کد مقاله | کد نشریه | سال انتشار | مقاله انگلیسی | نسخه تمام متن |
---|---|---|---|---|
7148796 | 1462102 | 2013 | 7 صفحه PDF | دانلود رایگان |
عنوان انگلیسی مقاله ISI
Ammonia vapor sensor based on CdSe/SiO2 core-shell nanoparticles embedded in sol-gel matrix
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موضوعات مرتبط
مهندسی و علوم پایه
شیمی
شیمی آنالیزی یا شیمی تجزیه
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چکیده انگلیسی
A high-performance ammonia vapor sensor is proposed comprising CdSe/SiO2 core-shell nanoparticles embedded in a sol-gel matrix immobilized on the tip of an optical fiber. The experimental results show that the luminescence intensity of the CdSe/SiO2 nanoparticles reduces significantly when exposed to ammonia vapor. The fluorescence quenching effect is thought to be caused by the adsorption of the ammonia molecules at the trapped sites on the surface of the CdSe quantum dots (QDs). In addition, the proposed sensor exhibits good linearity for ammonia vapor concentrations between 10 and 400Â ppm, and has a detection limit of as little as 1.2Â ppm. Moreover, the sensor has a response time of 6.1Â s when switching from pure N2 to a mixed N2-ammonia vapor and 942.2Â s when switching in the reverse direction. Importantly, the signal changes are fully reversible when switching repeatedly between the two gaseous environments. Overall, the results show that the proposed sensor has many key advantages compared to optical sensors based on organic sensitive dye, including a higher response (I0/I), an improved chemical stability, and full reversibility.
ناشر
Database: Elsevier - ScienceDirect (ساینس دایرکت)
Journal: Sensors and Actuators B: Chemical - Volume 188, November 2013, Pages 702-708
Journal: Sensors and Actuators B: Chemical - Volume 188, November 2013, Pages 702-708
نویسندگان
Ti-Wen Sung, Yu-Lung Lo,