A stable and sensitive 2D SERS sensor for bioanalytical applications

[Display omitted] •A sensitive and stable SERS sensor based on gold nanospheres deposition.•SEM and AFM analysis of the sensor surface highlights optimum surface morphology.•High SERS activity: Enhancement Factor = 2.3⨯108.•Well suited for the Therapeutic Drug Monitoring of anticancer agents.•Reliable quantitative analysis in a concentration range of clinical interest. In this study, we describe a 2D-SERS sensor obtained by deposition of spherical gold nanoparticles (AuNPs) onto a suitably functionalized metal surface. Morphological analysis of the SERS surface by SEM and AFM demonstrated a uniform and stable distribution of the active nanoparticles. Following p-mercaptoaniline (pMA) functionalization, the sensor was characterized by co-localized Raman measurements, demonstrating a significant enhancement in Raman signals with homogeneous SERS activity across the entire sampled area. The as-prepared SERS sensor was demonstrated to be suitable for Therapeutic Drug Monitoring (TDM) of 6-mercaptopurine (6-MP), exhibiting a linear correlation between analyte concentration and SERS intensity in the range 5 – 20 μM. This work highlights the potential of 2D-SERS sensors for hypersensitive and accurate analytical measurements, particularly in the biomedical field.