Selective and sensitive electrochemical device for direct VB2 determination in real products

The developed by us electrochemical device for vitamin B2 (VB2; riboflavin) determination, without preconcentration step, in real products exhibits high sensitivity, selectivity, stability and low detection limit compared to those described in the literature. The determination procedure was based on the monitoring of the reduction current signal of VB2 bound with dsDNA anchored to the electrode surface through intermediary – carboxyphenyl layer. The application of such intermediary layer formed during electroreduction of appropriate diazonium salt at CV peak potential guarantees high efficiency of hybridization process and thus fully available places for VB2 interaction. Moreover, such intermediary layer provides good electrical contact, what is very important in the case of electrochemical sensors. The analytical range of work of the proposed VB2 sensor was between 0.08–1 µM (30–377 μg L−1) of riboflavin concentration. The obtained detection (LOD) and quantification limits (LOQ) were 24±2 and 55±5 μg L−1, respectively. The proposed VB2 detection method was used for determination of riboflavin content in commercially available dietary supplements and yolk of hen egg samples. The accuracy of the obtained data was proved using comparison with an independent method (HPLC FLD).