Noninvasive Blood Glucose Sensors Based on Near‐Infrared Spectroscopy

Geddes

2003

107

We have developed a range of glucose sensing contact lenses, using a daily, disposable contact lens embedded with newly developed boronic acid containing fluorophores. Our findings show that our approach may be suitable for the continuous monitoring of tear glucose levels in the range 50-1000 µM, which typically track blood glucose levels, which are ≈5-10 fold higher. Our non-invasive approach may well offer an alternative solution to current invasive glucose monitoring techniques for diabetes, such as "finger pricking."

Section: Introductionmentioning

confidence: 99%

A Glucose Sensing Contact Lens: A Non-Invasive Technique for Continuous Physiological Glucose Monitoring

Badugu

Geddes

2003

107

“…One of the major challenges in the management of diabetes is the monitoring of glucose concentrations. Despite intensive efforts [1][2][3][4][5], no method is currently available for the continuous non-invasive monitoring of blood glucose.…”

Section: Introductionmentioning

confidence: 99%

Saccharide Sensing Using Gold and Silver Nanoparticles-A Review

Aslan

Zhang

et al. 2004

133

We review new methodologies for glucose sensing from our laboratories based on the specific biological interactions between Con A, dextran-coated gold nanoparticles and glucose, and the interactions between dextran, glucose, and boronic-acid capped silver nanoparticles in solution. Our new approaches promise new tunable glucose sensing platforms. Dextran-coated gold nanoparticles were aggregated with the addition of Con A resulting in increase an in absorbance of nanoparticles at 650 nm, where the post-addition of glucose caused the dissociation of the aggregates and thus a decrease in the absorbance at 650 nm. The interaction of glucose and dextran with boronic acid-capped silver nanoparticles in solution resulted in enhanced luminescence intensity cumulatively due to surfaceenhanced fluorescence and the decrease in absorbance at 400 nm, with an increase in absorbance at 640 nm. Lifetime measurements were used to distinguish the contribution from the surface-enhanced fluorescence. TEM was employed to assess the aggregation of nanoparticles.

“…As a common medical condition that produces excessive thirst, continuous urination and severe weight loss, Diabetes 4 has interested medical researchers for over three millennia. Unfortunately it wasn't until the early 20th cen-tury that the prognosis for this condition became any better than it was 3000 years ago.…”

Section: Introductionmentioning

confidence: 99%

“…To this end, many technologies have been developed over the past 20 years in an attempt to provide a technology which promises both non-invasive and continuous physiological glucose monitoring. These include near infrared spectroscopy [3,4], optical rotation [5,6], colorimetric [7,8] and fluorescence detection [9][10][11][12][13], to name but just a very few. Recently we have seen the launch of the new GlucoWatch, which approved by the FDA in 2001, is the first step towards both the continuous and non-invasive monitoring of physiological glucose.…”

Section: Introductionmentioning

confidence: 99%

Ophthalmic Glucose Monitoring Using Disposable Contact Lenses—A Review

Badugu

Geddes

2004

We have developed a range of disposable and colorless tear glucose sensing contact lenses, using offthe-shelf lenses embedded with new water soluble, highly fluorescent and glucose sensitive boronic acid containing fluorophores. The new lenses are readily able to track tear glucose levels and therefore blood glucose levels, which are ideally suited for potential use by diabetics. The fluorescence responses from the lenses can be monitored using simple excitation and emission detection devices. The novelty of our approach is two fold. Firstly, the notion of sensing extremely low glucose concentrations in tears, which track blood levels, by our contact lens approach, and secondly, the unique compatibility of our new glucose signaling probes with the internal mildly acidic contact lens environment. The new lenses are therefore ideal for the non-invasive and continuous monitoring of tear glucose, with about 15-min response time, and a measured shelf life in excess of 3 months. In this review article, we show that fluorescence based signaling using plastic disposable lenses, which have already been industrially optimized with regard to vision correction and oxygen/analyte permeability etc, may a notable alternative to invasive and random finger pricking, the most widely used glucose monitoring technology by diabetics.