the present invention relates to novel methods for the diagnosis of helicobacter pylori infection . specifically , the present invention relates to novel non - invasive methods for the detection of the presence or absence of a helicobacter pylori antigen or a metabolite produced by the bacterium in a biological sample with a biosensor - based measurement . the present invention also related to the use of a biosensor containing specific antibodies against h . pylori or antigen - binding fragments thereof immobilized thereto together with bio - molecule - repellent polymers preventing the non - specific binding . the invention also relates to test kits useful in the methods .