Eco-friendly one-pot aqueous synthesis of ultra-thin AuPdCu alloyed nanowire-like networks for highly sensitive immunoassay of creatine kinase-MB

Abstract Advanced nanomaterials have attracted ever-growing interest in design and construction of electrochemical immunosensors, which hold great promise to improve sensitivity in bioanalytical system. In this work, ultra-thin AuPdCu alloyed nanowire networks (NWNs) were controllably synthesized by an eco-friendly one-pot aqueous approach with 4-aminopyridine as a structural directing agent, which served as signal amplifiers in construction of an ultra-sensitive label-free electrochemical immmunosensor for creatine kinase-MB (CK-MB) assay, taking the virtues of the large specific surface area, high electronic conductivity, and good biocompatibility. Importantly, the AuPdCu NWNs efficiently catalyzed the reduction of hydrogen peroxide (H2O2) and thereby enhanced the detection responses. Under the optimal conditions, the as-fabricated immmunosensor showed a wide linear range of 0.001 ∼ 2000 ng mL–1 for CK-MB detection, along with a low limit of detection (LOD = 0.88 pg mL–1, S/N = 3). Thereby, this research was successfully applied for CK-MB quantitation in serum samples with acceptable results, which would provide some valuable guidelines for monitoring other cardiac markers in clinical applications.