Ratio measurements in oxygen determinations: wavelength ratiometry, lifetime discrimination, and polarization detection

In this work we present ratiometric measurements of oxygen concentrations using a dual-emitting dye. Three different methods for ratio measurements in oxygen sensing are employed. The standard wavelength-ratiometric approach is simple to implement, but the sensor response has significant non-linearity. The frequency discrimination of the lifetimes allows for measurements of dual-emission ratio through a single emission filter. In this case the Stern–Volmer plots are linear. Another option is to use emission polarization.