Biosensors & Bioelectronics

Micellar Effects of Cetyl Pyridinium Chloride on Antioxidant Capacity,Voltammetric Response of Serum and Saliva Samples

Abstract

Madla Adami dos Passos, Denise Vaz de Macedo, Rita de Cássia Silva Luz, Lázaro Alessandro Soares Nunes, Lauro Tatsuo Kubota and Armindo Antonio Alves

The production of reactive oxygen species due to increased energy demand during physical exercise can increase the cellular and blood oxidation state. The reducing power of biological samples reflects its antioxidant capacity, largely maintained by Low Molecular Weight Antioxidants (LMWA), which donate electrons to radical species. LMWA include antioxidants such as uric acid, vitamins C and E and lipoic acid, among others. The electroanalytical technique of Differential Pulse Voltammetry (DPV) presents a good methodological alternative to quantify acute and chronic modulations of the antioxidant capacity from biological fluids in response to metabolic adaptations caused by physical exercise. However, when biological samples are analyzed, proteins are an important preanalytical interfering in the technique. The proteins can be adsorbed on the electrode surface during the potential application, resulting in a significant decrease of voltammetric signal. The aim of the present study was to investigate
the applicability of cationic surfactant Cetyl Pyridinium Chloride (CPC) as a micellar system for the improvement of DPV technique for serum and saliva analysis. Forty individuals' samples were analyzed. The obtained data revealed that the use of CPC increased the sensitivity and stability of the voltammetric signal, enabling the application of the method DPV for serum and saliva samples. Our data suggest that the voltammetric signal of samples is influenced mainly by the uric acid concentration.