Sandwich biosensing on a nanodiamond-modified interdigitated electrode for monitoring the occurrence of osteosarcoma

Abstract

BackgroundOsteosarcoma is a highly heterogeneous manifestation with varied subtypes and is diagnosed by imaging techniques; however, quantification of blood-based biomarkers boosts genuine osteosarcoma identification. MethodsHerein, a sensitive sandwich pattern with aptamer and antibody was conducted on a nanodiamond-modified interdigitated electrode surface to identify osteopintin, a well-suited biomarker for osteosarcoma. Diamond nanoparticles measured as 5±3 nm by a high-resolution microcopy were attached to the sensing surface through chemical [(3-aminopropyl)triethoxysilane, 1,1′-carbonyldiimidazole] and biological (biotin-streptavidin) linkers to immobilize the aptamer on the nanodiamond. The detection limit of osteopontin was attained to be 100 pM in phosphate-buffered saline (PBS)-spiked samples using a sandwich, and it was 1 nM with only aptamer at the coefficient determinations R2 values of 0.99 (y=1.2106x-1.0127) and 0.98 (y=1.0086x-0.7867), respectively, on linear concentrations of 0.1-100 nM osteopontin. Furthermore, biofouling experiments with complementary aptamer sequences, albumin and control samples did not increase the current responses, confirming the specific identification of osteopontin, which was further evidenced in serum-containing samples. Significant FindingsThis biosensing assay quantifies osteopontin at lower levels and diagnoses osteosarcoma.