The gas-detection properties of light-emitting diatoms
The gas-detection properties of light-emitting diatoms
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DOI：
10.1002/adfm.200701124
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发表时间：
2008-04-25
影响因子：
19
通讯作者：
Maddalena, Pasqualino
中科院分区：
文献类型：
--
作者：
Lettieri, Stefano;Setaro, Antonio;Maddalena, Pasqualino
近年来，基于仿生方法研究了由活硅藻产生的多孔二氧化硅结构在纳米工程中的应用。我们重点研究了硅藻的气敏特性：对不同种类硅藻的研究表明，即使周围气体环境的微小变化也会影响硅藻的光致发光，在二氧化氮的情况下，检测限为百万分之几。本文从气体分子吸附引起的辐射态（很可能是表面氧空位）的抑制来讨论“静态型”发光猝灭现象。该模型允许用全光学方法测量脱附的自由能：得到的值表明涉及化学吸附过程，与观察到的吸收/脱附动力学一致。这一发现鼓励了对硅藻作为检测气体种类的低成本生物传感器的研究。
In recent years, the porous silica structures (frustules) created by living diatoms have been studied for several nanoengineering applications based on biomimetic approaches. We focus on the gas-sensing properties of diatoms: investigation of different species shows that the photoluminescence emission of frustules is affected by even small modifications of the surrounding gas environment, exhibiting a detection limit of few tenths of ppm in the case of nitrogen dioxide. A new understanding of this phenomenon is discussed here in terms of "static-type" luminescence quenching through suppression of radiative states (most probably surface oxygen vacancies) induced by adsorption of gas molecules. The modeling allows the free energy of desorption to be measured by all-optical means: the value obtained suggests that a chemisorption process is involved, in agreement with the observed absorption/desorption kinetics. The findings encourage investigation of diatoms as low-cost biological transducers for detection of gas species.