A functional polymeric 3D device is produced in a single step printing process using a stereolithography based 3D printer. The photocurable formulation is designed for introducing a controlled amount of carboxyl groups (-COOH), in order to perform a covalent immobilization of bioreceptors on the device. The effectiveness of the application is demonstrated by performing an immunoassay for the detection of protein biomarkers involved in angiogenesis, whose role is crucial in the onset of cancer and in the progressive metastatic behavior of tumors. The detection of angiogenesis biomarkers is necessary for an early diagnosis of the pathology, allowing the employment of a less invasive therapy for the patient. In particular, vascular endothelial growth factor and angiopoietin-2 biomarkers are detected with a limit of detection of 11 ng mL-1 and 0.8 ng mL-1, respectively. This study shows how 3D microfabrication techniques, material characterization, and device development could be combined to obtain an engineered polymeric chip with intrinsic tuned functionalities.