Nanocomposite-Decorated Filter Paper as a Twistable and Water-Tolerant Sensor for Selective Detection of 5 ppb-60
Lingling Du1, Dongliang Feng1, Xiaxia Xing1
1Tianjin Key Laboratory of Optoelectronic Sensor and Sensing Network Technology, Engineering Research Center of Thin Film Optoelectronics Technology, Ministry of Education and Department of Electronics, College of Electronic Information and Optical Engineering, Nankai University, Tianjin 300350, P. R. China.
Abstract:
Ammonia (NH3) sensors proposed for the simultaneous exhalation diagnosis, environmental pollution monitoring, and industrial leakage alarm require high flexibility, selectivity, stability, humidity tolerance, and wide-concentration-range detection; however, technical challenges still remain. Herein, twistable and water-tolerant paper-based sensors integrated over surgical masks have been developed for NH3 detection at room temperature, via decorating specially designed ternary nanocomposites (ternary-NCs) on the commercial filter paper. The NCs consist of a multiwalled carbon nanotube framework with a polypyrrole nanolayer and are further loaded with Pt nanodots. Benefiting from the synergy effect of ternary components, the ternary-NCs exhibit an ultrasensitive response to 5 ppb-60 v/v% NH3 and present high selectivity confirmed by the theory calculations. Remarkably, the filter-paper-based sensors possess outstanding stability against twisting 0-1080°, along with excellent cuttability and foldability. Critically, such paper-based sensors can be integrated over surgical masks for simulated exhaled diagnosis and display superior water tolerance even being immersed in water for 24 h. Practically, the detecting accuracy of the filter-paper-based sensor toward the simulated exhaled NH3, environmental NH3 pollution, and industrial NH3 leakage is validated using ion chromatography.
