DEVELOPMENT OF FLUORESCENT NANOPARTICLES BASED ON NATURAL SILICA AS DETECTORS OF IGG-COVID-19 ANTIBODIES

• Main Author: Apriyani, Firda
• Format: Theses
• Language: Indonesia
• Online Access: https://digilib.itb.ac.id/gdl/view/72900
• Institution: Institut Teknologi Bandung

The Covid-19 outbreak caused by the Severe Acute Respiratory Syndrome Coronavirus-2 (SARS-CoV-2) virus was declared a global pandemic by the World Health Organization (WHO) in March 2020. The health crisis caused by the Covid- 19 pandemic has required early detection methods to limit the spread of the virus. Biosensors are one of the detection methods that can provide rapid, sensitive, and selective results for the presence of biomolecules such as antibodies. This research uses an optical biosensor based on fluorescent silica nanoparticles using Rhodamine B as a fluorophore to detect IgG-Covid-19 antibodies through immunoassay. The sol-gel process carried out fluorescent Silica Nanoparticles (FSNP) synthesis. Xray Diffraction (XRD) analysis showed that the FSNP had an amorphous phase. Based on surface area analysis using the Brauner Emmett-Teller (BET) method, a surface area of 208.956 m2/g was obtained. FSNP surface modification was carried out by the hydrosilylation method to bind the receptors Anti IgG receptors and followed by changes using EDC and NHS as crosslinkers to obtain the final result FSNP-Anti IgG. The Fourier Transform Infra-Red (FTIR) analysis showed that the anti-IgG successfully binds to FSNP based on the resulting amide I and II peaks at 1641 cm-1 and 1530 cm-1. Increasing the fluorescence intensity of FSNP-Anti-IgG at 545 nm excitation and 582 emissions showed the successful detection of IgGCovid- 19 antibody based on the immunoassay. Optimal response time was observed after 15 minutes of incubation of IgG-Covid-19 antibody with FSNP-Anti IgG. The sensitivity of FSNP-Anti-IgG in detecting IgG-Covid-19 antibodies was obtained based on the linearity of fluorescence intensity with a concentration range of 10-2-10-8 ?g/mL with a Limit of Detection (LoD) value of 5.3 fg/mL. Consequently, with their advantages of sensitivity and speed, biosensors based on fluorescent silica nanoparticles can be further developed as a promising platform for detecting antibodies.