Diffractive optical chemical sensor based on light absorption

Authors
Nakajima, F Hirakawa, Y Kaneta, T Imasaka, T
Citation
F. Nakajima et al., Diffractive optical chemical sensor based on light absorption, ANALYT CHEM, 71(13), 1999, pp. 2262-2265
Citations number
8
Categorie Soggetti
Chemistry & Analysis","Spectroscopy /Instrumentation/Analytical Sciences
Journal title
ANALYTICAL CHEMISTRY
ISSN journal
00032700 → ACNP
Volume
71
Issue
13
Year of publication
1999
Pages
2262 - 2265
Database
ISI
SICI code
0003-2700(19990701)71:13<2262:DOCSBO>2.0.ZU;2-#
Abstract
A new type of chemical sensor based on light absorption is proposed. An arr ay of zones alternatively containing the pH indicator thymolphthalein is fo rmed in a gelatin film. By changing the sample solution from acidic to alka line, a blue stripe appears in the gelatin film. This acts as a transmissio n grating and diffracts the introduced laser beam. Theory predicts that thi s method, which is based on light absorption/beam diffraction, is as sensit ive as or more sensitive than fluorometry.