Studi penentuan distribusi ukuran nanopartikel platina menggunakan mikroelektroda hydrogenated boron doped diamond (hbdd) dan oxidized boron doped diamond (OBDD) dengan hidrogen peroksida = Study on determination of platinum nanoparticles sized distribution using hydrogenated boron doped diamond (HBDD) and oxidized boron doped diamond (obdd) microelectrodes with hydrogen peroxide