This research describes a nanowire network-based method for detecting the activity of myeloperoxidase (MPO), a biomarker of
acute coronary syndromes (ACS). Trimetallic CuPdPt nanowire networks (CuPdPt NWNWs) were prepared by a one-step
chemical reduction method. The metallic precursors quickly form nanowire network structures without the need for additional
capping agents or surfactants. This process creates a product with a clean surface. The NWNWs were dropped onto a glassy
carbon electrode (GCE) to obtain a sensor with good catalytic activity towards the reduction of hydrogen peroxide (H2O2), which
was used as an electrochemical probe working at −0.4 V (vs. SCE). It also provided a large surface for further modification. Next,
an antibody against MPO was immobilized on the modified GCE via the stable conjunction between Cu, Pt, Pd and amino
groups. Upon binding of MPO to the antibody on the GCE, the current response to H2O2 was reduced by 35 μA·cm−2. The
immunosensor had a linear response within the 100 fg·mL−1 to 50 ng·mL−1 MPO concentration range and a 33 fg·mL−1 detection
limit (at an S/N ratio of 3). The recovery of spiked serum samples ranged from 99.8 to 103.6%. This result suggests that the
method can be applied to the quantitation of MPO in human serum samples.

• Amperometric myeloperoxidase immunoassay based on the use of CuPdPt nanowire networks