. Author manuscript; available in PMC: 2011 Mar 18.

Published in final edited form as: Lab Chip. 2010 Oct 7;10(22):3163–3169. doi: 10.1039/c0lc00237b

Table 2.

Glucometers as electrochemical readers for amperometric detection in EμPADs

Analyte	Enzyme	Electron-transfer mediator	Dynamic linear range	Limit of detection	Notes
Glucose	Glucose oxidase	Ferricyanide	0–500 mg dL⁻¹	26 mg dL⁻¹	Pre-stored^a
Ethanol	Alcohol dehydrogenase/β-NAD⁺	Ferricyanide	0.1–3 mM	0.2 mM	Pre-stored
Cholesterol	Cholesterol oxidase	Ferricyanide	20–200 mg dL⁻¹	13 mg dL⁻¹	Pre-mixed^b
l-Lactate	Lactate oxidase	Ferricyanide	1.1–11 mM	1.1 mM^c	Pre-mixed

Pre-stored: we stored chemical reagents needed for the assay on the EμPAD, and carried out the assay with the EμPAD in glucometer.

Pre-mixed: we mixed chemical reagents needed for the assay with a solution containing analytes, and allowed the reaction to proceed to completion off the EμPAD. The glucometer was used simply as an amperometer to read the result.

The commercially available human plasma itself contains 1.1 mM lactate before the addition of any lactate. In fact, we were able to detect 0.5 mM of lactate in PBS buffer solution (pH 7.0).