A trimetallic CuAuPd nanowire as a multifunctional nanocomposites applied to ultrasensitive electrochemical detection of Sema3E.

In this work, an innovative metal nanowire-based biosensor designed for the quantitative detection of semaphorin 3E (Sema 3E), a potential biomarker for several diseases such as atherosclerosis and systemic sclerosis, was proposed. For the biosensor fabrication, novel trimetallic CuAuPd nanowire networks (NNWs) were synthesized to utilize as a multifunctional substrate for electron transfer, antibody immobilization and signal amplification via catalyzing the decomposition of hydrogen peroxide. A facile one-step approach was employed at room temperature and atmospheric pressure to synthesize the CuAuPd NNWs, exhibiting advantages of high specific surface area, excellent electron transport property, superior catalytic property, and excellent biocompatibility. Cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and atomic force microscopy (AFM) was examined to determine the successful fabrication process of the sensor, while the electrochemical method of amperometric i-t curve was used for the detection of target. The results demonstrated accepted stability, excellent selectivity, sensitivity and accuracy, which displayed a linear range of the analyte concentration that covered 100 fg mL-1 to 10 ng mL-1, with a low detection limit of approximately 1.5 fg mL-1 (S/N = 3), achieved under optimum conditions. This result suggests that the sensor could be applied to the serum samples for Sema 3E quantitation.