Determinants of bone fragility: chitosan–TiO 2 -modified ELISA surface for enhanced detection of CTX-I

Abstract Objectives Osteoporosis is a silently developing condition marked by decreasing the bone mineral density, leads to bone fragility. Diagnosis of osteoporosis is critical, and the conventional radiological techniques are costly, makes difficult to access for routine monitoring. Therefore, researchers are using blood-based biomarkers for identifying osteoporosis, to be convenient and cheaper. Methods This study reports a highly sensitive and selective titanium oxide (TiO 2 ) nanoparticle-modified ELISA for the detection of bone resorption biomarker, C-terminal telopeptide of type I collagen (CTX-I). Chitosan-TiO 2 modification increases the area of polystyrene ELISA (PS) surface and facilitates more anti-CTX-I immobilization for robust interaction with CTX-I. Results With proper orientation of biomolecules on the above surface increases the signal generation and lowers the detection limit of CTX-I to 0.05 ng/mL. Besides, the nanomaterial-modified ELISA exhibits higher selectivity, confirmed through CTX-I-spiked detection in serum and tested with relevant control proteins, BSA, CTX-II, and N-terminal telopeptide of type I collagen (NTX). Conclusions This surface-enhanced ELISA offers a promising alternative for CTX-I detection at its lower level and helps monitoring the disease progression and therapeutic response, besides, it require further clinical validation.