1992 Volume 8 Issue 6 Pages 837-840
A bifurcated fiber-optic sensor for Zn2+, Cd2+ and Ga3+ ions was fabricated. Chitosan modified with 5-formyl-3-hydroxy-4-hydroxymethyl-2-methylpyridine was immobilized on an agarose gel and used as a fluorogenic probe. The reproducibility of the response to Zn2+ was within 5% in eight successive measurements at 5.0×10-5M (1M=1mol dm-3). A linear relationship with a correlation coefficient of 0.994 was obtained in the Zn2+ concentration range of 0-2.0×10-5M, and the detection limit was 1.0×10-6M (S/N=3). Cd2+ and Ga3+ ions were also detected, though with sensitivities somewhat lower than that for Zn2+.