A review on gold nanowire based SERS sensors for chemicals and biological molecules

Surface-enhanced Raman scattering (SERS) has emerged as a powerful technique for detecting and analyzing chemical and biological molecules at ultra-low concentrations. The effectiveness of SERS largely depends on structures with sub-10 nm gaps, prompting the proposal of various nanostructures as efficient SERSactive platforms. Among these, single-crystalline gold nanowires (AuNWs) are particularly promising due to their large dielectric constants, well-defined geometries, atomically smooth surfaces, and surface plasmon resonance across the visible spectrum, which produce strong SERS enhancements. This review comprehensively explores the synthesis, functionalization, and application of Au NWs in SERS. We discuss various methods for synthesizing AuNWs, including the vapor transport method, which influences their morphological and optical properties. We also review practical applications in chemical and biosensing, showcasing the adaptability of Au NWs-based SERS platforms in detecting a range of analytes, from environmental pollutants to biological markers. The review concludes with a discussion on future perspectives that aim to enhance sensor performance and broaden application domains, highlighting the potential of these sensors to revolutionize diagnostics and environmental monitoring. This review underscores the transformative impact of AuNW-based SERS sensors in analytical chemistry, environmental science, and biomedical diagnostics, paving the way for next-generation sensing technologies.