Methods for improving sensitivity of oxygen biosensors

A method for detecting oxygen consumption in a test sample comprising:

• exposing a test sample to a first sensor composition and a control sample to a second sensor composition, said first and second sensor composition comprising a luminescent compound being inhibited from generating a detectable signal in the presence of an inhibitory amount of oxygen and which generates a detectable signal as the inhibitory amount of oxygen is reduced;
• determining the strength of a first said detachable signals generated by said first sensor composition at time intervals;
• determining the strength of a second said detectable signal generated by said second sensor composition at said time intervals;
• comparing the strengths of said first signal with said second signal over said time intervals and determining whether oxygen in said test sample has been consumed wherein said comparing step comprises:
• normalizing said first said detectable signals and said second said detectable signals, said normalizing step comprising:
• dividing each said first said detectable signal by an initial said first said detectable signal;
• and
• dividing each said second said detectable signal by an initial said second said detectable signal;
• calculating the area between curves representative of said normalized first said detectable signals and said normalized said second said detectable signals;
• and
• comparing said area to zero.