Abstract
In this contribution, chemical sensor for the detection of aqueous ammonia has been fabricated using UV-curable polyurethane acrylate (PU) and nanohybrids (NH-1, NH-3 and NH-5). PU has been prepared by reacting polycaprolactone triol (PCLT) and isophorone diisocyanate (IPDI) while the nanohybrids, NH-1, NH-3, and NH-5 have been synthesized by solution blending method using PU with 1, 3, and 5 wt% loading levels of C-20B. PU and their nanohybrids showed higher sensitivity investigated by I-V, technique using aqueous ammonia as a target chemical. All the nanohybrids showed higher sensitivity as compared to neat PU. The sensitivity increased with increase in clay content and the nanohybrid containing 5 wt% of clay showed the highest sensitivity (8.5254 mu A cm(-2) mM(-1)) with the limit of detection (LOD) of 0.0175 +/- 0.001 mu M, being 7.8 times higher than pure PU. The calibration plot for all the sensors was linear over the large range of 0.05 mu M to 0.05 mu M. The response time of the fabricated sensor was <10.0 s. Therefore, one can fabricate efficient aqueous ammonia sensor by utilization of nanohybrid as an efficient electron mediator. (C) 2011 Elsevier B.V. All rights reserved.