The Comparative of α- and β-Cyclodextrin as Stabilizing Agents on AuNPs and Application as Colorimetric Sensors for Fe3+ in Tap Water

Adhi Maulana Yusuf (Research Centre for Chemistry, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Building 452, Serpong, Banten 15314, Indonesia Department of Chemical Engineering, Institut Teknologi Indonesia, Jl. Raya Puspiptek, Serpong, Banten 15)
Satrio Kuntolaksono (Department of Chemical Engineering, Institut Teknologi Indonesia, Jl. Raya Puspiptek, Serpong, Banten 15314, Indonesia)
Agustina Sus Andreani (Research Centre for Chemistry, National Research and Innovation Agency (BRIN), Kawasan Puspiptek, Building 452, Serpong, Banten 15314, Indonesia)

Indonesian Journal of Chemistry
Vol 23, No 6 (2023)

In this study, AuNPs were reduced using ortho-hydroxybenzoic acid (o-HBA) and various stabilizing agents (α-CDs and β-CDs). The stability, shape, size, and sensitivity of the Fe3+ detection of AuNPs α-CDs and AuNP β-CDs are compared. Both nanomaterials were characterized using ultraviolet-visible (UV-vis) spectroscopy, Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopes (TEM). After the addition of Fe3+, the absorption rate of surface plasma resonance (SPR) increased to 524 nm, and the color of AuNPs α-CDs and AuNPs β-CDs was changed from pink to red and purple, respectively. AuNPs α-CDs are more uniform in shape and size than AuNPs β-CDs with a size of 23.34 nm. Further, AuNPs α-CDs are more stable, and the absorption rate at 524 nm wavelength decreases by 17.76%. AuNPs α-CDs have a good linear relationship with a linear regression coefficient of 0.996. The sensitivity of AuNPs α-CDs was good with LoD and LoQ both with 1.21 and 4.02 ppm, respectively. These results show that the sensor is superior in determining Fe3+. In addition, AuNPs α-CDs were used to detect Fe3+ in the tap water in South Tangerang, Banten, Indonesia.