Hasanah, Uswatun Preparation and Characterization of a Pectin Membrane-Based Optical pH Sensor for Fish Freshness Monitoring. [electronic resource] - Biosensors Apr 2019 Publication Type: Journal Article ISSN: 2079-6374 Standard No.: 10.3390/bios9020060 doi Subjects--Topical Terms: Biosensing Techniques--methodsFish Products--standardsFood Analysis--methodsHydrogels--chemistryHydrogen-Ion ConcentrationIonophores--chemistryMembranes, ArtificialPectins--chemistrySpectrophotometry--methods