The authors thank the National Institutes of Health for financially supporting this work under grant 2R01 EB 004132. The authors also gratefully acknowledge Dr. Matti Ben-Moshe and Lee Stunja for many helpful discussions.
Poly(vinyl alcohol) Rehydratable Photonic Crystal Sensor Materials†
Article first published online: 9 APR 2008
Copyright © 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim
Advanced Functional Materials
Volume 18, Issue 8, pages 1186–1193, April 25, 2008
How to Cite
Muscatello, M. M. W. and Asher, S. A. (2008), Poly(vinyl alcohol) Rehydratable Photonic Crystal Sensor Materials. Adv. Funct. Mater., 18: 1186–1193. doi: 10.1002/adfm.200701210
- Issue published online: 23 APR 2008
- Article first published online: 9 APR 2008
- Manuscript Revised: 26 JAN 2008
- Manuscript Received: 5 OCT 2007
- National Institutes of Health. Grant Number: 2R01 EB 004132
- poly(vinyl alcohol);
- photonic crystals
We developed a new photonic crystal hydrogel material based on the biocompatible polymer poly (vinyl alcohol) (PVA), which can be reversibly dehydrated and rehydrated, without the use of additional fillers, while retaining the diffraction and swelling properties of polymerized crystalline colloidal arrays (PCCA). This chemically modified PVA hydrogel photonic crystal efficiently diffracts light from the embedded crystalline colloidal array. This diffraction optically reports on volume changes occurring in the hydrogel by shifts in the wavelength of the diffracted light. We fabricated a pH sensor, which demonstrates a 350 nm wavelength shift between pH values of 3.3 and 8.5. We have also fabricated a Pb+2 sensor, in which pendant crown ether groups bind lead ions. Immobilization of the ions within the hydrogel increases the osmotic pressure due to the formation of a Donnan potential, swelling the hydrogel and shifting the observed diffraction in proportion to the concentration of bound ions. The sensing responses of rehydrated PVA pH and Pb+2 sensors were similar to that before drying. This reversibility of rehydration enables storage of these hydrogel photonic crystal sensors in the dry state, which makes them much more useful for commercial applications.