Trimetallic hybrid nanodendrites and magnetic nanocomposites-based electrochemical immunosensor for ultrasensitive detection of serum human epididymis protein 4

Abstract Alloy nanomaterials with various morphologies have showed their potential application in electrochemical signal amplification. However, it is still challenging to fabricate stable multimetallic nanomaterials with large surface area and strong electrochemical activity for the further enhancement of electrochemical sensors’ performance. Here, the trimetallic AgPtCo nanodendrites (NDs) were synthesized as powerful redox probe and highly efficient signal amplifier for electrochemical signal readout. A robust and ultrasensitive electrochemical immunosensor, based on AgPtCo NDs and magnetic nanocomposites (Fe 3 O 4 @SiO 2 @Au MNCs), was successfully developed to detect serum human epididymis protein 4 (HE4). The established method, drawing upon the strong electrochemical activity of AgPtCo NDs and the enrichment and separation effect of MNCs, exhibited a wide linear range (0.001-50 ng mL -1 ) and a low detection limit (0.487 pg mL -1 ). Besides, the developed sensor was applied to analyze the concentration of HE4 in real samples and the results achieved were consistent with those of clinical methods. Thus, this AgPtCo NDs and MNCs based electrochemical immunosensor might become a powerful alternative approach for ultrasensitive detection of various serum biomarkers associated with early diagnosis and treatment of diseases.