© 2020 Elsevier B.V.A sensitive and selective, aptamer and spectroscopic ellipsometry based sensor is reported here for the early diagnosis of breast cancer, which is a common type of cancer following lung cancer. It was aimed to develop a single-step and label-free assay for the sensitive and selective detection of VEGF165. To this end, two different aptamers and spectroscopic ellipsometry were used. In the presented study, by determining the appropriate aptamer immobilization conditions, the spectroscopic ellipsometry technique was successfully applied for the detection of VEGF165 at the range of 1 pM–1000 pM in the buffer. Aptasensors have a detection limit of 5.81 pM and 4.29 pM, respectively.