Label-Free Pathogen Detection Based on Yttrium Doped Carbon Nanoparticles Up to Single-Cell Resolution

The capability to detect bacteria at a low cell density is critical to prevent the delay in therapeutic intervention and to avoid the emergence of antibiotic-resistant species. Till date, significant advancement has been made to develop a sensing platform for rapid and reliable bacterial detection. However, critical requirements i.e. limit of detection (LOD), fast time of response (TOR), ultra-sensitivity with high reproducibility and ability to distinguish between bacterial strains have yet to be met within a single sensing platform. In this contribution, we present a novel label-free sensor based on pH-sensitive fluorescent yttrium doped carbon nanoparticles (YCNPs) embedded in agarose that can rapidly and accurately detect and discriminate pathogens in real-time. The developed sensor matrix presented pH-triggered aggregation-induced emission quenching of YCNPs in a wide pH range. When the pH decreased from 10.0 to 4.0, the fluorescence of the matrix decreased linearly (R2 = 0.9229). The sensor ‘s high ...