Coacervate-Based Plexcitonic Assembly toward Peroxidase-like Activity and Ultrasensitive Glucose Sensing

Area of Science:

• Nanotechnology
• Catalysis
• Materials Science

Background:

• Artificial nanoreactors with embedded catalytic centers are crucial for chemical transformations.
• Achieving uniform distribution and accessible surfaces of catalysts within confined spaces is difficult.

Purpose of the Study:

• To develop a method for in situ synthesis of gold nanoparticles (Au NPs) within quantum dot (QD)-embedded coacervate droplets (QD-Ds).
• To investigate the catalytic properties and stability of these hybrid nanostructures.
• To demonstrate their application in biosensing.

Main Methods:

• In situ synthesis of Au NPs within QD-Ds without external reducing agents.
• High-resolution transmission electron microscopy (HR-TEM) for characterization.
• Peroxidase-like activity assays.
• Michaelis-Menten kinetics analysis.
• Cascade reaction for colorimetric glucose detection.

Main Results:

• Homogeneously distributed, stable Au NPs (5.6 ± 0.2 nm) were synthesized inside QD-Ds (Au@QD-Ds).
• QD surface carboxylic acid groups acted as reducing and stabilizing agents.
• Au@QD-Ds exhibited superior peroxidase-like activity compared to controls.
• Enhanced activity attributed to confinement, mass action, and ligand-free surfaces.
• Successful colorimetric glucose detection with a limit of detection of 272 nM.

Conclusions:

• A facile and robust method for fabricating hybrid plexcitonic assemblies was established.
• The Au@QD-Ds show excellent catalytic performance and recyclability.
• This approach holds potential for bioanalytical chemistry and optoelectronics.