Polyelectrolyte microcapsules and coated CaCO3 particles as fluorescence activated sensors in flowmetry

Polyelectrolyte multilayer film capsules with different micrometer sizes were assembled for pH and salt sensing devices. Encapsulation of labelled poly(acrylic acid) (PAAAF) in CaCO3 particles increases their potential usage in the biological environment. Microcapsules were analyzed with flowcytometry to obtain individual response of a spherical-like microsensor that behaves as Donnan system. The linear pH response of microparticles and microcapsules is quite broad and is useful in physiological range. The salt response is up to 0.1 M and was also predicted with simple mathematical model.