This work presents the first step toward a glucose biosensor using surface-enhanced Raman spectroscopy (SERS). Historically, has been extremely difficult to detect by SERS because it small normal cross section and adsorbs weakly or not at all bare silver surfaces. In this paper, we report systematic study of direct detection SERS. Glucose is partitioned into an alkanethiol monolayer adsorbed on film over nanosphere (AgFON) surface thereby, preconcentrated within 0−4 nm thick zone...

This paper presents the first in vivo application of surface-enhanced Raman scattering (SERS). SERS was used to obtain quantitative glucose measurements from an animal model. Silver film over nanosphere surfaces were functionalized with a two-component self-assembled monolayer, and subcutaneously implanted Sprague−Dawley rat such that concentration interstitial fluid could be measured by spectroscopically addressing sensor through optical window. The had relatively low error (RMSEC = 7.46...

A new, mixed decanethiol (DT)/mercaptohexanol (MH) partition layer with dramatically improved properties has been developed for glucose sensing by surface-enhanced Raman spectroscopy. This work represents significant progress toward our long-term goal of a minimally invasive, continuous, reusable sensor. The DT/MH-functionalized surface greater temporal stability, demonstrates rapid, reversible partitioning and departitioning, is simpler to control compared the tri(ethylene glycol) monolayer...

This research presents the achievement of significant milestones toward development a minimally invasive, continuously monitoring, glucose-sensing platform based on optical quantitation glucose in interstitial fluid. We expand our initial successes measurement by surface-enhanced Raman scattering (SERS), demonstrating substantial improvements not only quality and properties substrate system itself but also robustness methodology amenability technique to compact, diode laser-based...

This letter presents the first quantitative, in vivo, transcutaneous glucose measurements using surface enhanced Raman spectroscopy (SERS). Silver film over nanosphere (AgFON) surfaces were functionalized with a mixed self-assembled monolayer (SAM) and implanted subcutaneously Sprague−Dawley rat. The concentration was monitored interstitial fluid. SER spectra collected from sensor chip through skin spatially offset (SORS). combination of SERS SORS is powerful new approach to challenging...

This paper presents the latest progress on quantitative, in vivo, transcutaneous glucose sensing using surface enhanced spatially offset Raman spectroscopy (SESORS). Silver film over nanosphere (AgFON) surfaces were functionalized with a mixed self-assembled monolayer (SAM) and implanted subcutaneously Sprague–Dawley rats. The concentration was monitored interstitial fluid of six separate results demonstrated excellent accuracy consistency. Remarkably, root-mean-square error calibration...

Surface-enhanced spatially offset Raman spectroscopy (SESORS) is a label-free vibrational that has the potential for in vivo imaging. Previous SESORS experiments have been limited to acquiring spectra using SERS substrates implanted under skin or from nanoparticles embedded tissue. Here we present measurements of active coated with reporter molecule (nanotags) acquired, first time, through bone. We demonstrate ability measure various thicknesses (3-8 mm) also show diluted nanotag samples (~2...

Lactate production under anaerobic conditions is indicative of human performance levels, fatigue, and hydration. Elevated lactate levels result from several medical including congestive heart failure, hypoxia, diabetic ketoacidosis. Real-time detection can therefore be useful for monitoring these conditions, posttrauma situations, in evaluating the physical condition a person engaged strenuous activity. This paper represents proof-of-concept demonstration sensor based on surface-enhanced...

Aqueous environments pose unique challenges to the use of nanoparticle platforms for development robust in vitro and vivo sensors. A method is developed anchor nanoparticles into a glass substrate by combining nanosphere lithography (NSL) reactive ion etching (RIE) create mechanically durable sensing platform. The increased mechanical performance attributed higher adhesion strength NSL anchored shallow nanowells formed RIE. Using atomic force microscopy (AFM), conventional arrays were...

Needs which have arisen in ophthalmic research motivated the development of a six-degree-of-freedom parallel micromanipulator. The first application tool will be treatment retinal venous occlusion, for micron-scale spherical movement glass micropipette tip inside eye is required. initial operation mode open loop, while future force-reflecting bilateral (macro-master/micro-slave) arrangement. Presented here are some design criteria, mathematical tools used evaluating various manipulator...

We report the effect of changes in corneal hydration on refractive index cornea. Using optical coherence tomography (OCT), geometrical thickness and group bovine cornea were derived simultaneously as was varied. The then calculated from thickness. increased non-linearly dehydrated. In addition, a simple mathematical model developed, based assumption that occur only interfibrilar space with constant water content within collagen fibrils. Good agreement between experimental results supports...

We have discovered a micro/nanopatterning technique based on the patterning of PDMS membrane/film, which involves bonding structure/stamp (that has desired patterns) to film. The technique, we call "bond-detach lithography", was demonstrated (in conjunction with other microfabrication techniques) by transferring several micro- and nanoscale patterns onto variety substrates. Bond-detach lithography is parallel process in master mold can be used many times, particularly simple inexpensive.

Spreading of a new surfactant in the presence pre-existing distribution is investigated both experimentally and theoretically for thin viscous substrate. The experiments are designed to provide better understanding fundamental interfacial fluid dynamics spreading surfactants instilled into lung. Quantitative measurements rates were conducted using fluorescent that was excited by argon laser light as it spread on an air–glycerin interface petri dish. It found impedes spreading. However,...

When a liquid is instilled in the pulmonary airways during medical therapy, method of instillation affects distribution throughout lung. To investigate fluid transport dynamics, exogenous surfactant (Survanta) mixed with radiopaque tracer into tracheae vertical, excised rat lungs (ventilation 40 breaths/min, 4 ml tidal volume). Two methods are compared: For case A, drains by gravity upper followed inspiration; for B, initially forms plug trachea, inspiration. Experiments continuously...

The mesothelial cells that form the visceral pleura of lung are subjected to physical forces such as stretch due expansion and fluid shear stress sliding motion against chest wall. In this study, effect mechanical on production growth factors by was investigated. Rat (RVPM) were exposed perfusing a column cell-covered beads. RVPM grown silicone elastomer cyclic strain applying an oscillating vacuum bottom wells using Flexercell apparatus. Fluid (5.2-15.7 dyn/cm2) stimulated release...

The initial steps toward a miniature, field portable sensor based on surface-enhanced Raman spectroscopy (SERS) are presented. It is demonstrated that low-cost miniaturized system can be used in place of larger, higher-cost conventional system. This was developed by sequentially replacing components laboratory scale with smaller, lower-cost, commercially available components. For example, green laser pointer as the excitation source, reflectance probe fiber-optic cable for delivery and...

Oxidative stress has been implicated in a variety of diseases the eye. In several other tissues, keratinocyte growth factor (KGF) shown to prevent negative cellular changes associated with oxidative insult, such as permeability increases and nuclear DNA damage. this study, we looked at whether KGF provided these same protective effects cultured human retinal pigmented epithelial (RPE) cells (ARPE-19).Reverse transcriptase-polymerase chain reaction (RT-PCR) using published primer pair...