Silver nanoparticles as a new colorimetric probe for determination of oxalic acid in urine

Basharzad P. F., Farhadi K., Forough M., Molaei R.

Sensor Letters, vol.14, no.9, pp.906-912, 2016 (SCI-Expanded) identifier

  • Publication Type: Article / Article
  • Volume: 14 Issue: 9
  • Publication Date: 2016
  • Doi Number: 10.1166/sl.2016.3714
  • Journal Name: Sensor Letters
  • Journal Indexes: Science Citation Index Expanded (SCI-EXPANDED), Scopus, Aerospace Database, Biotechnology Research Abstracts, Communication Abstracts, Metadex, Civil Engineering Abstracts
  • Page Numbers: pp.906-912
  • Middle East Technical University Affiliated: No


Copyright © 2016 American Scientific Publishers All rights reserved.A new and high potential colorimetric sensor for the selective recognition and monitoring of oxalic acid (OA) in aqueous samples has been developed based on the interaction between OA and unmodified silver nanoparticles (AgNPs). The fresh synthesized silver nanoparticles are yellowishbrown in color due to the intense SPR absorption band. It was found that AgNPs were aggregated in the presence of oxalic acid, resulting in a considerable decrease in the intensity of the surface plasmon resonance (SPR) absorption band of AgNPs and formation of new peak in at longer wavelengths. So, we propose a simple, cost effective, rapid and selective colorimetric sensor for the detection of oxalic acid using AgNPs in aqueous media. Results demonstrated that other similar organic acids cannot change the color of AgNPs solution in the same conditions, suggesting the selectivity of the proposed method toward OA. The color change was monitored by naked eye and UV-Vis spectrophotometer. Also, the effect of the concentration of oxalic acid to the color change of AgNPs was considered and the LOD for OA was estimated 3.3 μM. The proposed method has been successfully used for the determination of oxalic acid in human urine samples.