Increased bandwidth for dielectric spectroscopy of proteins through electrode surface preparation.
Dielectric spectroscopy measurements of liquids are often limited by electrode polarization. The influence of surface polishing and deposition of the conducting polymer polypyrrole/polystyrenesulfonate (PPy/PSS) on the polarization impedance is investigated. A quantitative description of the electrode polarization contribution to the real-valued permittivity spectrum is derived. This description explains the origin of the ω(-const). (const.>1) dependency commonly observed in permittivity measurements. Electrode surface roughness is correlated with both the magnitude and phase of the constant phase element. Generally, rougher electrodes have better performance, and an order of magnitude bandwidth improvement is achieved using PPy/PSS electrodes.
Department of Electrical and Computer Engineering, Brigham Young University, Provo, Utah 84602, USA.
Brett L
BL
Mellor
Efrén Cruz
EC
Cortés
Shiul
S
Khadka
Brian A
BA
Mazzeo
D000818:Animals; D002417:Cattle; D058266:Dielectric Spectroscopy / Q000295:instrumentation / Q000379:methods*; D004566:Electrodes; D007782:Lactoglobulins / Q000737:chemistry*; D011108:Polymers / Q000737:chemistry; D011137:Polystyrenes / Q000737:chemistry; D011758:Pyrroles / Q000737:chemistry; D013499:Surface Properties
D007782:Lactoglobulins; D011108:Polymers; D011137:Polystyrenes; D011758:Pyrroles; C067635:polypyrrole; C003321:polystyrene sulfonic acid