Currently, patients with diabetes may choose between two major types of system for glucose measurement: blood glucose monitoring (BGM) systems measuring glucose within capillary blood and continuous glucose monitoring (CGM) systems measuring glucose within interstitial fluid. Although BGM and CGM systems offer different functionality, both types of system are intended to help users achieve improved glucose control. Another area in which BGM and CGM systems differ is measurement accuracy. In the literature, BGM system accuracy is assessed mainly according to ISO 15197:2013 accuracy requirements, whereas CGM accuracy has hitherto mainly been assessed by MARD, although often results from additional analyses such as bias analysis or error grid analysis are provided. The intention of this review is to provide a comparison of different approaches used to determine the accuracy of BGM and CGM systems and factors that should be considered when using these different measures of accuracy to make comparisons between the analytical performance (ie, accuracy) of BGM and CGM systems. In addition, real-world implications of accuracy and its relevance are discussed.

The biosensor field has grown enormously since the first demonstration of the biosensor concept by Leland C. Clark, Jr. in 1962. Today's biosensor market is dominated by glucose biosensors, mass-produced enzyme electrodes for the rapid self-diagnosis of blood glucose levels by diabetes sufferers. Here we take a historical look at the inception, growth, and development of the enzyme biosensor field from a commercial viewpoint. The current status of the technology is evaluated and future trends in this dynamic and fast-moving field are also anticipated.

Screen-printed three-electrode amperometric sensors incorporating L- and/or D-amino acid oxidase for the general purpose measurement of L- or D-amino acids is described. The working electrode incorporates rhodinized carbon, to facilitate hydrogen peroxide oxidation at a decreased operating potential, and immobilized enzyme. The devices responded to all 20 common L-amino acids and all of the D-amino acids examined, the exceptions being L- and D-proline. Linear response profiles were observed for L-leucine, L-glycine and L-phenylalanine with limits of detection of 0.47, 0.15 and 0.20 mM respectively. The devices were reproducible and exhibited stability over a 56 d test period. The biosensor compares favourably with a standard photometric amino acid test and was used to monitor milk ageing effects. The assay is cheap, simple to perform and rapid, requiring only buffer-electrolyte and a small sample volume.

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Vincent J Vezzaa, Adrian Butterwortha, Perrine Lasserrea, Ewen O Blaira, Alexander MacDonalda, Stuart Hannaha, Christopher Rinaldib, Paul A Hoskissonc, Andrew C Wardd, Alistair Longmuire, Steven Setforde, Eoghan CW Farmerf, Michael...