Pengembangan sensor BOD berbasis rhodotorula mucilaginosa UICC Y-181 Terimobilisasi dalam gelatin dan alginat menggunakan elektroda emas dan boron-doped diamond termodifikasi nanopartikel emas = The development of BOD sensor based on rhodotorula mucilaginosa UICC Y-181 immobilized in gelatine and alginate matrix using gold and gold nanoparticles-modified boron-doped diamond electrodes