Synthesis of Palladium Nanowires on Flagella Template for Electrochemical Biosensor Detection of microRNA-21

Simple SummaryThis study proposed a new method for extractingE. coliflagella, which served as a template for synthesizing palladium (Pd) nanowires. By improving the flagella extraction process, we successfully produced Pd nanowires with better structure and function, which could have important applications in technology and medicine. Traditional methods often led to impurities that interfered with nanomaterial synthesis, but our method provided a cleaner and more efficient way of producing high-quality nanowires. UsingE. coliflagella as a template offered environmental benefits, as it eliminated the need for toxic chemicals and reduced energy consumption. This eco-friendly approach was also safer and more reliable for practical applications. Our research also showed how the functional groups on the flagella surface helped form strong bonds with metals, improving the nanowire formation process. This study highlighted the potential of using biological templates for nanomaterial synthesis, contributing to the development of greener and more efficient technologies.In recent years, the use of bacterial flagella as biomimetic templates has gained increasing attention in nanomaterial synthesis due to their unique structural and functional properties. In this study, we optimized the flagella extraction method and achieved a high concentration of flagella solution. Flagella were isolated fromEscherichia coli. Surface characterization revealed that the flagella had abundant functional groups, such as amino and carboxyl groups, which can serve as nucleation sites for the controlled nucleation and growth of metal nanomaterials. Using bacterial flagella as a template, we synthesized one-dimensional palladium nanowires (Fla-Pd NWs). The results of morphological and phase analyses showed that the synthesized palladium nanoparticles were uniformly and densely distributed on the surface of the flagella. Moreover, the Fla-Pd nanowires exhibited superior electrocatalytic activity, which was applied to develop an electrochemical biosensor. This biosensor was used to detect the early breast cancer biomarker microRNA-21 and exhibited a linear range of 0.66–1.98 µmol/L and a detection limit of 0.78 µmol/L. The method demonstrated high selectivity and reusability, making it a promising strategy for early cancer diagnosis.