Improving SERS Activity of Inositol Hexaphosphate Capped Silver Nanoparticles: Fe³⁺ as a Switcher

Abstract

Inositol hexaphosphate (IP6) capped silver nanoparticles (IP6@AgNPs) were fabricated as surface-enhanced Raman scattering (SERS) active substrates. SERS activity of IP6@AgNPs could be further improved via adding due amounts of Fe(3+) to form Fe(3+)-IP6@AgNPs. The mechanism of Fe(3+)-induced SERS improvement of IP6@AgNPs can be attributed to the strong interaction of IP6 and Fe(3+), which leads to controllable adjustment of the gap among neighboring nanoparticles to produce "hot spots". The above mechanism was confirmed with ultraviolet-visible (UV-vis) spectroscopy, transmission electron microscope (TEM), dynamic light scattering (DLS), Fourier transform infrared (FT-IR) spectroscopy, and X-ray photoelectron spectroscopy (XPS). Such Fe(3+)-IP6@AgNPs-based SERS system was used to detect Rhodamine 6G (R6G) down to the trace level of 10(-10) mol L(-1). Besides, New Fuchsin (NF) was also used as a Raman probe to calculate the enhancement factor (EF) of IP6@AgNPs without and with Fe(3+). The SERS activity of IP6@AgNPs happened extreme decrease after one-year storage and could be recovered to great extent aided by the addition of Fe(3+). The Fe(3+) optimized IP6@AgNPs system could be applied to detect thymine at trace level by SERS.

Analysis of Sildenafil in Liquor and Health Wine Using Surface Enhanced Raman Spectroscopy

“…However, the LOD of R6G could reach 5 × 10 −8 M when the R6G was mixed with OTR 202 colloids. The Raman EF was used to measure the enhancement effect, which was calculated as follows [35]:EF=ISERSCRamanIRamanCSERS where ISERS is the integrated intensity of R6G molecules adsorbed on the colloids surface; IRaman is the integrated intensity of the same Raman band obtained without the OTR 202 colloids; CSERS represents the concentration of R6G adsorbed on OTR 202 colloids; and CRaman represents the concentration of R6G that can be detected by ordinary RS.…”

Rapid Quantitative Detection of Deltamethrin in Corydalis yanhusuo by SERS Coupled with Multi-Walled Carbon Nanotubes

“…However, the deltamethrin at 999 cm −1 with a concentration of 2 × 10 −7 M is still obvious using 75 nm AuNPs as SERS substrates. In this work, the enhancement factor (EF) of deltamethrin at 999 cm −1 was calculated from Equation (1) [ 41 , 42 , 43 ]: where is the integrated intensity of deltamethrin molecules adsorbed on the substrate surface. is the integrated intensity of the same Raman band obtained without the AuNPs.…”

Ion inducing surface interaction for improved SERS detection of melamine in fertilizer and soil

“…Based on this opinion, one kind of reagent that not only could aggregate metal nanoparticles to produce plenty of hot spots for elevating SERS effect but also could interact with analyte molecules for adsorbing more molecules on the surface of SERS substrate is desirable for SERS detection. In our previous work, the result that adding Fe 3+ into inositol hexaphosphate (IP 6 ) micelle capped silver nanoparticles (IP 6 @AgNPs) produce plenty of hot spots for greatly improving sensitivity of SERS has been investigated . Coincidentally, Chen and Liu reported that metal ions (Fe 3+ , Zn 2+ , Ca 2+ , etc.)…”