Electrochemiluminescence detection of cardiac troponin I based on Au–Ag alloy nanourchins†
In this work, an Au–Ag alloy nanourchin (Au–Ag alloy NU) based electrochemiluminescent (ECL) sensor for the measurement of cardiac troponin I (cTnI) was developed. The as-prepared Au–Ag alloy NUs exhibited higher specific surface area and better conductivity owing to their unique urchin-like morphology, which resulted in excellent electrocatalytic activity towards H2O2 in the luminol–H2O2 ECL system. We have found that the Au–Ag alloy NUs could enhance the ECL signal in the luminol–H2O2 solution. Based on these facts, a facile and label-free ECL immunosensor has been constructed for the analysis of cTnI, a cardiac biomarker, with a wide linear range of 3.5 pg mL−1–350 μg mL−1. This novel ECL immunosensor has good stability and reproducibility, showing potential application in clinical diagnostics. In addition, a non-enzymatic electrochemical sensor for H2O2 was also fabricated, with a wide linear detection range of 100 nM–200 μM, a low limit of detection of 45 nM and a fast response time (less than 2 s).
- This article is part of the themed collection: Versatile Electrochemical Approaches