Display omitted •Reaction rate of boronic acid with diols is calculated with five different R-groups.•To account for proton tunnelling quantum corrections are added to the reaction rate.•Higher electronegativity results in shortening the proton donor-acceptor distance.•This induces proton tunnelling and increases the reaction rate. Designing an efficient saccharide sensor in aqueous solution is an ongoing endeavour. Even though using hydrogen bonding groups on the sensor sounds like an efficient way for targeting the saccharides, it might lack accuracy due to the possibility of interaction with the solvent molecules. Boronic acid based sensors on the other hand, covalently and reversibly bind to saccharides with high sensitivity in aqueous medium. Many attempts are done to understand the mechanism of boronic acid’s reaction with diols. However, the binding affinity of fructose cannot be clearly identified in such attempts. This study employs a novel computational approach to increase both reactivity and selectivity of boronic acid towards diols. Using DFT, five different electronegative R-groups are simulated to calculate boronic acid’s reactivity towards diol by adding the tunnelling effect to the calculations, where higher electronegative R-groups reduce the proton donor-acceptor distance that induces proton tunnelling and increases the reaction rate.