Two-Dimensional Cs₂AgBiBr₆-Based Biosensor for Selective and Sensitive Detection of Cardiac Biomarker Troponin I

Inspired by graphene and transition-metal dichalcogenides (TMDs), a considerable focus has been centered on investigating and exploring two-dimensional (2D) layered materials that possess excellent electronic, optical, physical, and chemical properties. Owing to their nontoxic nature, inherent stability, and exceptional optical and electrical sensitivity, 2D lead-free double perovskites have attracted considerable research attention. In this work, we present the fabrication of Au–Au/Ag yolk–shell plasmonic nanomaterial-decorated 2D Cs 2 AgBiBr 6 based biosensors for sensitive and selective detection of the cardiac biomarker cardiac troponin I (cTnI). The Cs 2 AgBiBr 6 -based biosensor showed outstanding sensing capabilities, achieving a detection limit of 10 pg/mL, which is considerably below the typical concentration of cTnI in the human blood, highlighting the potential utility of plasmonic nanomaterials and Cs 2 AgBiBr 6 in highly sensitive sensing applications.