Blood-glucose biosensor

Wang, J. Macca, C. Use of Blood-Glucose Test Strips for Introducing Enzyme Electrodes and Modern Biosensors, ... 

Commercially available kits for monitoring blood-glucose use an amperometric biosensor incorporating the enzyme glucose oxidase. This experiment describes how such monitors can be adapted to the quantitative analysis of glucose in beverages. 

FIGURE 3.4 A typical commercial strip for self-testing of blood glucose (based on a biosensor manufactured by Abbott Inc.) (see Plate 1 for the color version). 

J.D. Newman and A.P.F. Turner, Home blood glucose biosensors a commercial prospective. Biosensors and Bioelectronics 20, 2388-2403 (2005). 

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. 

J. Risley,/. Chem. Educ. 68,1054 (1991). Preparing Solutions in the Biochemistry Lab. J. Wang and C. Macca,/. Chem. Educ. 73, 797 (1996). Use of Blood-Glucose Strips for Introducing Enzyme Electrodes and Modern Biosensors. ... 

Biosensors for the determination of blood glucose have enjoyed widespread commercial success since the introduction of the pen-sized 30 s blood glucose meter [10]. However, researchers have continued to devise novel approaches in the development of amperometric biosensors based on screen-printing technology Table 23.1 summarises some examples of these approaches together with their performance characteristics. 

N.J. Forrow and S.W. Bayliff, A commercial whole blood glucose biosensor with a low sensitivity to hematocrit based on an impregnated porous carbon electrode, Biosens. Bioelectron., 21 (2005) 581-587. 

Before dealing with the central topic, I would like to raise some further issues pertinent to it, and indeed to the development of thick-film sensors in general. Thick-film sensors are an important part of biosensor research because some blood glucose sensors for use in the home are made this way—if these are successful surely others can be Further, thick-film technology is not expensive and allows research laboratories to produce quickly, reasonably uniform devices in sufficient numbers for well replicated experiments. At the same time, some insight can be gained into the nature and demands of an industrial production process. 

Biosensors with their oft-quoted (ideal) properties would seem to be ready partners for industrial analysts who want information at point-of-need, but as has been pointed out many times, few examples have had the same success as the blood glucose sensors for use in the home (albeit this is an example from medicine rather than industry). The reasons for this have also been pointed out many times, the principal one being that the development and manufacture of the blood glucose sensors is supported by the sadly huge market for diabetic testing and the large amount of investment capital which accrues to that market [6,7]. Further, blood is a sample of reasonably constant composition (in this context), the information is truly useful to the client and the desire for information at home means there is less competition from laboratory-based instruments. This is in contrast to the diverse requirements for analysis in the food industry (for example) which make up a series of... 

Lee et al. [62] have demonstrated lately the possibility to quantify glucose concentrations in interstitial fluid (ISF) by an electrochemical biosensor after permeability enhancement with a 20 min light cymbal ultrasound array (37 x 37 x 7 mm3, 22 g, 20 kHz, and 100 mW/cm2). The authors present a good correlation to blood glucose concentrations in hyperglycemic rats. 

Figure 3.2 The effect of prolonged subcutaneous implantation on biosensor function. Blood glucose values shown in solid circles and glucose sensor values in the continuous lines. The early study (top panel), but not the late study (bottom), shows excellent sensor accuracy and minimal lag between blood glucose and sensed glucose values. MARD (mean absolute relative difference) refers to a sensor accuracy metric. EGA refers to the Clarke error grid analysis accuracy metric.

Kimura J. Noninvasive blood glucose concentration monitoring method with suction effusion fluid by ISFET biosensor. Applied Biochemistry and Biotechnology 1993, 41, 55-58. 

The most important and most studied applications of enzyme biosensors are to detect and monitor blood glucose, followed by lactate, because of the medical applications of such sensors. Thus, by initially detailing the development of glucose biosensors we can better understand and trace the general development of enzyme biosensors containing polymeric electron transfer systems. 

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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