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

Abstract

• Ultra-thin AuPdCu NWNs were synthesized by an eco-friendly one-pot aqueous method. • 4-Aminopyridine was employed as structure-directing agent in this synthesis. • The ultra-thin nanowire networks provided enlarged specific surface area and abundant active sites. • The resultant immunosensor displayed a satisfactory assay for CK-MB in this research. 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 (H 2 O 2 ) 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.