Synergistic molecular assembly of an aptamer and surfactant on gold nanoparticles for the colorimetric detection of trace levels of As³⁺ ions in real samples

다국어 초록 (Multilingual Abstract)

<P>The use of the synergistic molecular assembly of an aptamer and cetyltrimethylammonium bromide (CTAB) on gold nanoparticles (AuNPs) is described for the selective and sensitive colorimetric recognition of As<SUP>3+</SUP> ions in water samples. The As<SUP>3+</SUP> ions coordinate with Ars-3 aptamer-AuNPs, causing aggregation in the presence of CTAB, which induces a red-shift in the surface plasmon resonance (SPR) band and a visual change in the color. The aptamer has shown a strong tendency to bind with As<SUP>3+</SUP> ions using CTAB as a binder, exhibiting good linearity between the absorption ratio (<I>A</I>650/<I>A</I>520) and the concentration of As<SUP>3+</SUP> ions (1.0-100 ppb) with a detection limit of 16.9 ppb. In contrast, other chemical species (metal ions and anions) did not induce these changes at all, and thus the aptasensor is highly specific for As<SUP>3+</SUP> ion sensing. The spectroscopic and TEM results show high selectivity for As<SUP>3+</SUP> ion sensing and the assay is completed within 30 min. The aptamer-AuNP-based colorimetric method illustrates the potential utility for screening As<SUP>3+</SUP> ion levels in real samples. The developed aptasensor was successfully applied for the detection of As<SUP>3+</SUP> ions in water and cosmetic samples, signifying its remarkable application for As<SUP>3+</SUP> ion sensing in real samples.</P>