Sensitivity enhancement of gold nanospheres assisted CO2 laser tapered optical fiber for refractive index sensor by Nurul Hidayat, Nurul Hidayat, Abd. Aziz, Muhammad Safwan, Hadi Nur, Hadi Nur, Ahmad Taufiq, Ahmad Taufiq, Nandang Mufti, Nandang Mufti, Rino Rakhmata Mukti, Rino Rakhmata Mukti, Bakhtiar, Hazri