Figure 2.The flowchart of DNA immobilization and hybridization process.2.3. Prism Coupler SetupThe films are brought into contact with the base of a prism until there is an air gap in the nanometer level between the film and the prism. An incident laser beam hits the base of the prism and total internal reflection occurs due to the higher refractive index of the prism (np) when compared to air. The reflected laser beam strikes to a photodetector and the light intensity is measured. At certain angles of incidence, ��, tunneling of photons takes place. The tunneling photons go through the air gap and enter the dielectric film, which causes an instant drop in the intensity of light reaching the detector .
For this tunneling to occur properly, the air gap between the prism and the film should be smaller than the wavelength of the incident beam.
The angle �� determines the phase velocity of the incident wave in the prism and in the gap, along the surface of the films, ��(i) = (c/np) sin ��. The strong coupling of the light only occurs when �� is chosen such that ��(i) equals to the phase velocity of one of the characteristic modes  (Figure 3). These angles are called mode angles.Figure 3.Schematic view of the experimental setup.3.?Results and DiscussionThe chemical structure of SiO2-TiO2 hybrid coatings was investigated by FTIR measurements.
The peak occurring around 940 cm-1 corresponds to the vibration of Si�CO�CTi bonds and the peak at around 1,030 cm-1 is a
The technology used for environment monitoring is evolving from manual and semi-mechanical systems into new sensing Brefeldin_A platforms where wireless sensor networks endowed with new communication protocols such as the IEEE 802.
15.4  and ZigBee  are offering new and fascinating ways of connecting embedded systems to the environment by converting Cilengitide physical phenomena into an electronic response. Wireless Sensor Networks (WSNs) are a new wireless technology which is currently deployed in both civil and military applications to achieve different sensing functions. These include: environment observation, healthcare and medical monitoring, home security, machine failure diagnosis, chemical/biological detection, plant monitoring, battlefield surveillance and enemy tracking. WSNs  are deployed in large numbers of tiny sensor nodes, each node being regarded as a cheap computer that can perform sensing, computation and communication. The sensor nodes operate with low power battery to perform physical, chemical and biological sensing activities.