Dual‐signal immuno‐competitive determination of brain natriuretic peptide based on magnetic nanozyme

Abstract

Brain natriuretic peptide (BNP) has been a disease marker in the diagnosis of heart failure. In this study, gold nanoparticles modified with Hemin (H‐AuNPs) as nanozymes were used to oxidize ABST and MB to amplified colorimetric and electrochemical redox signals respectively. BNP was combined with H‐AuNPs (BNP‐H‐AuNPs) through electrostatic adsorption to construct competitive nanozyme probes. Target BNP in the sample compete with BNP‐H‐AuNPs to bind the antibody‐modified magnetic nanoparticles (AntiBNP‐MNPs). Due to the excellent catalytic performance of the nanozyme, BNP can be observed well by colorimetric and electrochemical assays. Electrochemical method ensured more accurate detection of BNP with a wide detection range (1–200 pg/mL) and a low detection of limit (0.03 pg/mL). Meanwhile, the results of the experiment can be easily observed with the naked eye by simple colorimetric method with a range from 5 ng/mL to 25 ng/mL and a limit of detection down to 80.3 pg/mL. Thus, based on the important role of H‐AuNPs, this assay has exhibited potential value of detection the other small proteins through this competitive nanozyme method.