Soft contact lens biosensor for in situ monitoring of tear glucose as non-invasive blood sugar assessment.

A contact lens (CL) biosensor for in situ monitoring of tear glucose was fabricated and tested. Biocompatible 2-methacryloyloxyethyl phosphorylcholine (MPC) polymer and polydimethyl siloxane (PDMS) were employed as the biosensor material. The biosensor consists of a flexible Pt working electrode and a Ag/AgCl reference/counter electrode, which were formed by micro-electro-mechanical systems (MEMS) technique. The electrode at the sensing region was modified with glucose oxidase (GOD). The CL biosensor showed a good relationship between the output current and glucose concentration in a range of 0.03-5.0mM, with a correlation coefficient of 0.999. The calibration range covered the reported tear glucose concentrations in normal and diabetic patients. Also, the CL biosensor was applied to a rabbit for the purpose of tear glucose monitoring. The basal tear glucose was estimated to 0.11 mM. Also, the change of tear glucose induced by the change of blood sugar level was assessed by the oral glucose tolerance test. As a result, tear glucose level increased with a delay of 10 min from blood sugar level. The result showed that the CL biosensor is expected to provide further detailed information about the relationship between dynamics of blood glucose and tear glucose.

[1]  Justin T. Baca,et al.  Analysis of tear glucose concentration with electrospray ionization mass spectrometry , 2007, Journal of the American Society for Mass Spectrometry.

[2]  R. K. Shervedani,et al.  A novel method for glucose determination based on electrochemical impedance spectroscopy using glucose oxidase self-assembled biosensor. , 2006, Bioelectrochemistry.

[3]  G. S. Wilson,et al.  Elimination of the acetaminophen interference in an implantable glucose sensor. , 1994, Analytical chemistry.

[4]  G. W. Shaw,et al.  In vivo molecular sensing in diabetes mellitus: an implantable glucose sensor with direct electron transfer , 1989, Diabetologia.

[5]  P. Stephens,et al.  TEAR GLUCOSE IN DIABETICS* , 1958 .

[6]  Justin T. Baca,et al.  Mass spectral determination of fasting tear glucose concentrations in nondiabetic volunteers. , 2007, Clinical chemistry.

[7]  J. Pickup,et al.  Fluorescence-based sensing of glucose using engineered glucose/galactose-binding protein: a comparison of fluorescence resonance energy transfer and environmentally sensitive dye labelling strategies. , 2008, Biochemical and biophysical research communications.

[8]  Y. Yamasaki,et al.  Closed-Loop Glycemic Control with a Wearable Artificial Endocrine Pancreas Variations in Daily Insulin Requirements to Glycemic Response , 1984, Diabetes.

[9]  Vanesa Sanz,et al.  A blood-assisted optical biosensor for automatic glucose determination. , 2009, Talanta.

[10]  D. Gough,et al.  Development of the Implantable Glucose Sensor: What Are the Prospects and Why Is It Taking So Long? , 1995, Diabetes.

[11]  Mark S. Talary,et al.  In vivo life sign application of dielectric spectroscopy and non-invasive glucose monitoring , 2007 .

[12]  D K Sen,et al.  Tear glucose levels in normal people and in diabetic patients. , 1980, The British journal of ophthalmology.

[13]  L. Braverman,et al.  Tear glucose detection of hyperglycemia. , 1968, American journal of ophthalmology.

[14]  B. Zeng,et al.  Development of amperometric glucose biosensor through immobilizing enzyme in a Pt nanoparticles/mesoporous carbon matrix. , 2008, Talanta.

[15]  Joseph Wang,et al.  On-chip integration of enzyme and immunoassays: simultaneous measurements of insulin and glucose. , 2003, Journal of the American Chemical Society.

[16]  Taihong Wang,et al.  A novel amperometric biosensor based on NiO hollow nanospheres for biosensing glucose. , 2008, Talanta.

[17]  Emil Jovanov,et al.  Stress monitoring using a distributed wireless intelligent sensor system. , 2003, IEEE engineering in medicine and biology magazine : the quarterly magazine of the Engineering in Medicine & Biology Society.

[18]  Ingo Klimant,et al.  Miniaturized fiber-optic hybrid sensor for continuous glucose monitoring in subcutaneous tissue , 2007 .

[19]  Aleksandar Milenkovic,et al.  Wireless sensor networks for personal health monitoring: Issues and an implementation , 2006, Comput. Commun..

[20]  S. Wild,et al.  Global prevalence of diabetes: estimates for the year 2000 and projections for 2030. , 2004, Diabetes care.

[21]  A. Kijlstra,et al.  Inhibition of hydroxyl radical formation by human tears. , 1987, Investigative ophthalmology & visual science.

[22]  R. Sack,et al.  Tear Glucose Dynamics in Diabetes Mellitus , 2006, Current eye research.

[23]  R M Hill,et al.  Human tear glucose. , 1982, Investigative ophthalmology & visual science.

[24]  A. Giardini,et al.  Concentration of Glucose and Total Chloride in Tears * , 1950, The British journal of ophthalmology.

[25]  N. Evans,et al.  Fluorescence-based glucose sensors. , 2005, Biosensors & bioelectronics.

[26]  清水 康博,et al.  学会レポート The 12th International Conference on Solid-State Sensors, Actuators and Microsystems (TRANSDUCERS'03) , 2003 .

[27]  L. C. Clark,et al.  ELECTRODE SYSTEMS FOR CONTINUOUS MONITORING IN CARDIOVASCULAR SURGERY , 1962 .