Patent ID: 8618293

Claim:
A method for measuring an amount or concentration of an analyte, comprising: (a) contacting a sample which contains the analyte with a solution containing an enzyme that acts on the analyte and a redox mediator of Formula I [M(A) w (B) x (C) y ] m (X z ) n Formula I wherein M is ruthenium or osmium and has an oxidation state of 0, 1, 2, 3 or 4; each of w, x, and y is an integer independently selected from the integers 1 to 4; m is an integer selected from the integers âˆ’5 to +4; n is an integer selected from selected from the integers 1 to 5; z is an integer selected from the integers âˆ’2 to +1; A is a monodentate 5- or 6-membered aromatic ligand containing 1, 2 or 3 nitrogen atoms which is optionally substituted by 1 to 8 substituents each selected from the group consisting of substituted or unsubstituted alkyl, alkenyl, or aryl groups, â€”F, â€”Cl, â€”Br, â€”I, â€”NO 2 , â€”CN, â€”CO 2 H, â€”SO 3 H, â€”NHNH 2 , â€”SH, aryl, alkoxycarbonyl, alkylaminocarbonyl, dialkylaminocarbonyl, â€”OH, alkoxy, â€”NH 2 , alkylamino, dialkylamino, alkanoylamino, arylcarboxamido, hydrazino, alkylhydrazino, hydroxylamino, alkoxyamino and alkylthio or A is NCS; B is a bi-, tri-, tetra-, penta- or hexadentate ligand which is linear having the formula R 1 RN(C 2 H 4 NR) w R 1 or cyclic having the formula (RNC 2 H 4 ) v , (RNC 2 H 4 ) p (RNC 3 H 6 ) q or [(RNC 2 H 4 )(RNC 3 H 6 )] s , wherein w is an integer selected from the integers 1-5, v is an integer selected from the integers 3-6, each of p and q is an integer independently selected from the integers 1-3 whereby the sum of p and q is 4, 5 or 6, s is either 2 or 3; and each of R and R 1 is independently hydrogen or alkyl; C is a ligand other than B; and X is a counter ion, wherein the number of coordinating atoms is 6, with the exception of [Ru III (Me 3 tacn)(acac)(py)](NO 3 ) 2 ); (b) incubating the contacted sample under conditions that cause the enzyme to act on the analyte; (c) subjecting the incubated sample of step (b) to conditions which result in a change in a measurable signal; and (d) measuring the measurable signal to determine the amount or concentration of the analyte in the sample.