Atomic Fe-Centered Hemin-TiO₂ Graphdiyne Nanozyme Sensor for Colorimetric Fingerprinting of Bacterial Extracellular...

Area of Science:

• Biomaterials Science
• Nanotechnology
• Analytical Chemistry

Background:

• Accurate identification of urinary pathogens is crucial for managing urinary tract infections (UTIs).
• Bacterial extracellular vesicles (bEVs) are promising diagnostic targets due to pathogen-specific surface antigens.
• Current bEV isolation methods are time-consuming (up to 72 hours), hindering clinical application.

Purpose of the Study:

• To develop a rapid and accurate method for identifying bEVs directly from urine samples.
• To overcome the limitations of traditional bEV isolation techniques for UTI diagnostics.
• To create a point-of-care diagnostic platform for UTIs.

Main Methods:

• Invented a three-dimensional biomimetic nanozyme (TiO2 nanoparticles-bridged Hemin on graphdiyne) for selective bEV capture and enhanced peroxidase-like activity.
• Utilized the nanozyme's specific coordination interactions with lipopolysaccharide O-antigens on bEVs for recognition.
• Employed a colorimetric approach with pH-dependent activity suppression and machine learning for bEV subtype classification.

Main Results:

• The nanozyme selectively captured bEVs and exhibited pH-dependent peroxidase-like activity.
• Distinctive colorimetric fingerprints were generated upon bEV recognition.
• The platform achieved 100.0% diagnostic accuracy within 30 minutes in clinical validations.

Conclusions:

• The intelligent colorimetric sensor array enables rapid and accurate identification of bEVs in UTIs.
• This technology significantly reduces diagnostic time compared to conventional methods.
• The developed platform shows great promise for point-of-care UTI management.