Ultrasensitive diffraction gratings based on smart hydrogels for highly selective and rapid detection of trace heavy metal ions

• Published in: Journal of materials chemistry. C, Materials for optical and electronic devices Materials for optical and electronic devices, 2018, Vol.6 (42), p.11356-11367
• Main Authors: Peng, Han-Yu, Wang, Wei, Gao, Fuhua, Lin, Shuo, Liu, Lu-Yue, Pu, Xing-Qun, Liu, Zhuang, Ju, Xiao-Jie, Xie, Rui, Chu, Liang-Yin
• Format: Article
• Language: English
• Subjects: Acrylamide; Change detection; Copper; Gratings (spectra); Heavy metals; Hydrogels; Isopropylacrylamide; Lead; Metal ions; Optical communication; Phase transitions
• ISSN: 2050-7526; 2050-7534
• DOI: 10.1039/C8TC02347F

An ultrasensitive grating system based on stimuli-responsive hydrogels with ultra-low detection limit for highly-selective and rapid detection of trace heavy metal ions is developed. The excellent detection performance of trace heavy metal ions is demonstrated by using poly( N -isopropylacrylamide- co -benzo-18-crown-6-acrylamide) hydrogel gratings with well-designed molecular structures for detecting trace Pb 2+ in water. The hydrogel grating with nanometer-sized height synergistically combines the fast thermo-responsive volume phase transition of poly( N -isopropylacrylamide) backbones and the highly-selective Pb 2+ recognition of benzo-18-crown-6 moieties to achieve enhanced Pb 2+ -induced swelling changes for detecting trace Pb 2+ . By integrating the hydrogel grating into a simple optical detection system, the signal of trace Pb 2+ can be efficiently converted and amplified into optical intensity signals for ultrasensitive, highly-selective and rapid detection of Pb 2+ with concentration as low as 10 −9 M. This hydrogel grating system provides an efficient strategy for ultrasensitive detection of trace heavy metal ions for protection of the environment and human health.