Development of High Surface Area Organosilicate Nanoparticulate Thin Films for Use in Sensing Hydrophobic Compounds in Sediment and Water.

The scope of this study was to apply advances in materials science, specifically the use of organosilicate nanoparticles as a high surface area platform for passive sampling of chemicals or pre-concentration for active sensing in multiple-phase complex environmental media. We have developed a novel nanoporous organosilicate (NPO) film as an extraction phase and proof of concept for application in adsorbing hydrophobic compounds in water and sediment. We characterized the NPO film properties and provided optimization for synthesis and coatings in order to apply the technology in environmental media.

Modular design of paper based switches for autonomous lab-on paper micro devices.

This paper presents a new approach towards the design of paper based autonomous microfluidic devices. Autonomy in the device operation is achieved through the incorporation of mechanically actuated microfluidic switches that are versatile in their design and may be configured to be simple time triggered ON or OFF switches or more complex switches that can be timed to be in multiple states (timed ON, followed by timed OFF). These switches are self-contained and require no external power for their operation, deriving their functionality solely through stored elastic energy.

Re-usable PDMS stamps for non-destructive fluorescence evaluation and imaging of thin film photonic structures.

We report on a non-destructive method for evaluating fluorescence emission from fluorophores placed upon engineered photonic structures. Our method utilizes re-usable, fluorescent thin film coated polydimethylsiloxane (PDMS) stamps. We harness the inherent characteristics of PDMS slabs; their ability to form conformal contact through van der Waals interactions in bringing the coated fluorescent layer on PDMS into close proximity of the photonic structure of interest.

Nanomaterial processing using self-assembly-bottom-up chemical and biological approaches.

Nanotechnology is touted as the next logical sequence in technological evolution. This has led to a substantial surge in research activities pertaining to the development and fundamental understanding of processes and assembly at the nanoscale. Both top-down and bottom-up fabrication approaches may be used to realize a range of well-defined nanostructured materials with desirable physical and chemical attributes.

Femtogram-level detection of Clostridium botulinum neurotoxin type A by sandwich immunoassay using nanoporous substrate and ultra-bright fluorescent suprananoparticles.

We report a simple, robust fluorescence biosensor for the ultra-sensitive detection of Clostridium botulinum Neurotoxin Type A (BoNT/A) in complex, real-world media. High intrinsic signal amplification was achieved through the combined use of ultra-bright, photostable dye-doped nanoparticle (DOSNP) tags and high surface area nanoporous organosilicate (NPO) thin films. DOSNP with 22 nm diameter were synthesized with more than 200 times equivalent free dye fluorescence and conjugated to antibodies with average degree of substitution of 90 dyes per antibody, representing an order of magnitude increase compared with conventional dye-labeled antibodies.

Confeito-like assembly of organosilicate-caged fluorophores: ultrabright suprananoparticles for fluorescence imaging.

We report ultrabright, photostable, sub-25 nm nanoparticle agglomerates (suprananoparticles) assembled from a few hundred 3.3 ± 0.9 nm units, each hosting on average a single rhodamine 6G (Rh6G) dye molecule encased in a thin organosilicate cage.

A comparative evaluation of microarray slides as substrates for the development of protease assay biosensors.

The application of commercially available microarray slides as substrates for fluorogenic protease assays has been explored in terms of binding efficiency, stability, and activity. A fluorescent, biotinylated substrate for botulinum neurotoxin A (BoNTA) was attached via self-assembled monolayer of Streptavidin to amine-reactive aldehyde, epoxy, hydrogel, and polymer slides. Nexterion Slide P® was found to have optimal protein binding efficiency and stability of the slides examined.

Sub-minute formation of supported nanoporous mesoscale patterns programmed by surface energy.

We demonstrate an original and powerful concept for elaborating spontaneous, high fidelity patterns of nanoporosity from nanoscale building blocks using patterned surface chemistry (i.e., "surface energy gating") to corral the growth of colloidal structures at a solid surface.

Characterization of a novel ultra low refractive index material for biosensor application.

Nanoporous materials can provide significant benefits to the field of biosensors. Their size and porous structure makes them an ideal tool for improving sensor performance. This study characterized a novel ultra low index of refraction nanoporous organosilicate (NPO) material for use as an optical platform for fluorescence-based optical biosensors.

Entropy driven spontaneous formation of highly porous films from polymer-nanoparticle composites.

Nanoporous materials have become indispensable in many fields ranging from photonics, catalysis and semiconductor processing to biosensor infrastructure. Rapid and energy efficient process fabrication of these materials is, however, nontrivial. In this communication, we describe a simple method for the rapid fabrication of these materials from colloidal dispersions of Polymethyl Silsesquioxane nanoparticles.