Concentration Polarization and the Polarographic Current-Time Curve. I. Rate of the Consecutive Reaction Consisting of the Linear Diffusion Process and the Electrode Reaction

The equation of the A.C. polarographic current for processes where the frequency of the alternating field is comparable with the rate of the electrode reaction is derived. Relative values of equilibrium rate constants of some first order electrode reactions are evaluated experimentally.

Download Full-text

Integrated design of switching control and mobile actuator/sensor guidance for a linear diffusion process

Journal of the Franklin Institute ◽

10.1016/j.jfranklin.2019.06.045 ◽

2019 ◽

Vol 356 (13) ◽

pp. 7246-7262 ◽

Cited By ~ 1

Author(s):

Huai-Ning Wu ◽

Xiao-Wei Zhang

Keyword(s):

Diffusion Process ◽

Integrated Design ◽

Switching Control ◽

Linear Diffusion

Download Full-text

Non-enzymatic sensor for determination of glucose based on PtNi nanoparticles decorated graphene

Scientific Reports ◽

10.1038/s41598-020-73567-2 ◽

2020 ◽

Vol 10 (1) ◽

Author(s):

Risheng Li ◽

Xu Deng ◽

Longfei Xia

Keyword(s):

Limit Of Detection ◽

High Sensitivity ◽

Glucose Detection ◽

Serum Samples ◽

Time Curve ◽

Current Time ◽

Glass Carbon ◽

Graphene Glass ◽

Ptni Alloy

Abstract Diabetes has become a universal epidemic in recent years. Herein, the monitoring of glucose in blood is of importance in clinical applications. In this work, PtNi alloy nanoparticles homogeneously dispersed on graphene (PtNi alloy-graphene) was synthesized as a highly effective electrode material for glucose detection. Based on the modified PtNi alloy-graphene/glass carbon (PtNi alloy-graphene/GC) electrode, it is found that the PtNi alloy-graphene/GC electrode exhibited excellent electrocatalytic performance on glucose oxidation. Furthermore, the results from amperometric current–time curve show a good linear range of 0.5–15 mM with the limit of detection of 16 uM (S/N = 3) and a high sensitivity of 24.03 uAmM−1 cm−2. On account of the good selectivity and durability, the modified electrode was successfully applied on glucose detection in blood serum samples.

Download Full-text

The polarography of beryllium

Australian Journal of Chemistry ◽

10.1071/ch9641072 ◽

1964 ◽

Vol 17 (10) ◽

pp. 1072 ◽

Cited By ~ 1

Author(s):

PJ Shirvington ◽

TM Florence ◽

AJ Harle

Keyword(s):

Aqueous Media ◽

Electrode Reaction ◽

Complexing Agents ◽

Water Molecules ◽

Hydroxyl Groups ◽

Reduction Step ◽

Current Time ◽

Diffusion Controlled ◽

Coordinated Water ◽

Potentiometric Data

The polarography of beryllium in 0.5M lithium chloride has been investigated in some detail, using several polarographic and coulometric techniques. Current-time curves, microscopic examination and cinematography of the mercury drop, and the effect of complexing agents, aided in elucidating the electrode process. The experimental data show that the polarographic step for the tetraquoberyllium ion is diffusion-controlled but irreversible, and results from the reduction of two protons liberated from the coordinated water molecules, yielding beryllium hydroxide and hydrogen. The evidence suggests that this reduction takes place in a stepwise process, with a soluble beryllium hydroxy complex as an intermediate. The polarographic results can be correlated with published potentiometric data on the composition and stabilities of hydrolysed beryllium species in aqueous media. The number of electrons involved in the electrode reaction depends on the number of hydroxyl groups per beryllium atom in the beryllium complex. Beryllium oxalate and salicylate complexes also give a reduction step, but only if the complex contains coordinated water molecules. The diffusion coefficient of the tetraquoberyllium ion was found to be 6.2 � 0.3 x 10-6 cm2 sec-1 at 30�.

Download Full-text