A Cole‐Cole Dielectric Relaxation Analysis of Albumin and γ‐Globulins for Protein Quantification by Electrical Impedance Spectroscopy

Abstract

Abstract Optimal serum protein concentrations are vital for normal body functioning. Affordable while accurate protein quantification methods with minimum processing requirements are needed for diagnosis of related diseases. The standard automated chemistry analyzer is limited by high installation and maintenance costs. This study proposes the use of electrical impedimetric spectroscopy (EIS) as an alternative to current methods. Its practical applicability was tested using albumin and γ‐globulin or their miscellanea in three different media; water, serum and tissue‐mimicking phantoms at 25 °C. Impedance measurements were taken between frequency f =0.10 MHz to 300 MHz by an impedance analyzer. A Cole‐Cole analysis was used to elucidate the stepwise variations in the dielectric parameters of the protein medium so as to obtain empirical dielectric parameter‐protein concentration relationships and their correlation coefficients R 2 . From the results, linear relationships between parameters and protein concentrations with high correlation coefficients over R 2 =0.90 were observed. Resistance to charge transfer R ct and characteristic frequency f c were significantly altered by changing protein concentrations as compared to bulk solution resistance R s , relaxation time constant τ and shape factor α . The relationships developed would aid in monitoring changes in body fluid protein concentrations by EIS.