VEGFA and neoplasm: Tumor organoids are arrayed on an antibody-functionalized plasmonic gold nanohole array. Secretion of VEGF-A is measured in real time under hypoxic conditions and chemotherapeutic drug treatment. LOD of 157 pg/mL.* Detection wells are separated from organoid laterally by 70 μm by a micropillar array since cells directly on top of the nanohole array will greatly affect the plasmonic signal.