Highly Response and Sensitivity Chitosan-Polyvinyl alcohol Based Hexanal Sensors Nur Zuraihan Abd Wahab, Irwana Nainggolan, Tulus Ikhsan Nasution, Mohd Nazree Derman and Devi Shantini MATEC Web Conf., 78 (2016) 01072 Published online: 07 October 2016 DOI: 10.1051/matecconf/20167801072