The present invention relates to a method for fabricating a microneedle-based diagnostic skin patch coated with an aptamer, comprising treating a microneedle surface with base to modify the surface with carboxyl group and binding the carboxyl group of the surface with an aptamer with an amine group and an aptamer-coated, microneedle-based diagnostic skin patch thereby. A patch of the present invention has the advantage of attaching a great number of aptamers, which are much smaller in size than antibodies, onto a relatively great number of microneedle tip surfaces, Allowing the attachment of aptamers for various kinds of biomarkers all together thereto, the patch can also simultaneously detect various kinds of materials (multiplexing). Therefore, a microneedle tip-based skin patch can also be used as a protein chip using aptamer.
