Silica nanoparticle-modified microcomb electrode for voltammetry detection of osteopontin with high sensitivity

Osteosarcoma is a commonly occurring bone malignancy, and it is the second most common cause of cancer deaths in adolescents and children. A sensitive silica nanoparticle (Si-NP) modified current-volt sensor was introduced to identify the osteopontin antigen, a well-known biomarker for osteosarcoma. Si-NP was extracted from the rice husk ash and utilized for the surface functionalization on the interdigitated microelectrode sensing surface. Extracted Si-NP has a spherical shape with uniform distribution, and it is confirmed by field emission scanning electron microscopy and field-emission transmission electron microscopy. Si-NP was layered on the electrode surface through a (3-aminopropyl)triethoxysilane amine linker, and the antibody was immobilized on Si-NP through a glutaraldehyde linker. Osteopontin was effectively detected on the antibody-attached surface, and the determination limit was 0.6 ng/mL. The regression was determined as y = 0.9366x - 1.1113 and the R2 value was 0.9331 and the detection limit of osteopontin was 0.6 ng/mL in the range between 0.3 and 5 ng/mL. In addition, control performance with nonimmune antibodies and albumin did not change the current volt, showing the specific osteopontin identification. This research work brings out the easy and cost-effective method to diagnose osteosarcoma and its etiology.