Optical Glucose Sensor Yonathan Essaw Outline • • • • • • • • Explain Diabetes Treatment Problem Optical Glucose Sensors Fluorescence (luminescence) Boronic Acid Reaction Mechanism Conclusion and future research What is Diabetes? • Diabetes is a chronic disease that affects the body's ability to produce or respond to insulin, the hormone that allows glucose to enter the body's cells and be stored or used for energy. • Many diabetics require insulin injections, and all must carefully monitor and manage their blood glucose levels. http://currents.ucsc.edu/03-04/03-15/glucose.html Type of Diabities Type 1 diabetes • Juvenile diabetes or insulin-dependent diabetes • first diagnosed in children, teenagers, or young adults. • the beta cells of the pancreas no longer make insulin because the body's immune system has attacked and destroyed them •http://diabetes.niddk.nih.gov/dm/pubs/type1and2/what.htm Type 2 diabetes • Adult-onset diabetes or noninsulin-dependent diabetes • usually begins with insulin resistance, a condition in which fat, muscle, and liver cells do not use insulin properly • Being overweight and inactive increases the chances of developing type 2 diabetes. Treatment Type 1 diabetes • Treatment for type 1 diabetes includes taking insulin shots or using an insulin pump, making wise food choices, being physically active, taking aspirin daily (for some), and controlling blood pressure and cholesterol. http://diabetes.niddk.nih.gov/dm/pubs/type1and2/what.htm Type 2 diabetes • Treatment for type 2 diabetes includes using diabetes medicines, making wise food choices, being physically active, taking aspirin daily, and controlling blood pressure and cholesterol. Problem • For millions of diabetics, this means drawing blood several times a day, usually from finger pricks. But glucose levels can fluctuate widely throughout the day, making it difficult to know when to do the blood tests for optimal control of glucose levels. • A device, such as the optical glucose sensor, that can provide continuous monitoring of blood sugar would sharply reduce the risk of long term complications, which includes blindness, hearth attack, and kidney failures. http://www.medicalnewstoday.com/index.php?newsid=6673 Optical Glucose Sensor • A Glucose sensor is designed to automatically measure interstitial sugar every few minutes, without any user intervention. http://www.mendosa.com/third_generation.htm Main Idea • The Idea is that as the intensity of fluorescence varies, information is transmitted through radio waves by an implanted device equipped with both light source and a photodetector. • Then the waves would be received by another device worn outside the body, and information regarding the individual’s glucose level would trigger an alarm. Optical Glucose Sensor • Glucose sensor uses a hydrogel—a polymer similar to contact lenses, that is permeable to glucose. • A Fluorescent chemical compound is contained within a hydogel polymer for stabilization inside the body. • The Hydrogel has multiple functionalities as a enzyme reservoir and a skin sensor, and maintaining osmotic gradient for glucose extraction form the skin. http://www.sontra.com/pdfs/glumonihumanclinicalres_pres@diabtechmeetingoct2004.pdf Optical Glucose Sensor • The hydrogel polymer can be placed under the skin or in a major blood vessel. Along with th fluorescent dye, the sensor contains a molecule, called a “quencher.” • Quencher acts as a kind of switch for the dye. In the absence of glucose, the quencher binds to the dye and prevents fluorescence. When glucose is present, the light shines brighter. http://www.osa-opn.org/view_file.cfm?doc=%24)%3C3%2FJ0%20%20%0A&id=%24*%2C%23'J%20%20%20%0A Fluorescence luminescence • (luminescence) A molecule absorbs a high-energy photon, and re-emits it as a lower-energy (longerwavelength) photon. The energy difference between the absorbed and emitted photons ends up as molecular vibrations (heat). http://www.absoluteastronomy.com/encyclopedia/f/fl/fluorescence.htm Fluorescence & Sensors • Fluorescence is a very sensitive technique, it is possible to detect single molecules. Fluorescent sensors for saccharides have been developed based on the interaction between a boronic acid and a diol. • Fluorescent sensors based on the Lewis acid-base interaction between a boronic acid and fluoride ions have been devised. http://www.bath.ac.uk/chemistry/james/ Color changes • The picture shows the visible color change observed on the addition of Dglucose to a solution of a boronic acid azo dye molecule http://www.bath.ac.uk/chemistry/james/ Boronic acid • Boronic acid is a chemical compound that binds to sugar. “We decided to go with a light source (fluorescence), because light is very sensitive. There are instruments that can measure one single photon,” Singaram a researcher at UCSC said. Boronic Acid • Laboratories around the country have been experimenting on Boronic acidbased, optical glucose sensor using fluorescence as a detection method. • The use of the boronic acids as chelator groups for monosacharides has attracted increasing attention for the development of alternative approach in glucose monitoring . http://www.osa-opn.org/view_file.cfm?doc=%24)%3C3%2FJ0%20%20%0A&id=%24*%2C%23'J%20%20%20%0A Typically Used Systems 9-[[N-Methyl-N-(o-boronobenzyl)amino]methyl]anthracene 9,10-Bis[ [N-methyl-N-(o- boronobenzyl)amino]methyl] anthracene file:///C:/Documents%20and%20Settings/libstu.SJCC_STU.001/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/8HST656D/275,7,Slide 7 Basic Mechanism Reaction Mechanism file:///C:/Documents%20and%20Settings/libstu.SJCC_STU.001/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/8HST656D/275,7,Slide 7 Reaction Mechanism Mechanism file:///C:/Documents%20and%20Settings/libstu.SJCC_STU.001/Local%20Settings/Temporary%20Internet%20Files/Content.IE5/8HST656D/275,7,Slide 7 9,10-Bis[ [N-methyl-N-(o- boronobenzyl)amino]methyl] anthracene Conclusion • It is extremely important for humans to find ways of treatment for diabetes. • An Instrument such as the Optical Glucose Sensors will make great impact on the fight against diabetes. • Boronic acids based fluorescence sugar sensors can be designed selectively for glucose. Further Research • Current research is directed towards the synthesis of thin film polymers that contain the sensing components for longer term stability. http://www.chemistry.ucsc.edu/~singaram/research%20files/Optical%20Glucose.htm Bibliography • • • • • • • • • • http://edcp.org/factsheets/aids.htmlhttp://chemistry.about.com/library/weekly/aa031703a.htm http://www.chem.sc.edu/faculty/wang/overview.html http://pubs.acs.org/subscribe/journals/mdd/v05/i05/html/05news3.html http://www.chemistry.ucsc.edu/~singaram/research%20files/Optical%20Glucose.htm http://cfs.umbi.umd.edu/cfs/reprints/New%20Color%20Chemosensors.pdf#search='boronic%2 0acid%20sensors%20Diabetes‘ http://diabetes.niddk.nih.gov/dm/pubs/type1and2/what.htm http://www.betterhumans.com/Errors/index.aspx?aspxerrorpath=/Glowing_Sensor_May_Allow_ Artificial_Pancreas.Article.2004-03-17-3.aspx http://cfs.umbi.umd.edu/cfs/reprints/New%20Color%20Chemosensors.pdf http://www.bath.ac.uk/chemistry/james/ file:///C:/Documents%20and%20Settings/libstu.SJCC_STU.001/Local%20Settings/Temporary %20Internet%20Files/Content.IE5/8HST656D/269,23,Slide 23 Yehaaaaaa……am done Thank You