Nanomolar level sensing of glucose in food samples using glucose oxidase confined MWCNT-Inulin-TiO2 bio-nanocomposite

•Sensing trace level of glucose in commercial food products is important.•CP/MWCNT-Inulin-TiO2/GOx, a new kind of electrode was fabricated for sensing glucose.•Nanomolar sensing of glucose in sugar free products was achieved using the electrode.•Study revealed that some of the sugar free products were not 100% glucose free.•Storage stability (150 days) was higher than that of other carbon based electrodes. Development of an effective sensor for sensing glucose in commercially available “sugar free” food products is important as people are becoming diabetic health conscious. Although multi-walled carbon nanotubes (MWCNTs) possess interesting electrical properties, their hydrophobic nature limits their applications. Their hydrophilicity can be improved through modification. In the present study, Inulin, that was isolated from Allium sativum L. using hot water diffusion and incorporated with titanium dioxide (TiO2), was used for the modification of MWCNTs. The as-synthesized MWCNT-Inulin-TiO2 bio-nanocomposite immobilized with glucose oxidase (GOx) was incorporated into the carbon paste matrix and was utilized for the sensing of glucose in food products. Differential pulse voltammetric studies revealed that the fabricated electrode demonstrated good linear range (1.6 nM to 1 μM) and was sensitive to nanomolar concentrations of glucose with a very low limit of detection up to 0.82 nM and exhibited a long term stability of 150 days.