Document Type : Research Paper
Departement of Chemistry, Faculty of Science and Technology, Airlangga University, Kampus C Mulyorejo, Surabaya 60115, Indonesia. Departement of Medical Laboratory Technology, Institute of Health Science Banyuwangi, Jl. Letkol Istiqlah No. 109 Banyuwangi 68422, Indonesia
Departement of Chemistry, Faculty of Science and Technology, Airlangga University, Kampus C Mulyorejo, Surabaya 60115, Indonesia
Faculty of Medicine, Airlangga University, Kampus C Mulyorejo, Surabaya 60115, Indonesia
Silver nanoparticles modified with 4-amino-3-hydrazino-5-mercapto-1,2,4-triazole (AgNPs-AHMT) have been developed as colorimetric sensors for cortisol detection as a stroke biomarker. This method’s principle was based on AgNPs-AHMT aggregation with cortisol due to the hydrogen bonding interaction between the surfaces of AHMT and cortisol. This process caused the color change that can be seen with the naked eye. Then, it is confirmed by ultraviolet-visible (UV-Vis) spectroscopy, particle size analyzer (PSA), Fourier transform infrared (FTIR) spectroscopy, and transmission electron microscopy (TEM). The color of colloidal AgNPs-AHMT changed from yellow to brownish orange, giving a red shift in the localized surface plasmon resonance (LSPR) peak. The quantitative monitor for cortisol determination had good linearity in the range of cortisol concentrations of 1.0–50.0 nM, with a limit of detection (LOD) and a limit of quantification (LOQ) of 0.719 nM and 2.37 nM, respectively. The relative standard deviations (RSD %) for intra-day and inter-day were <3.2 % and <2.26 %, respectively. Moreover, this method was applied for cortisol detection in a saliva sample. So, the simple, rapid, and real-time strategy exhibited a promising potential for cortisol detection in a saliva sample.