Abstract: A composition, test device, method of making a test device and process for determination of an analyte in a liquid sample are disclosed. More particularly, there is provided a composition for the determination of an analyte in a sample which composition comprises an analyte-responsive component comprising a pyridine nucleotide susceptible of reduction in response to the presence of said analyte and at least one constituent interreactive with said analyte to cause reduction of the pyridine nucleotide, an uncoupler effective to generate an oxidizing substance from the reduced form of said pyridine nucleotide, a peroxidatively active substance, and an indicator which, when oxidized, is not susceptible to reduction by said reduced pyridine nucleotide. The pyridine nucleotide can be nicotine adenine dinucleotide (NAD) or nicotine adenine dinucleotide phosphate (NADP).