The present invention relates to a microarray device for detecting a target molecule such as miRNA in a sample. The device comprises a carrier substrate such as glass, an anti-fouling polymer layer which is functionalised with N-Hydroxysuccinimide (NHS) or carboxyl-groups and a capture probe. In an embodiment, the capture probe is an oligonucleotide with a stem-loop structure. The invention further defines a method for fabricating the device, a kit for detecting the target nucleic acid molecule comprising the device and a detection probe.