Detection of circulating prostate cancer cells via prostate specific membrane antigen by chronoimpedimetric aptasensor

Abstract

Objectives: Sensitive and accurate techniques for early detection of prostate cancer, which has a good chance for successful treatment if detected early, are of utmost value. Our aim is to develop a sensitive chronoimpedimetric biosensor for detection of circulating prostatic tumor cells (CTCs) with an aptamer selective for prostate specific membrane antigen (PSMA). Methods: Thiolated PSMA-specific aptamer was immobilized on the gold nanoparticle modified carbon screen-printed electrodes. After characterization with cyclic voltammetry and electrochemical impedance spectrometry, scanning electron microscopy and atomic force microscopy studies were conducted to confirm the modifications. LNCaP cells (androgen-sensitive human prostate adenocarcinoma cells), were then added to the serum samples and chronoimpedimetric detection of CTCs in samples were performed. Results: Our study showed one cell detection capability in real serum samples with a linear range from 1 to 40 cells/ mL. The incubation time was 130 s. LOD was found to be 0.62 cells/mL and relative standard deviations were lower than 2% RSD. Reproducibility tests indicated a regression coefficient as R2 = 0.9963 ± 0.0178. Conclusions: This new biosensor enables rapid, accurate, precise, reproducible and highly sensitive detection of PSMA on CTCs in prostate cancer and paves the way to new diagnostic applications and research-based studies.