Abstract: A microfluidic reactor arrangement (100) for use in detecting an analyte in a fluid sample (106) is described. The reactor arrangement is provided with a reagent providing means such that the reagent can be introduced after assembly of the reactor arrangement. The latter can be performed by introducing the reagent in the form of a solution or a dispersion and fixing it on a holding means (118) by removal of the liquid, i.e. by drying, the holding means comprising the reagent in a solid version in the detector chamber. Prior to the introduction of the reagent, components of the reactor arrangement already present, such as the sample inlet can be hydrophilised by a wetting hydrophilising technique. The invention relates to a manufacturing technique as well as to the resulting product. The invention furthermore relates to functionalizing of the reactor arrangement with a particular reagent for particular applications.