Cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide: factorial design and an application as sensor for NADH

Journal of the Brazilian Chemical Society

Andrea A. Hoffmann²  Silvio L. P. Dias²  Edilson V. Benvenutti²  Eder C. Lima²  Flávio A. Pavan²  Jordana R. Rodrigues²  Rodrigo Scotti²  Emerson S. Ribeiro¹  Yoshitaka Gushikem¹ 

[1] ,Universidade Federal do Rio Grande do Sul Instituto de Química Porto Alegre RS ,Brazil

关键词: meldola blue;    toluidine blue;    modified cellulose acetate;    factorial design;    carbon paste electrode;    NaDH;   

DOI  :  10.1590/S0103-50532007000800003

来源: SciELO

【 摘 要 】

The electrochemical properties of meldola blue and toluidine blue cationic dyes immobilized on cellulose acetate surface modified with titanium dioxide were investigated by cyclic voltammetry. The materials synthesized were employed as carbon paste electrodes. The redox mediator properties of the meldola blue and toluidine blue chemically modified electrodes were optimized using a factorial design, consisting of two levels and four factors with two pseudo-central points (n= 20 experiments). The factorial analysis was carried out by searching for better reversibility of the redox process, such as the lowest separation between anodic and cathodic potential peaks and a current ratio near unity. The factors that presented significant effects on the overall optimization of the system to achieve the best conditions of the reversibility of electron transfer were the main factors scan rate and type of electrode (meldola blue or toluidine blue), besides the interaction factors KCl concentration × type of electrode (B×D) and the pH × [KCl] concentration × scan rate (A×B×C) interaction. The best electrochemical reversibility conditions obtained were: using the CA-TiO2-MB electrode, 1.0 mol L-1 KCl as supporting electrolyte, at scan rate of 10.0 mV s-1. Afterwards, the CA-TiO2-MB modified electrode was tested as an amperometric sensor for the determination of NADH, with a detection limit of 0.1 µmol L-1.

【 授权许可】

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