CALCA and bacterial infectious disease: This sensor is modified with nanocomposites containing poly(3,4-ethylene dioxythiophene) polystyrene sulfonate (PEDOT:PSS) as the main matrix and functionalized gold nanoparticles (PEDOT:PSS-AuNP@CFP) for the selective and sensitive detection of bacterial infection (BI)-specific biomarker procalcitonin (PCT).