Microfluidic Synthesis of Ag@Fe3o4-Coated Helical Microfibers for High-Sensitivity Surface Enhanced Raman Spectroscopy

作     者：Sharma, Kajal Nguyen, Lan Liu, Jingying Cao, Chang Ou, Qingdong Jasieniak, Jacek Gundabala, Venkat Alan, Tuncay 

作者机构：Dynamic Micro Devices Laboratory Department of Mechanical and Aerospace Engineering Monash University ClaytonVIC3800 Australia Bombay Powai Mumbai400076 India Department of Materials Science and Engineering Monash University ClaytonVIC3800 Australia ARC Centre of Excellence in Exciton Science Monash University ClaytonVIC3800 Australia  Faculty of Innovation Engineering Taipa999078 China 

出 版 物：《SSRN》 

年 卷 期：2025年

核心收录：

主　　题：High resolution transmission electron microscopy 

摘      要：HypothesisSurface-enhanced Raman spectroscopy (SERS) is a powerful technique that significantly enhances the Raman scattering signals of molecules adsorbed on specific substrates to detect a wide range of chemical and biological analytes with a high sensitivity and specificity. Traditional substrates often have limitations in terms of reproducibility, sensitivity, and ease of fabrication. Despite their huge potential for rapid detection, there is a high demand for multifunctional substrates that can be produced at a low cost and are capable of flexible bending and mobility for sample collection. Here, we hypothesize a helical microfibrous substrate uniformly coated with nanoparticles (NPs) will enhance SERS detection by increasing the surface area for analyte adsorption and improving light scattering, leading to stronger signal amplification compared to traditional flat ***@Fe3O4 core-shell NPs were synthesized via a microwave-assisted solvothermal method, followed by PEI coating. These NPs were then used to coat PVDF-HFP helical microfibers in a microfluidic device in the presence of an external magnet. The flow rates of the inner and outer solutions were varied to study their effects on microfiber morphology and deposition and to evaluate their SERS sensitivity for Rhodamine B sensing across a wide concentration range (10-10 - 10-5 M).FindingsThe finding confirmed that the magnetically assisted microfluidic synthesis of Ag@Fe3O4 core-shell NP-decorated helical microfibers resulted in a significant enhancement of the SERS effect. Characterization by Scanning Electron Microscopy (SEM), High-Resolution Transmission Electron Microscopy (HR-TEM), and X-Ray Diffraction (XRD) confirmed the successful synthesis of Ag@Fe3O4 core-shell NPs and their deposition on the helical microfiber. The 3D substrate demonstrated a high SERS sensitivity for Rhodamine B sensing across a wide concentration range (10-10 - 10-5 M). © 2025, The Authors. All rights reserve