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Electrochemical determination of antioxidant capacities in flavored waters by guanine and adenine biosensors
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Orientador(es)
Resumo(s)
The immobilization and electro-oxidation of guanine and adenine asDNA bases on glassy carbon electrode
are evaluated by square wave voltammetric analysis. The influence of electrochemical pretreatments,
nature of supporting electrolyte, pH, accumulation time and composition of DNA nucleotides on the
immobilization effect and the electrochemical mechanism are discussed. Trace levels of either guanine
or adenine can be readily detected following short accumulation time with detection limits of 35 and
40 ngmL−1 for guanine and adenine, respectively.
The biosensors of guanine and adenine were employed for the voltammetric detection of antioxidant
capacity in flavored water samples. The method relies on monitoring the changes of the intrinsic anodic
response of the surface-confined guanine and adenine species, resulting from its interaction with free
radicals from Fenton-type reaction in absence and presence of antioxidant. Ascorbic acid was used as
standard to evaluate antioxidant capacities of samples. Analytical data was compared with that of FRAP
method.
Descrição
Palavras-chave
Guanine Adenine Voltammetry Flavored waters Antioxidant capacity
Contexto Educativo
Citação
Editora
Elsevier