Determination of enzymes activity is an important task of analytical and biomedical oriented fluorimetry. Despite of a long track record of application, there is still some room for improvements in this field. In the case of hydrolases , spontaneous decomposition of substrate leads to substantial errors in determination of enzyme activity. An innovative and effective approach is proposed allowing protection of enzyme substrate within the lipophilic moiety of polyacrylate microspheres. It is shown that the introduction of substrate into microspheres is not only an effective method of prevention of unwanted spontaneous process, but also does not disturb the availability of substrate for enzymatic hydrolysis. The effect of presence of proteins in the sample on fluorimetric responses was studied. In contrary to previous studies related to application of lipophilic polymers in biomedical analysis, it is shown that the presence of bovine serum albumins enhances the sensitivity of fluorimetric determination. It is shown that this surprising effect is related to adsorption of proteins on the microspheres surface and change of surface charge of polymer.
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