Nanoconfined Microenvironment-Regulated Photochromic Kinetics in Gold Nanocluster-Based Photoswitching Fluorescent...

Area of Science:

• Nanotechnology
• Materials Science
• Photochemistry

Background:

• Photoswitchable fluorescent nanoparticles (PF NPs) are crucial for sensing, imaging, and anticounterfeiting.
• Understanding photochromic behavior on nanoscale surfaces is vital for designing effective PF NPs.
• The influence of nanoconfined microenvironments on PF NP photochromic properties is not well understood.

Purpose of the Study:

• To investigate the role of nanoconfined microenvironments in modulating the photochromic properties of PF NPs.
• To develop a strategy for rationally designing robust PF NPs with tunable photochromic behavior.
• To explore the potential of engineered PF NPs for advanced applications like cell imaging.

Main Methods:

• Fabrication of PF NPs using fluorescent gold nanoclusters and spiropyran.
• Modulation of the spiropyran microenvironment by incorporating stearyl triphenyl phosphonium (STPP) into lipid bilayers.
• Analysis of photochromic kinetics and molecular dynamics simulations to elucidate structure-property relationships.

Main Results:

• Increasing STPP content significantly altered the photochromic kinetics of spiropyran within PF NPs.
• A charge-confinement model was proposed to explain the observed modulation of photochromic properties.
• Molecular dynamics simulations confirmed STPP-induced changes in nanoconfinement and spiropyran dynamics.

Conclusions:

• Nanoconfined microenvironments play a critical role in regulating the photochromic properties of PF NPs.
• The developed strategy offers a pathway for designing advanced optical probes with tailored functionalities.
• Engineered PF NPs demonstrate potential as robust probes for biocompatible cell imaging applications.