Electrochemical glucose biosensors - Electrochemical Sensors, Biosensors and Their Biomedical Applications - page 63

B

A

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

TABLE 3.2
Major commercial electrochemical systems for self-monitoring of blood glucose

Source Trade name Enzyme Mediator

Abbott Precision GOx Ferrocene

FreeStyle GOx Osmium “wire”

Bayer Elite GOx Ferricyanide

LifeScan SureStep GOx Ferricyanide

One Touch Ultra GOx

Roche-Diagnostics Accu-Check GOx Ferricyanide

The control meter is typically light and small (pocket size), battery operated, and
relies on a potential-step (chronoamperometric) operation, in connection with a
short incubation (reaction) step. Such devices offer considerable promise for obtain-
ing the desired clinical information in a simpler (“user-friendly”), faster, and cheaper
manner compared to traditional assays. The fi rst product was a pen-style device (the
Exactech™), launched by Medisense Inc. in 1987, that relied on the use of a ferrocene-
derivative mediator. Since then, over 40 different commercial strips and pocket-sized
test meters, for self-monitoring of blood glucose - based on the use of ferricyanide or
ferrocene mediators - have been introduced [32]. Yet, over 90% of the market is being
shared by Life Scan, Roche Diagnostics, Abbott, and Bayer (Table 3.2). In all cases, the
diabetic patient pricks the fi nger, places the small blood droplet on the sensor strip, and
obtains the blood glucose concentration (on an LC display) within 5-30 sec. In addi-
tion to fast response and small size, such modern personal glucose meters have features
such as extended memory capacity and computer downloading capabilities.