Gold nanoparticles (AuNPs) possess unique physicochemical characteristics that can be crucial for the development of biosensors. 8-Oxo-2'-deoxyguanosine (8-oxo-dG) is a critical marker of DNA damage caused by oxidative stress and a risk factor for a variety of disorders, including cancer and neurodegenerative diseases. Current analytical approaches for detecting urinary 8-oxo-dG, such as ELISA, LC-MS/MS and HPLC equipped with electrochemical detection, are tedious and difficult to implement as a successful point-of-care testing (POCT). This work aimed to develop a rapid and easy-to-use colorimetric aptasensor for 8-oxo-dG detection in urine using cysteamine-stabilized AuNPs (Cyst-AuNPs) as color indicators and the 8-oxo-dG aptamer as a recognition component. The detection mechanism is based on the anti-aggregation of Cyst-AuNPs induced by the specific recognition of 8-oxo-dG and its aptamer, causing a visual change in color from red to purple, allowing for naked-eye detection. The limit of detection (LOD) for 8-oxo-dG is as low as 10.3 nM under the optimum conditions. The proposed approach was successfully used to determine the concentration of 8-oxo-dG in human urine. This rapid and simple-to-use technique may be used as alternative approach for developing a POCT strategy for monitoring DNA damage in urine.

Aptamer-gold nanoparticle-based colorimetric assays for DNA damage detection

ACS Spring 2022

The official archive and repository for all ACS Meetings & Expositions abstracts and select posters or presentations.