Multiplexed suspension array platform for high-throughput protein assays

A multiplexed suspension array platform, based on SU8 disks patterned with machine-readable binary identification codes is presented. Multiple probe molecules, each attached to individual disks with different unique codes, provide multiplexed detection of targets in a small sample volume. The experimental system consists of a microfluidic chamber for arraying the particles in a manner suitable for high throughput imaging using a simple fluorescent microscope, together with custom software for automated code readout and analysis of assay response. The platform is demonstrated with a multiplexed antibody assay targeting 3 different human inflammatory cytokines. The suitability of the platform for other bio-analytical applications is discussed.<br/

A study of environmental effects on the attenuation of chalcogenide optical fibre

The attenuation of a number of chalcogenide glass optical fibres has been studied with regard to their exposure the environment. We demonstrate that gallium lanthanum sulfide (Ga:La:S) based glasses appear to be as resilient if not more so than arsenic sulfide (As2S3) glass to the attack of moisture when stored uncoated in ambient conditions for various periods exceeding 1 year. The increase in the characteristic OH' attenuation peak was ~3–4 dB/m for all fibres following storage. Given the significant improvements achieved in As2S3 glass technology over recent years we believe that Ga:La:S based fibres can also be improved to at least match these levels with the advantage of being non-toxic and having a significantly higher melting temperature. Studies of the time-dependant attenuation of the optical fibres during immersion in water have also been carried out. These results show that the deleterious effect of moisture on these glasses occurs over a short time, ~24 h, thus having implications on the treatment and storage of fibre preforms prior to optical fibre drawing

Superimposed Nanostructured Diffraction Gratings as High Capacity Barcodes for Biological and Chemical Applications

We describe a new non-contact high capacity optical tagging technique for bead based assays, based on the use of nanostructured barcodes. The tags are generated from a number of superimposed diffraction gratings. With one-dimensional diffraction, capacity for up to 68,000 distinguishable tags has been demonstrated, with a theoretical capacity of up to 109 tags. Extension into two dimensions increases this theoretical limit to 1021 tags

Nanofabrication of SiC templates for direct hot embossing for metallic photonic structures and meta materials

A reliable nanofabrication process for hard templates in SiC amorphous film was developed. The process involves high resolution electron beam lithography and reactive ion etch for nanosize structures in SiC. Study of the RIE property in SiC narrow trenches and dot array indicates that various profiles of sidewall can be achieved by controlling the etch power and ratio of fluorine-based gas mixture. It was also discovered that SiC material is RIE lag free in dry etch, which opens up a broader applications for deep and narrow structures. Applications of SiC templates for hot embossing into metals and plastics prove that the SiC templates formed in amorphous film are hard enough for the fabrications of metallic photonic structures and meta materials