Chemical modification of Nitzschia panduriformis's frustules for protein and viral nanoparticle adsorption

► The frustule (diatom cell wall) was chemically modified to immobilize Cu2+ ions for protein and nanoparticle purification. ► (His)6-tagged green fluorescent protein binding was confirmed. ► Subviral particle binding to the Cu2+-coupled biosilica is higher than that using a commercial Ni-NTA resin.