Utilizing inner filter effect in resonance Rayleigh scattering technique: a case study with silver nanocubes as RRS probe and several analytes as absorbers

Abstract

It was demonstrated that the mechanism of the inner filter effect (IFE) can emerge well in the resonance Rayleigh scattering (RRS) technique and be utilized as a new analytical method in the design of innovative IFE-based sensors. To prove this process, silver nanocubes (Ag NCs) with tunable extinction spectra were selected as RRS probes, and three analytes, doxorubicin (DOX), sunitinib (SUN), and Alizarin Red S (ARS), were considered as the typical absorbers. In addition, in the presence of SUN as a typical analyte, the quenching of the RRS signal of Ag NCs, with λmax of 419nm, was linear in the range 0.01 to 2.5µM of SUN. The limit of detection (LOD) was 0.0025µM. The introduced method was then used to develop a dual-signal assay for the ratiometric determination of Al3+ ions. The suggested dual-signal assay was based on the color changes of ARS caused by Al3+ and the IFE between ARS and Ag NCs. The obtained results showed that the two characteristics of response sensitivity and linear dynamic range are very satisfactory for sensing Al3+ ions. The findings of this study demonstrate that the newly developed IFE mechanism can be employed as an attractive and highly efficient analytical technique for measuring different analytes.