DNA-functionalized electrochemical biosensor for detection of vitamin B1 using electrochemically treated multiwalled carbon nanotube paste electrode by voltammetric methods

A simple methodology was used to develop a novel electrochemical biosensor for the determination of vitamin B1. The interaction of vitamin B1 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 B1 was used as an indicator signals for the sensitive determination of vitamin B1. Under the optimum conditions, a linear dependence of the guanine and adenine oxidation signals was observed for the vitamin B1 concentration in the range of 1.0–80 μg mL−1 with a detection limit of 0.44 μg mL−1 at ds-DNA modified PMWCNTPE. The reproducibility and applicability of the analysis to serum, plasma and urine sample were also investigated. Vitamin B1 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 B1 concentration over the range of 0.0025–0.80 μg mL−1, with a detection limit of 1.1 ng mL−1 Vitamin B1. Both ds-DNA-modified MWCNPTE and PMWCNTPE were applied to analyze Vitamin B1 in real samples.