Detection of lipase activity with liquid foams

In this study, we present a new method for the detection of lipase. Lipase is an enzyme used as biomarker to monitor medical conditions like pancreatitis or to show the presence of biofilms. Traditionally, detecting lipase required specialized labs and equipment for which one has limited access, especially in less developed regions. Our detection method is based on changes in foam production of lipase-responsive foaming surfactant. Upon addition of the lipase, the ester-linkage of the lipase-responsive surfactant is cleaved which transforms the initially good foaming surfactant into non-foaming molecules so that no foam can be produced anymore. The read-out mechanism for the detection of lipase is the disappearance of foam production by mechanical agitation, i.e., there is a direct link between foam production and lipase activity. Our liquid foam detection method has distinct advantages compared to traditional methods, as it eliminates the need for specialized equipment or the use of markers like fluorescence: the change of foam production is detected directly by naked eyes. The method described here has the potential to be used as a simple fast screening method and to be combined with highthroughput readout systems.