One-pot synthesis of a gold nanoparticle–Vmh2 hydrophobin nanobiocomplex for glucose monitoring

Hydrophobin Vmh2 is a small amphiphilic protein, which self-assembles on different surfaces and naturally interacts with glucose. Here, we report on the synthesis of a nanobiocomplex made of polyethylene glycol, Vmh2 and gold nanoparticles by a one-step process and on its ability to recognise glucose in an aqueous solution at 0.3–0.6–1.2 mg ml−1 concentrations. Even though the Vmh2 proteins are intrinsically bonded to the gold core, effective glucose interaction monitoring was demonstrated by using dynamic light scattering, ultraviolet–visible, polarizationmodulated infrared reflection–absorption and x-ray photoelectron spectroscopies. Experimental results highlighted an affinity constant of 7.3±0.3 mg ml−1 between the nanobiosystem and the sugar, and a detection sensitivity of 0.13±0.06 a.u./mg ml−1.