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Voltammetric Studies on Chromotrope 2B‐Protein Interaction and Its Analytical Application
Author(s) -
Sun Wei,
Jiao Kui,
Han JunYing,
Xu GuiYun
Publication year - 2006
Publication title -
journal of the chinese chemical society
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.329
H-Index - 45
eISSN - 2192-6549
pISSN - 0009-4536
DOI - 10.1002/jccs.200600151
Subject(s) - chemistry , electrochemistry , bovine serum albumin , human serum albumin , buffer solution , binding constant , supramolecular chemistry , serum albumin , dropping mercury electrode , electrode , reaction rate constant , analytical chemistry (journal) , chromatography , kinetics , binding site , molecule , organic chemistry , biochemistry , physics , quantum mechanics
Abstract In this paper the interaction of chromotrope 2B (Ch2B) with proteins was studied by the electrochemical method. Ch2B is an azo dye and shows irreversible electrochemical responses on the mercury electrode in a pH 3.0 Britton‐Robinson (B‐R) buffer solution. After the addition of human serum albumin (HSA) into the Ch2B solution, an interaction took place, and a supramolecular complex was formed in the mixed solution. The electrochemical parameters of the Ch2B‐HSA interaction system were calculated and compared. The results showed that in the absence and presence of HSA in Ch2B solution, the electrochemical parameters such as the formal potential E 0 , the electrode reaction standard rate constant k s , etc. showed no significant changes, which indicated that an electro‐inactive supramolecular biocomplex was formed. The free concentration of Ch2B in reaction solution was decreased, and this resulted in the decrease of the peak current. The binding constant and the binding ratio were calculated as 7.85 × 10 9 and 1:2, respectively, and the interaction mechanism was discussed. Based on the decrease of the peak current, this new electrochemical method was proposed for the determination of HSA in the concentration range of 2.0˜25.0 mg/L with the linear regression equation as ΔIp′ (nA) = 50.56C (mg/L) — 6.72 (γ = 0.995). This method was further used to determine other different kinds of proteins, such as bovine serum albumin (BSA), oval albumin, etc‥ The new method was successfully applied to detect the content of albumin in healthy human serum samples with the results in good agreement with the traditional Coomassie Brilliant Blue G‐250 spectrophotometric method.