A simple approach to covalent functionalization of boron nitride nanotubes

► A novel and simple method for the chemical functionalization of boron nitride nanotubes (BNNTs) is presented. ► Surface is modified through 3-aminopropyl-triethoxysilane (APTES), thus exposing amino groups on the BNNT walls. ► The efficacy of the procedure is assessed with EDS and XPS analyses. ► In vitro toxicity and cell up-take have been evaluated.