The invention relates to an analytical aid comprising a surface that is at least partly coated with a hydrophilic coating, said hydrophilic coating containing nanoparticles with a silicon dioxide structure and an average particle size ranging from 1 to 500 nm, determined according to DIN ISO 22412:2008. The invention further relates to a method for producing an analytical aid comprising a surface that is at least partly coated with a hydrophilic coating, said hydrophilic coating containing nanoparticles with a silicon dioxide structure and an average particle size ranging from 1 to 500 nm, determined according to DIN ISO 22412:2008. The invention likewise relates to an analytical aid that can be produced using said method and to a sampling device containing the aforementioned analytical aid that is at least partly coated.
