Early prostate cancer (PCa) diagnostic is crucial to enhance patient survival rates; besides, non-invasive platforms have been developed worldwide in order to precisely detect PCa biomarkers. Therefore, the aim of the present study is to develop a new aptamer-based biosensor through the self-assembling of thiolated aptamers for PSA and VEGF on the top of gold electrodes. This biosensor was tested in three prostate cell lines (RWPE-1, LNCaP and PC3). The results evidenced a stable and sensitive sensor presenting wide linear detection ranges (0.08-100 ng/mL for PSA and 0.15 ng-100 ng/mL for VEGF). Therefore, the aptasensor was able to detect the patterns of PSA and VEGF released in vitro by PCa cells, which gave new insights about the prostate cancer protein dynamics. Thus, it could be used as a non-invasive PCa clinical diagnosis instrument in the near future. Graphical Abstract Overview of the experimental design applied to the aptamer-based electrochemical sensor self-assembled on the thiolated hairpin structure. A filter membrane was added on top of working electrode to provide the cell-attachment surface after aptamer incubation, without compromising the aptamer layer. The pore membrane allowed target proteins to pass to the aptamer surface; the MCH backfilling avoided unspecific protein binding to the gold electrode surface.

Electrochemical aptasensors can detect cancer biomarkers such as mucin 1 (MUC1) to provide point‐of‐care diagnosis that is low‐cost, specific and sensitive. Herein, a DNA hairpin containing MUC1 aptamer was thiolated, conjugated with methylene blue (MB) redox tag, and immobilized on a gold electrode by self‐assembly. The fabrication process was characterized by scanning electron microscopy, X‐ray spectroscopy analysis and electrochemistry techniques. The results evidenced a stable and sensitivity sensor presenting wide linear detection range (0.65–110 ng/mL). Therefore, it was able to precisely detect MUC1 production patterns in normal (RWPE‐1) and prostate cancer cells (LNCaP and PC3). The biosensor has ability to detect MUC1 in complex samples being an efficient and useful platform for cancer diagnosing in early stages and for physiological applications such as cancer treatment monitoring.