Flower-like GO-MoS2 SERS platform for sensitive quantification of cortisol

Abstract Mental stress is a dangerous factor for the health of living beings, which can lead to various diseases. However, currently, there is a lack of diagnostic tools that can quickly and accurately quantify levels of mental stress. Cortisol is an important stress hormone that is widely present in bodily fluids; its concentration can reflect the level of mental stress in organisms. Here, we report a surface-enhanced Raman spectroscopy (SERS) probe based on flower-like graphene oxide-molybdenum disulfide composite material functionalized with cortisol DNA recognition element and tetracyanoquinodimethane of Raman label, with a remarkable enhancement factor value of 7.38 × 10 5 , which exhibits excellent cortisol detection ability in a wide range of concentrations from 1 nM to 1 000 nM, with the limit of detection down to 0.773 nM. The whole detection takes only 20 min. In addition, the SERS probe can selectively detect cortisol in other substances with similar chemical structures, which makes the probe applicable to complex biological systems with good reproducibility and stability. This designed SERS probe has been successfully employed in the detection of mouse serum cortisol, with high accuracy compared with enzyme-linked immunosorbent assay (ELISA) results, demonstrating great potential in actual biological sample detection.