Glucose, biosensors diabetes

Yu B, Ju Y, West L, Moussy Y, Moussy F (2007) An investigation of long-term performance of minimally invasive glucose biosensors. Diabetes Technol Ther 9 265-275... 

The material is presented in 17 chapters, covering topics such as trends in ion selective electrodes, advances in electrochemical immunosensors, modem glucose biosensors for diabetes management, biosensors based on nanomaterials (e.g. nanotubes or nanocrystals), biosensors for nitric oxide and superoxide, or biosensors for pesticides. 

Biosensors are analytical devices that incorporate a biological component and a transducer. These must be in close proximity with one another and preferably in intimate contact, i.e. the biological component immobilized on to the transducer. Such devices are available in disposable forms, e.g. for measurement of blood glucose in diabetic patients, evaluation of the freshness of uncooked meat. Other designs are suitable for continuous use, e.g. on-line monitoring of fermentation processes, the detection of toxic substances. 

For this reason, in the last decade, inorganic electrochemical mediators, which catalyse the oxidation or reduction of H202 have been preferred to HRP and have been used for the assembling of oxidase-based biosensors [18-20]. This results in a decrease of the applied potential and the consequent avoidance of electrochemical interferences. Many electrochemical mediators have been used and many of them have found broad application, especially in glucose biosensors for diabetes control. However, due to the solubility of the mediator, they are generally employed in a single-use sensor and present some problems due to the low operative stability. 

In recent years, the use of a microdialysis probe coupled on-line with a glucose biosensor has provided very good results for the continuous monitoring of glucose in diabetic patients [51-54],... 

Their biosensor consisted in a Pt wire on which GOD was immobilized by the electropolymerization of m-phenylenediamine. The advantage of this type of immobilization consists in creating an effective barrier against electrochemical interference due to the polymer formed onto the electrode. Moreover, an extended linearity for the glucose sensor was also obtained, and this was a requisite for the direct measurement of the subcutaneous glucose at diabetic levels, since in practice an extremely low dilution of the subcutaneous fluid was realized. 

Diabetes is a worldwide problem afflicting approximately 5% of the adult population of industrialized nations. In the USA 18.2 million people (13 million diagnosed, 5.2 million undiagnosed), approximately 6% of the US population is afflicted with diabetes. Over 40% of the population with diabetes is age 60 or older and 90-95% of all diagnosed cases of diabetes are type II diabetes (non-insulin dependent diabetes mellitus or adult-onset diabetes) [28]. There is a great need to develop the best possible glucose biosensors to continuously, accurately, painlessly and safely monitor blood glucose level to improve the lives of all diabetics. 

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