Peroxidase-dependent fluorescence decrease of carboxyfluorescein and its enhancement by liposome encapsulation

The fluorescence intensity of 5(6)-carboxyfluorescein (CF) was decreased by addition of horseradish peroxidase (HRP) and hydrogen peroxide (H₂O₂). The reaction inside a liposome containing CF and HRP on addition of H₂O₂ was measured fluorometrically after destruction of the liposome with Triton X-100. The reaction efficiency was higher than that without liposome because CF and HRP were concentrated inside the latter. The determination of H₂O₂ can be performed with a smaller amount of HRP by liposome encapsulation.