Label-free and highly sensitive electrochemical immunosensor for alkaline phosphatase

As a critical hydrolase regulating bone mineralization and skeletal development, alkaline phosphatase (ALP) necessitates simplified detection methodologies. In this work, we developed a label-free electrochemical immunosensor of ALP by leveraging Ti₃C₂Tₓ nanoribbon/gold nanoparticle hybrids as functional electrode modifier which was prepared just via an easy self-reduction method. Comprehensive characterization via scanning electron microscopy, X-ray diffraction and X–ray photoelectron spectroscopy as well as electrochemical impedance spectroscopy confirmed the hybrid's hierarchical architecture. Antibody immobilization was achieved through cysteamine-mediated covalent conjugation. The detection mechanism exploits [Fe(CN)₆]³ ⁻/⁴⁻ redox signal attenuation upon target-induced immunocomplex formation, enabling label-free quantification. Optimized operational parameters yielded a dynamic detection range of 10 – 900 U/L with a 2 U/L limit of detection, demonstrating potential clinical viability for the skeletal related diseases screening.