Agustina Sus Andreani, Syarah Umu Zahro, Agustina Vidiawati, Ahmad Fathoni
Dengue hemorrhagic fever (DHF) is still a serious health problem in Indonesia. Early detection of the NS1 antigen is an important approach because this antigen appears from the first day of infection. This study aims to develop a colorimetric biosensor based on gold nanoparticles (AuNPs) for the rapid and selective detection of NS1 antigen. AuNPs were synthesized using α-cyclodextrin (α-CDs) as a reducing and stabilizing agent through a heating method at 98 °C for 15 min. Furthermore, the surface of AuNPs was modified with mercaptoundecanoic acid (MUA) to add carboxylic groups, activated with EDC/NHS to allow bioconjugation with NS1 antibodies (AuNPs-mAb). The UV-Vis characterization results showed a shift in the Surface Plasmon Resonance (SPR) peak from 517 nm to 530 nm after interaction with the NS1 antigen, accompanied by a decrease in absorbance from 0.304 to 0.108 and a color change in the solution from reddish-purple to faint purple in less than 5 min. The biosensor showed good sensitivity with a Limit of Detection (LOD) of 22.02 ng ml-1, linearity R2 = 0.996, and stability up to 14 days. Selectivity testing against interferents such as glucose, cholesterol, and uric acid showed no cross-reactivity. Applicative tests with human serum proved the effectiveness of detection in real conditions. With the advantages of a fast, practical method that does not require complex equipment, this AuNPs-mAb biosensor has the potential to be an efficient early diagnostic tool for dengue virus infection. It can be further developed for nanoparticle-based clinical applications. © (2025), (Iranian Chemical Society). All rights reserved.
Research Centre for Chemistry, National Research and Innovation Agency (BRIN), Tangerang Selatan, Banten, 15314, Indonesia; Department of Chemistry, Faculty of Mathematics and Natural Sciences, Universitas Negeri Semarang, Semarang, 50229, Indonesia; Department of Chemistry, Syarif Hidayatullah State Islamic University, Jl. Ir. H. Djuanda No. 95, Banten, Ciputat, 15412, Indonesia
