The present invention relates to a method for capturing a molecular target present in the aqueous phase of a water-in-oil emulsion, said method being based on the use of a binding system comprising (a) a surfactant bearing a functional moiety on its hydrophilic head group and (b) a chemoprobe that acts as a molecular staple between the functionalized surfactant and the molecular target and comprises at least two distinct domains namely (i) at least one capture moiety which is able to specifically bind the molecular target and (ii) at least one binding domain which is able to interact with the functional group of the surfactant through covalent or non-covalent interactions, directly or through a binding intermediary.