We present a novel scheme based on sequential writing for fabrication of advanced fiber Bragg gratings. As opposed to earlier sequential methods this technique uses a cw UV laser source and allows for very precise control and repetitivity of the formation of the gratings. Furthermore it is possible to use high average irradiances without destroying the fiber, resulting in considerable reduction in fabrication time for complex gratings. The method has been applied to several test gratings, which proved its versatility and quality.

The blue OLED emission from a mobile phone was characterised, revealing a sharp emission band centred at λ = 445 nm with a 3dB bandwidth Δλ ~ 20 nm. It was used to excite Rhodamine 123 doped within a “giant” mesostructured silica sphere during fabrication through evaporative self-assembly of silica nanoparticles. Fluorescence was able to be detected using a standard optical microscope fitted with a green transmission pass filter and cooled CCD and with 1 ms exposure time demonstrating the potential of mobile platforms as the basis for portable diagnostics in the field.

Generation of large areas of graphene possessing high quality and uniformity will be a critical factor if graphene-based devices/sensors are to be commercialized. In this work, epitaxial graphene on a 2" SiC wafer was used to fabricate sensors for the detection of illicit drugs (amphetamine or cocaine). The main target application is on-site forensic detection where there is a high demand for reliable and cost-efficient tools. The sensors were designed and processed with specially configured metal electrodes on the graphene surface by utilizing a series of anchors where the metal contacts are directly connected on the SiC substrate. This has been shown to improve adhesion of the electrodes and decrease the contact resistance. A microfluidic system was constructed to pump solutions over the defined graphene surface that could then act as a sensor area and react with the target drugs. Several prototypic systems were tested where non-covalent interactions were used to localize the sensing components (antibodies) within the measurement cell. The serendipitous discovery of a wavelength-dependent photoactivity for amphetamine and a range of its chemical analogs, however, limited the general application of these prototypic systems. The experimental results reveal that the drug molecules interact with the graphene in a molecule dependent manner based upon a balance of $\pi$ -stacking interaction of the phenyl ring with graphene (p-doping) and the donation of the amine nitrogens lone pair electrons into the $\pi$ - $\pi$ *-system of graphene (n-doping).

The structure and physical properties of a thin titania sol-gel layer prepared on silicon and silica surfaces were examined. Spectroscopic (FTIR, UV-VIS spectroscopy), refractive index (ellipsometry) and microscopic (light microscopy and SEM/EDS) tools were used to examine both chemical uniformity and physical uniformity of the sol-gel glass layers. The conditions for the fabrication of uniform layers were established, and room temperature dopant incorporation was examined. The absorption bands of porphyrin-containing titania sol-gel layers were characterized. By addition of a metal salt to the titania layer, it was possible to metallate the free-base porphyrin within and change the UV-VIS absorbance of the porphyrin, the basis of metal detection using porphyrins. The metalloporphyrins were detected by localized laser ablation inductive coupled mass spectroscopy (LA-ICP-MS), indicating fairly uniform distribution of metals across the titania surface.

We constructed a type of sensor by depositing a solgel layer within the interior holes of a silica-structured fiber and, subsequently, coating this with an acid-responsive porphyrin. Protonation of the porphyrin by an acidic gas (HCl in this case), is detected by a large change in the visible spectrum. Compared to previous work on a liquid-core sensor in a structured optical fiber, the signal-to-noise ratio of this gas sensor shows a reduced signal strength, but the detection rate is increased about fortyfold.