A Bipartite Expression for the Transient Amperometric Current at a Membrane Covered Planar Electrode to Characterize Solute Diffusion Through the Membrane
✍ Scribed by Zimei Rong; Sarah Rashid; Pankaj Vadgama
- Publisher
- John Wiley and Sons
- Year
- 2006
- Tongue
- English
- Weight
- 120 KB
- Volume
- 18
- Category
- Article
- ISSN
- 1040-0397
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✦ Synopsis
Abstract
A simple bipartite expression for transient amperometric currents at a membrane covered planar electrode has been derived. This expression is uniquely applicable across the entire measurement time frame and enables a rapid, comprehensive dynamic simulation of solute diffusion through the membrane barrier. The effective diffusion coefficient through the membrane for an electrochemically active solute can be readily obtained by employing the simple curve fitting routine. The diffusion coefficients for 4‐acetaminophenol through 0.05 and 0.025 μm pore diameter mixed cellulose esters membranes were determined to be 1.96×10^−7^ and 1.21×10^−7^ cm^2^/s, respectively. For catechol respective values were 1.55×10^−7^ and 1.15×10^−7^ cm^2^/s. Diffusion coefficients were reduced following membrane exposure to bovine serum albumin and this change provided a functional counterpart to conventional structural measures of surface biofouling. The approach has relevance to both sensors and membrane separation systems in biomedicine, and has the potential to offer a rapid assessment of membrane surface biofouling.