Fe(III) Mixed IP6@Au NPs with Enhanced SERS Activity for Detection of 4-ATP

Surface Enhanced Raman Scattering (SERS) has been widely applied in many research fields such as biological detection and chemical analysis. However, for the common Au nanoparticles, it's too hard to guarante the three aspects: the great enhanced effect, the controllable aggregation and the uniformity of nanoparticles, the environmental friendliness and biocompatibility of nanoparticles. In this paper, phytate acid (IP6)-coated Au nanoparticles (IP6@Au NPs) are more stable and have a higher enhancement factor than Au nanoparticles. In order to achieve the uniformity of the spherical IP6-coated@Au nanoparticles (IP6@Au NPs), IP6 was used as a soft template. In the presence of IP6, IP6@Ag nanoparticles were first synthesized by reducing AgNO₃ with trisodium citrate, then IP6@Au NPs were obtained by reducing HAuCl₄ with Ag nanoparticles. The IP6@Au NPs exhibit excellent Raman signal enhancement by using p-aminothiophenol (4-ATP) as the probe molecules. The effects of Fe³⁺ on the performance of IP6@Au NPs SERS substrates were also studied. The results show that SERS has the best enhancement effect when adding proper amount of Fe³⁺ (0.56 PPM), and the limit of detection was 10^-7 M 4-ATP.