin oxide (ITO) electrodes from an aqueous solution of AgNO3 and KNO3 without any surfactants or structure directing agents. The applied potential is shown to be a crucial factor in the formation of dendrites. Depending upon the magnitude of the applied potentials, morphologies vary from polygons to dendrites. The shape evolution of the silver dendrites has been investigated by varying the deposition time and metal precursors. The mechanism of formation of dendrites is interpreted using the diffusion limited aggregation (DLA) model. The fractal dimensions of the dendrites calculated using the box counting algorithm are in agreement with those predicted by the DLA model. The Ag dendrites coated ITO electrodes exhibit excellent electrocatalytic activity toward oxidation of hydrazine in alkaline medium. The sensing of hydrazine is carried out with amperometry, where from the limit of detection and linear calibration range is deduced as 0.5 μM and 100-1700 μM respectively. The effect of ascorbic acid, urea, ethanol, glucose, K+, Cl-, Br- and I- ions as possible interfering agents in the detection of hydrazine is analyzed. © 2015 Elsevier B.V. All rights reserved.

A facile formation of silver dendrites on indium tin oxide surfaces using electrodeposition and amperometric sensing of hydrazine

We report a facile synthesis of polypyrrole spheres with controllable sizes, monomer units and conductivities using sodium nitrite and nitric acid in presence of the anionic surfactant sodium tetradecyl sulfate. The rapid synthesis of polypyrrole spheres was accomplished without employing any explicit oxidizing agents. The characterization of polypyrrole (PPy) is carried out using FTIR, XRD, SEM, TEM and TGA while the molecular weight is estimated from the MALDI TOF analysis. The precise tuning of various physicochemical properties is accomplished by altering the concentrations of sodium nitrite and is attributed to the in situ generation of NO<inf>2</inf>. The size of the PPy spheres varies from 45 nm to 350 nm depending upon the concentration of NaNO<inf>2</inf>. The dynamic light scattering studies provide mechanistic insights into the role of sodium nitrite in altering the pyrrole-incorporated micellar size of the surfactant, leading to different diameters of the PPy spheres. The surfactant-induced solubility of PPy is rationalized with the help of the X-ray diffraction patterns. The solution of PPy in dimethylsulfoxide has a remarkable ability of selectively detecting Cu2+ and Hg2+ among a host of other bimetallic ions, as inferred from colorimetry and UV-Visible absorption spectroscopy. ©2015 Elsevier Ltd. All rights reserved.

European Polymer Journal

A novel, rapid synthetic protocol for controllable sizes, conductivities and monomer units of soluble polypyrrole

The applicability of tin submicroparticles modified glassy carbon electrodes for sensing of nitrite ions is demonstrated. Tin submicroparticles have been electrodeposited on a glassy carbon electrode using constant potential deposition. The detection of nitrite ions is carried out with differential pulse voltammetry, amperometry and electrochemical impedance spectroscopy. The lowest detection limit of 0.5μM with a linear range of 5μM-1000μM is inferred from the differential pulse voltammetry. The interference from different compounds such as urea, glucose and nitrate ions is also analyzed. © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

Electroanalysis

Electrochemical Sensing of Nitrite Ions Using Tin-Submicroparticles Modified Glassy Carbon Electrodes

Журнал структурной химии

Highly nonplanar macrocyclic ring conformation in the crystal structures of Ni(II) and Cu(II) octaphenylporphyrins

Langmuir

Self-Assembled, Nanostructured Polypyrrole Films Grown in a High-Gravity Environment

ACS Nano

Functionalized Multilayered Graphene Platform for Urea Sensor

Chemical Engineering Journal

Acid blue AS doped polypyrrole (PPy/AS) nanomaterials with different morphologies as electrode materials for supercapacitors

Journal of Applied Polymer Science

LiClO4-doped plasticized chitosan as biodegradable polymer gel electrolyte for supercapacitors

A novel non-enzymatic sensor for urea using a polypyrrole-coated platinum electrode

Journal	Sensors and Actuators, B: Chemical
ISSN	09254005
Open Access	No