SERS encoded nanoparticle heterodimers for the ultrasensitive detection of folic acid

In this paper, gold–silver nanoparticle (AuNP–AgNP) heterodimers were assembled with highly yield as an active SERS substrate, based on antigen–antibody immunoreaction. The developed SERS sensor has successful achieved the ultrasensitive detection of folic acid (FA) with the limit of detection (LOD) as 0.86 pg/mL. And the linear range was from 0.005 ng/mL to 1 ng/mL. The results also demonstrated that this developed method showed high specificity and excellent recovery for the human serum samples, indicating its promising potential in bio-diagnosis and the environmental monitoring.