A Dual-Mode "Turn-On" Ratiometric Luminescent Sensor Based on Upconverting Nanoparticles for Detection and Differentiation of Gram-Positive and Gram-Negative Bacteria.

ABSTRACT: Infectious bacterial diseases, intensified by antibiotic resistance, cause millions of deaths annually and pose risks beyond human health, including water and food contamination. Current diagnostics are often slow, require complex equipment, and lack specificity, highlighting the need for rapid and reliable detection methods. To address this, we developed a luminescent sensor based on NaYF₄ upconverting nanoparticles (UCNPs) doped with Er³⁺ or Tm³⁺, coated with COOH-PEG₄-COOH, and functionalized with vancomycin (Van) or polymyxin-B (Poly) to selectively target Gram-positive and Gram-negative bacteria, respectively. Gold nanoparticles (AuNPs) served as quenchers, enabling a ratiometric "turn-on" mechanism: upon bacterial binding, the UCNP emission

SUBMITTER: Arai MS 

PROVIDER: S-EPMC12509115 | biostudies-literature | 2025 Oct

REPOSITORIES: biostudies-literature