Matrix-Insensitive Sensor Arrays via Peptide-Coated Nanoparticles: Rapid Saliva Screening for Pathogens in Oral and Respiratory Diseases

Plasmonic nanoparticle-based biosensors often report a colorimetric signal through the aggregation or clustering of the nanoparticles (NPs), but these mechanisms typically struggle to function in complex biofluids. Here, we report a matrix-insensitive sensor array approach to detect bacteria, fungi, and viruses whose signal is based on the dissociation of the peptide-aggregated NPs by thiolated polyethylene glycol (HS-PEG) polymers. We show that the HS-PEGs of differing sizes have varying capabilities to dissociate citrate-capped gold nanoparticle (AuNP) and silver nanoparticle (AgNP) assemblies. The dissociative abilities of the HS-PEGs were used in this sensor array to discriminate at the 90% confidence level the microorganisms