title: Diffractive optical chemical sensor based on light absorption.
abstract: A new type of chemical sensor based on light absorption is proposed. An array of zones alternatively containing the pH indicator thymolphthalein is formed in a gelatin film. By changing the sample solution from acidic to alkaline, a blue stripe appears in the gelatin film. This acts as a transmission grating and diffracts the introduced laser beam. Theory predicts that this method, which is based on light absorption/beam diffraction, is as sensitive as or more sensitive than fluorometry.
authors.affiliation: Department of Chemical Systems and Engineering, Graduate School of Engineering, Kyushu University, Hakozaki, Fukuoka 812, Japan.
authors.forename: F
authors.initials: F
authors.lastname: Nakajima
authors.forename: Y
authors.initials: Y
authors.lastname: Hirakawa
authors.forename: T
authors.initials: T
authors.lastname: Kaneta
authors.forename: T
authors.initials: T
authors.lastname: Imasaka