Stabile SERS Encoded Silver Silica Nanocomposites for Industrial Labeling – The Case of COVID-19 Diagnosis

Biosensors, especially those with a SERS readout, are required for an early and precise healthcare diagnosis. Unreproducible SERS platforms hamper clinical SERS. Here we report a synthetic procedure to obtain stabile, reproducible and robust highly-SERS performing nanocomposites for labelling. We control the NPs agglomeration and codification which results in an increased number of hot spots, thus exhibiting reproducible and superior Raman enhancement. We studied fundamental aspects affecting the plasmonic thiol bond resulting in pH exhibiting a determining role. We validated their biosensing performance by designing a SERS-based ELISA SARS-CoV-2 detections assay which exhibits limits of detection below 0.01 ng/μL.