Amphiphilic boronic acid (BA)-substituted block copolymers have been utilized in biomedical applications through binding to saccharides, including to glucose whereas binding to the anaerobically produced metabolite lactate is unreported. Glucose requires basic conditions, while lactate binding occurs at neutral physiological conditions. Herein, BA binding to glucose and lactate is used for the first time to convert solvated hydrophobic homopolymer and hydrophobic block copolymers to amphiphilic core-shell nanoparticle spheres and worms.