Rapid and Sensitive Detection of Flavor Nucleotides in Aquatic Products by SERS Sensors with Unique Virus-Like Spike Structures

Flavor nucleotides serve as key indicators for assessing the freshness of aquatic products. However, their rapid degradation over time poses a significant challenge for accurate detection, underscoring the need for rapid and highly sensitive analytical methods. In this study, a novel Au-Ag@Si surface-enhanced Raman scattering (SERS) sensor featuring a virus-like spike structure was fabricated by integrating physical vapor deposition and wet-chemical synthesis. Driven by a galvanic replacement reaction, well-ordered Au-Ag nanostructures were formed, which significantly enhanced the localized surface plasmon resonance through abundant contact sites and strong electromagnetic fields. This SERS platform was subsequently employed for the ultrasensitive and rapid detection of inosine monophosphate (IMP) and adenosine monophosphate (AMP), achieving limits of detection (LODs) as low as 1×10 -5 ppm and enhancement factors (EFs) of 2.33×10 4 and 3.22×10 4 , respectively. These results represent nearly an order of magnitude improvement in detection performance over conventional methods. The sensor was further validated in Procambarus clarkii using an internal standard method and simulated transport experiments. This study demonstrated that the virus-like Au-Ag@Si SERS sensor significantly enhances the detection of AMP and IMP, enabling rapid and ultrasensitive assessment of aquatic product freshness.