Diabetes mellitus is a metabolic disease characterized by hyperglycemia or hypoglycemia resulting from defects in insulin secretion, action, or both (American Diabetes Association, 2010). In 2011, the prevalence of Americans with diabetes was estimated to be 25.8 million or 8.3% of the population. If present trends continue, it is predicted that as many as 1 in 3 American adults with have been diagnosed with diabetes by 2050 (American Diabetes Association, 2014). In 2012, the worldwide health problem cost diagnosed patients in the United States $245 billion in 2012. The worldwide commercial market for biosensors is predicted to reach $12 billion by 2015. Importantly, glucose biosensors account for up to 90% of the world market for universal biosensors (Global Industry Analysts, Inc., 2011). Therefore, careful consideration of their chemical application and distinctive parts are the main subject of this paper.
The emergence of the glucose biosensor was a historical landmark in the diagnosis of diabetes. The first glucose biosensor was publicly proposed by Professor Leland C. Clark Jr. in 1962 at New York Academy of Sciences symposium. His particular research described “how to make electrochemical sensors more intelligent by adding enzyme transducers as membrane enclosed sandwiches” (Clark et al., 1962). The first successful glucose biosensor was termed “Model 23A YSI analyzer” developed by the Yellow Springs Instrument Company in 1975. It was typically only used by professionals and hospitals as the cost of equipment to operate and analyze exceeded $20,000 (Rypins et al., 1985). By 2000, a more non-invasive method was introduced through the invention of the GlucoWatch® Biographer. The wearable glucose monitor extracted glucose through intact skin by employing a process called iontophoresis (Silverman et al., 2005). The standard price of $872.50 was reduced to $300 in 2004 before being taken off the market in 2008.
The universal glucose biosensor is characterized by three main parts: a bioreceptor able to recognize a molecular event, electrochemical enzyme transducer, and conversion of electrical signals into readable form. The bioreceptor includes molecular recognition elements such as receptors, enzymes, antibodies, or lectins able to differentiate between biomolecules. Types of transducers which convert biomolecule recognition event into a measurable signal include the following: electrochemical, optical, thermometric, piezoelectric, and magnet (Newman et al., 1992). For the purpose of this paper, an enzymatic amperometric glucose biosensor will be considered and more closely examined. As such, glucose biosensors employing the electrochemical amperometric sensor technique are the most commercially available due to better sensitivity, reproducibility, easy maintenance, and low cost.
Enzymatic amperometric glucose biosensors employ enzyme based electrodes for the measurement of glucose. The three most...