Surface-Enhanced Raman Scattering Spectra of Non-Fluorescent 4-Mercaptobenzoic Acid and Human Red Blood Cells on Carnation-Shaped Silver Meso-Flowers Monolayer

Abstract

The development of new surface-enhanced Raman scattering (SERS) substrates is primarily motivated by designing synthetic substrates to obtain the significant signal enhancement. In this paper, a large-scale carnation-shaped Ag meso-flowers monolayer with sufficient “hot spots” has been synthesized on copper foil without using any capping agent. In dimethyl sulfoxide, AgNO3 is reduced by Cu for 60 min at 35 °C through the galvanic displacement reaction, and carnation-shaped Ag meso-flowers with good crystallinity and high purity are obtained. The as-fabricated carnation-shaped Ag meso-flowers monolayer is used as novel SERS substrates. Non-fluorescent 4-mercaptobenzoic acid is selected as the probe molecule to test the SERS activity, uniformity and enhancement factors (EF) of the monolayer. Experimental results show that the EF of the carnation-shaped Ag meso-flowers monolayer is up to 7.06×108 and the limit of detection is 10-11 M. Meanwhile, the biocompatibility of the carnation-shaped silver meso-flowers monolayer is tested for red blood cells detection. SERS measurements demonstrate that the carnation-shaped silver meso-flowers monolayer has good activity, uniformity and biocompatibility, and can be used as an outstanding SERS substrate, which has a broad application prospect in numerous chemical and biochemical sensing applications.