Diffractive optical chemical sensor based on light absorption

Fumihiro Nakajima, Yasuyuki Hirakawa, Takashi Kaneta, Totaro Imasaka

Research output: Contribution to journalArticlepeer-review

27 Citations (Scopus)


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.

Original languageEnglish
Pages (from-to)2262-2265
Number of pages4
JournalAnalytical Chemistry
Issue number13
Publication statusPublished - Jan 1 1999
Externally publishedYes

ASJC Scopus subject areas

  • Analytical Chemistry


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