Optical Ammonia Sensor Based on Upconverting Luminescent Nanoparticles
Optical Ammonia Sensor Based on Upconverting Luminescent Nanoparticles
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DOI：
10.1021/ac1007283
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发表时间：
2010-06-15
影响因子：
7.4
通讯作者：
Wolfbeis, Otto S.
中科院分区：
文献类型：
--
作者：
Mader, Heike S.;Wolfbeis, Otto S.
该传感器利用上转换发光现象，并且基于（a）使用NaYF 4：Yb，Er型的上转换纳米颗粒（UCNP），其可以用980 nm激光激发以给出绿色和红色发光，以及（B）固定在聚苯乙烯基质中的pH探针酚红。将传感器膜暴露于氨导致pH探针的560 nm吸收强烈增加，这又导致UCNP的绿色发射被屏蔽掉。相反，UCNP的红色发射不受氨的影响，可以作为参考信号。由于使用980 nm作为激发光源，所获得的光学信号完全没有样品的背景可见光和散射光。这在感测复杂基质中的氨的情况下是非常有利的。
The sensor exploits the phenomenon of upconversion luminescence and is based on (a) the use of upconverting nanoparticles (UCNPs) of the NaYF4:Yb,Er type that can be excited with 980 nm laser light to give a green and red luminescence and (b) the pH probe phenol red immobilized in a polystyrene matrix. Exposure of the sensor film to ammonia causes a strong increase in the 560 nm absorption of the pH probe which, in turn, causes the green emission of the UCNPs to be screened off. The red emission of the UCNPs, in contrast, remains unaffected by ammonia and can serve as a reference signal. Due to the use of 980 nm as the excitation light source, the optical signal obtained is completely free of background visible luminescence of the sample and of scattered light. This is highly advantageous in the case of sensing ammonia in complex matrixes.