The reversible boronic acid–diol interaction empowers boronic acid receptors' saccharide binding capacities, rendering them a class of lectin mimetic, termed “boronlectins”. Boronic acids follow lectin functions not just in being able to bind saccharides, but in multivalent saccharide binding that enhances both affinity and selectivity. For almost a decade, efforts have been made to achieve and improve selectivity for given saccharide targets, most notably glucose, by using properly positioned boronic acids, offering multivalent interactions. Incorporation of several boronic acid groups into a covalent framework or non-covalent assembly of boronic acid are two general methods used to create such smart sensors, of which the latter resembles lectin oligomerisation that affords multivalent saccharide-binding architectures. In this review, we discuss supramolecular selective sensing of saccharides by using simple boronic acids in their aggregate forms, after a brief survey of the general aspects of boronic acid-based saccharide sensing.

Dynamic covalent functionality has been acknowledged as a powerful tool for the construction of organised architectures, the reversible nature thermodynamically facilitates self-control and self-correction. The use of boronic acids complexation with diols and their congeners has already shown great promise in realising and developing reversible boron-containing multicomponent systems with dynamic covalent functionality. The structure-directing potential has lead to the development of a variety of self-organisation involving not only macrocycles, cages and capsules, but also porous covalent organic frameworks and polymers. Structure controls as well as remarkable synthesis are highlighted in this feature article.

In this feature article the use of boronic acids to monitor, identify and isolate analytes within physiological, environmental and industrial scenarios is discussed. Boronic acids recognise diol motifs through boronic ester formation and interact with anions generating boronates, as such they have been exploited in sensing and separation protocols for diol appended molecules such as saccharides and anions alike. Therefore robust molecular sensors with the capacity to detect chosen molecules selectively and signal their presence continues to attract substantial attention, and boronic acids have been exploited with some success to monitor the presence of various analytes. Reversible boronic acid-diol interactions have also been exploited in boron affinity chromatography realising new separation domains through the same binding events. Boronic acid diol and anion interactions pertaining to sensing and separation are surveyed.

A water-soluble boronate-based fluorescent probe was evaluated for the detection of peroxynitrite (ONOO⁻) in the presence of a monosaccharide. The enhanced fluorescence of the probe when bound with D-fructose was switched off in the presence of peroxynitrite. In contrast, other reactive oxygen/nitrogen species (ROS/RNS) led to only slight fluorescence decreases due to protection by an internal N–B interaction. The interaction of the probe with D-fructose not only strengthens the fluorescence signal, but also protects the boronic acid from oxidation by other ROS/RNS. Therefore, under conditions generating various ROS/RNS, the boronate-based saccharide complex preferentially reacts with peroxynitrite. The probe was used in cell imaging experiments for the detection of endogenous and exogenous peroxynitrite. The sensor displays good “on–off” responses towards peroxynitrite, both in RAW 264.7 cells and HeLa cells.