DNA-functionalized electrochemical biosensor for detection of vitamin Bl using electrochemically treated multiwalled carbon nanotube paste electrode by voltammetric methods

摘要

A simple methodology was used to develop a novel electrochemical biosensor for the determination of vitamin Bl. The interaction of vitamin Bl with DNA based on the decreasing of the oxidation signal of guanine and adenine bases was studied electrochemically with a pretreated multiwalled carbon nanotube paste electrode (PMWCNTPE) using differential pulse voltammetry. The decrease in the intensity of the guanine and adenine oxidation signals after interaction with vitamin Bl was used as an indicator signals for the sensitive determination of vitamin Bl. Under the optimum conditions, a linear dependence of the guanine and adenine oxidation signals was observed for the vitamin Bl concentration in the range of 1.0-80μgmL~(-1) with a detection limit of 0.44μgmL~(-1) at ds-DNA modified PMWCNTPE. The reproducibility and applicability of the analysis to serum, plasma and urine sample were also investigated. Vitamin Bl was also determined on a pretreated multiwalled carbon nanotube paste electrode by means of adsorptive stripping differential pulse voltammetry. The peak current was linearly dependent on Vitamin Bl concentration over the range of 0.0025-0.80 μgmL~(-1), with a detection limit of 1.1 ngmL~(-1) Vitamin Bl. Both ds-DNA-modified MWCNPTE and PMWCNTPE were applied to analyze Vitamin Bl in real samples.