A Novel Redox‐free Immunosensor Concept Based on Cobalt Phthalocyanine@carbon Nanotubes Pseudocapacitor for Cardiac B‐type Natriuretic Peptide Detection

B‐type natriuretic peptide (BNP) is a selective biomarker for cardiac diagnosis and prognosis of patients with cardiac insufficiency or heart failure, which means the pump function of cardiac muscle is reduced. A pseudocapacitive immunosensor was developed based on faradaic currents generated by a reduction‐reaction with a metallocyanine modified‐carbon nanotube surface. This technique is based on changes in interface by antigen‐antibody interactions, which perturbs the dependent‐diffusion potential reducing the charge transfers proportionally to the BNP captured. This new concept allows new perspectives for point‐of‐care tests since it is simpler and faster to manage with direct measurements of samples than conventional immunosensors.