Label-Free LSPR Prostate-Specific Antigen Immune-Sensor Based on GLAD-Fabricated Silver Nano-columns

Label-free detection of biomarkers has been recently noticed and optical biosensors showed great potential to be the method of choice in such situation. Here, we used glancing angle deposition (GLAD) method in which silver nano-columns stabilized by a self-assembled monolayer (SAM) of 11-mercaptoundecanoic acid (MUA) and 6-mercaptohexanol to investigate the capability of localized surface plasmon resonance (LSPR)–based silver nanochips to detect prostate-specific antigen (PSA). Using different standard solutions of PSA, limit of detection (LOD) of the nano-sensors has been calculated to be 850 pg/ml. The selectivity of the nano-sensors has also been evaluated. We showed that these nano-sensors could detect PSA in clinically acceptable sensitivity and specificity without any complicated laboratory equipment.