6 Summary and future direction

The glucose sensing industry is primarily driven by the diabetes epidemic. The number of people diagnosed with diabetes in UK has more than doubled from 1.4 m in 1996 to 2.9 m in 2011, and is expected to cross 5 m by 2025 (Diabetes UK, 2013). Similarly, diabetes prevalence worldwide of 366 m in 2011 is expected to increase to 552 m by 2030 [287–289]. The long-standing goal for reliable continuous glucose monitoring is still unmet, the finger-prick home glucose monitoring devices are indicated as acceptable with an error margin of ±20%, and laboratory testing is still the gold standard for diabetes diagnosis. Nanomaterials have an important role in making glucose sensing technologies cross the frontiers of traditional electrochemical and optical methods through solving the problems with large error margins and reliable in vivo lifetime and function of implantable glucose biosensors. In addition, the need for glucose sensing is also rapidly increasing in food, cell culture and biotechnology industries that help sustain the growing human population.