Design of nanosensors based on optic fibre

A telecommunications engineer from Pamplona, Ignacio del Villar Fernández, has developed two simulation tools for designing nanosensors based on optic fibres. For some structures analysed the sensitivity of the devices have been improved by up to a factor of ten. The results and conclusions of this research are outlined in his PhD thesis, Theoretical analysis and fabrication of nanostructures with Electrostatic Self-Assembly Monolayer process, recently defended at the Public University of Navarre. Sensors for oxygenated water and glucose The aim of the PhD was the application of the electrostatic self-assembly monolayer (ESAM) methods to the development and analysis of structures with the periodic modulation of the refractive index. This method, enabling the deposition of very thin layers – in the order of tens of nanometers - onto structures, is also able to include a wide range of substances such as colourings, enzymes and DNA, for applications in bioengeneering. In order to predict the behaviour of these structures, two simulation tools have been developed: Nanosim and Ipgsim. The first of these, Nanosim, has been marketed through the North American company, Nanosonic Inc. This simulation tool is used to analysis periodic structures in one, two or three dimensions. Moreover, the simplest of these structures – a nanocavity at one end of an optic fibre, has been used to develop a sensor for oxygenated water and a biosensor for glucose. The detector or sensor for oxygenated water has not been marketed but can be applied in biology for chemical reactions where oxygenated water is involved. The advantage of these optic fibre sensors is that they are hair thin and so may be inserted anywhere. Just by inserting the tip of one end of the nanosensor in a very small solution, measurements can be made. Moreover, the other advantage is that, being an optic fibre sensor, it is immune to electromagnetic interference. The second simulation tool is known as Ipgsim and its function is the analysis of long-period grating (LPGs) Bragg networks – optic fibres with special properties for sensing. This involves a technology that has been making great headway over the past decade in the field of optic communications and that of sensors. Within this last field, conditions for improving the sensitivity of LPGs tenfold have been analysed with lpgsim. In the PhD thesis, by means of applying the technique of nanodeposition, the predicted enhancement of the sensitivity of these devices was corroborated experimentally. "Source":[ http://www.basqueresearch.com/berria_irakurri.asp?Gelaxka=1_1&Berri_Kod=896&hizk=I].

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