Metal-organic framework modified by silver nanoparticles for SERS-based determination of sildenafil and pioglitazone...

A versatile surface-enhanced Raman scattering (SERS) assay has been established that can realize rapid and sensitive determination of sildenafil (SIL) and pioglitazone hydrochloride (PIO) adulteration in healthcare products. Metal-organic frameworks-silver nanoparticles (MOFs-AgNPs) with SERS activity were successfully prepared via in situ synthesis AgNPs on the MOFs surface. By virtue of the adsorptivity of MOFs, the MOFs-AgNPs could effectively concentrate the drug molecules on the electromagnetic enhancement areas of AgNPs. Moreover, the MOFs-AgNPs substrate exhibited more sensitive SERS activity than classical AgNPs with linear range of 1.0 × 10^-7-1.0 × 10^-5 mol L^-1 for SIL and 8.0 × 10^-7-3.0 × 10^-5 mol L^-1 for PIO and limit of detection (LOD) of 4.8 × 10^-8 mol L^-1 for SIL and 1.4 × 10^-7 mol L^-1 for PIO. The designed method realized the determination of SIL and PIO in commercial tablets and healthcare products with recoveries of 93.8-108.0% and 93.0-104.0%, respectively, with relative standard deviation (RSD) of 2.7-4.1% and 2.2-4.2%, respectively. The present system displayed little interference effect on determination. This work provides a multifunctional route for the determination of other drugs via the SERS technology.