A metal–organic framework-based fluorescence resonance energy transfer nanoprobe for highly selective detection of Staphylococcus Aureus

• Published in: Journal of materials chemistry. B, Materials for biology and medicine Materials for biology and medicine, 2023-09, Vol.11 (35), p.8519-8527
• Main Authors: Qiao, Jing, Chen, Xuanbo, Xu, Xingliang, Fan, Ben, Guan, Ying-Shi, Yang, Hong, Li, Quan
• Format: Article
• Language: English
• Subjects: Acetic acid; Bacteria; Cell walls; Clean energy; Energy transfer; Fluorescein isothiocyanate; Fluorescence; Fluorescence resonance energy transfer; Fruit juices; Health risks; Metal-organic frameworks; Resonance; Saliva; Vancomycin; Zirconium
• ISSN: 2050-750X; 2050-7518
• DOI: 10.1039/d3tb01428b

Survival and infection of pathogenic bacteria, such as Staphylococcus aureus ( S. aureus ), pose a serious threat to human health. Efficient methods for recognizing and quantifying low levels of bacteria are imperiously needed. Herein, we introduce a metal–organic framework (MOF)-based fluorescence resonance energy transfer (FRET) nanoprobe for ratiometric detection of S. aureus . The nanoprobe utilizes blue-emitting 7-hydroxycoumarin-4-acetic acid (HCAA) encapsulated inside zirconium (Zr)-based MOFs as the energy donor and green-emitting fluorescein isothiocyanate (FITC) as the energy acceptor. Especially, vancomycin (VAN) is employed as the recognition moiety to bind to the cell wall of S. aureus , leading to the disassembly of VAN-PEG-FITC from MOF HCAA@UiO-66. As the distance between the donor and acceptor increases, the donor signal correspondingly increases as the FRET signal decreases. By calculating the fluorescence intensity ratio, S. aureus can be quantified with a dynamic range of 1.05 × 10 3 –1.05 × 10 7 CFU mL −1 and a detection limit of 12 CFU mL −1 . Due to the unique high affinity of VAN to S. aureus , the nanoprobe shows high selectivity and sensitivity to S. aureus , even in real samples like lake water, orange juice, and saliva. The FRET-based ratiometric fluorescence bacterial detection method demonstrated in this work has a prospect in portable application and may reduce the potential threat of pathogens to human health.