AuPt nanocrystals/polydopamine supported on open-pored hollow carbon nanospheres for a dual-signaling electrochemical ratiometric immunosensor towards h-FABP detection

For early diagnosis and prevention of acute myocardial infarction (AMI), accurate and sensitive analysis of cardiac biomarkers by a single test has faced substantial challenge. A novel electrochemical immuno-sensing platform was built for untrasensitive assay of heart-type fatty acid-binding protein (h-FABP) via multi-signal output. This immunosensor utilized Au nanodendrites/chitosan-grafted-ferrocene (Au NDs/Chit-g-Fc) as the substrate and thionine-absorbed AuPt nanocrystals/polydopamine/open-pored hollow carbon spheres (Thi/ AuPt/PDA/OHCSs) as the label material, producing two independent electrochemical signals from the Fc and Thi probes, respectively. For such assay of the target h-FABP in the immuno-sensing system, the ratios (I-Thi / I-Fe) between the double signals showed a broad dynamic range of 0.001-200.0 ng mL(-1) and a low detection limit of 0.53 pg mL(-1) (S/N = 3). This ratiometric sensor exerts a far-reaching influence on other biomarkers researches in practical applications.

Automated summary

A novel electrochemical immuno-sensing platform was developed for ultra-sensitive detection of heart-type fatty acid-binding protein, showing a broad dynamic range and low detection limit. This ratiometric sensor has implications for other biomarker research in practical applications.