Underlying Subwavelength Aperture Architecture Drives the Optical Properties of Microcavity Surface Plasmon Resonance Sensors.

Microcavity surface plasmon resonance sensors (MSPRSs) develop out of the classic surface plasmon resonance technologies and aim at producing novel lab-on-a-chip devices. MSPRSs generate a series of spectral resonances sensitive to minute changes in the refractive index. Related sensitivity studies and biosensing applications are published elsewhere.

Evidence of learning and memory in the juvenile dwarf cuttlefish Sepia bandensis.

Measuring behavior in the form of numerical data is difficult, especially for studies involving complex actions. DanioVision is a closed-chamber system that utilizes subject tracking to comprehensively record behavior, while also mitigating the influence of environmental conditions. We used DanioVision to record activity of juvenile dwarf cuttlefish (Sepia bandensis) during the inaccessible prey (IP) procedure, a memory experiment in which cuttlefish learn to inhibit capture attempts towards inaccessible prey.

Label-free microcavity biosensors: steps towards personalized medicine.

Personalized medicine has the potential to improve our ability to maintain health and treat disease, while ameliorating continuously rising healthcare costs. Translation of basic research findings to clinical applications within regulatory compliance is required for personalized medicine to become the new foundation for practice of medicine. Deploying even a few of the thousands of potential diagnostic biomarkers identified each year as part of personalized treatment workflows requires clinically efficient biosensor technologies to monitor multiple biomarkers in patients in real time.

Microfluidic devices integrating microcavity surface-plasmon-resonance sensors: glucose oxidase binding-activity detection.

We have developed miniature (approximately 1 microm diameter) microcavity surface-plasmon-resonance sensors (MSPRS), integrated them with microfluidics, and tested their sensitivity to refractive-index changes. We tested their biosensing capability by distinguishing the interaction of glucose oxidase (M(r) 160 kDa) with its natural substrate (beta-D-glucose, M(r) 180 Da) from its interactions with nonspecific substrates (L-glucose, D-mannose, and 2-deoxy-D-glucose). We ran the identical protocol we had used with the MSPRS on a Biacore 3000 instrument using their bare gold chip.

Compact microfluidic structures for generating spatial and temporal gradients.

We present an improved microfluidic design for generating spatial and temporal gradients. The basic functional elements are bifurcated and trifurcated channels used to split flow between two and three channels, respectively. We use bifurcated channels on the exterior of the channel manifold and trifurcated channels in the interior with mixing tees to recombine flows.

Submicrometer cavity surface plasmon sensors.

A miniaturized spherical surface plasmon sensor for measuring the binding kinetics of unlabeled molecules is introduced. The sensor has a submicrometer footprint with a sensitivity that rivals that of state-of-the-art commercial planar surface plasmon sensors, which makes it valuable for applications requiring integration of detection of molecular species in microfluidic channels. The basic principle of the sensor is exploiting the wavelength shifts of the cavity resonances of a metal-coated submicrometer sphere embedded in an opaque metal film due to molecular adsorption.

Chemotaxis assays of mouse sperm on microfluidic devices.

Sperm chemotaxis is an area of significant interest to scientists involved in reproductive science. Understanding how and when sperm cells are attracted to the egg could have profound effects on reproduction and contraception. In an effort to systematically study this problem, we have fabricated and evaluated a microfluidic device to measure sperm chemotaxis.

Three-dimensional mapping of the light intensity transmitted through nanoapertures.

A general method to map the 3D spatial distribution of light emerging from nanoscale apertures is presented that uses photolithographic techniques to create polymer replicas of the intensity distribution. The resulting features varied with aperture diameter and exposure time and showed good correlation with theory. This method provides direct visualization of the intensity distribution in close proximity to nanostructures and overcomes limitations imposed by physical probes where the contribution of the probe to the map requires deconvolution.