Low-Temperature Substrate: Detection of Viruses on Cold Chain Food Packaging Based on Surface-Enhanced Raman Spectroscopy

Viruses are mostly resistant to low temperatures and can survive for a long time and maintain their infectivity at temperatures below 0 °C. Therefore, realizing virus detection at low temperatures is a great challenge. Subzero temperatures change the state of the water-soluble substrate, increasing the difficulty of detection. In this work, we designed a novel enhancement substrate to obtain SERS signals of biomolecules stably at low temperatures. For the first time, methanol solvent was introduced into the aqueous system of silver nanoparticles modified with iodide ions. The introduction of methanol solvent not only serves as an anticoagulant to keep the system stable at low temperatures, but it can also improve nanoparticles and form a “hot spot”, which is more suitable for virus detection. This low-toxicity, rapid, and highly sensitive in situ detection technique lays the foundation for the development of SERS technology in the field of food and life sciences.