Unveiling the photoluminescence dynamics of gold nanoclusters with fluorescence correlation spectroscopy.
Malavika Kayyil VeeduJulia OsmólskaAgata HajdaJoanna Olesiak-BanskaJérôme WengerPublished in: Nanoscale advances (2023)
Gold nanoclusters (AuNCs) have captured significant interest for their photoluminescent properties; however, their rapid photodynamics remain elusive while probed by ensemble-averaging spectroscopy techniques. To address this challenge, we use fluorescence correlation spectroscopy (FCS) to uncover the photoluminescence dynamics of colloidal Au 18 (SG) 14 nanoclusters. Our FCS analysis reveals the photoluminescence (PL) brightness per nanocluster, elucidating the impact of photoexcitation saturation and ligand interactions. Unlike DNA-encapsulated silver nanoclusters, their gold counterparts notably exhibit minimal blinking, with moderate amplitudes and 200 μs characteristic times. Our data also clearly reveal the occurrence of photon antibunching in the PL emission, showcasing the quantum nature of the PL process, with each AuNC acting as an individual quantum source. Using zero-mode waveguide nanoapertures, we achieve a 16-fold enhancement of the PL brightness of individual AuNCs. This constitutes an important enabling proof-of-concept for tailoring emission properties through nanophotonics. Overall, our study bridges the gap between ensemble-averaged techniques and single-molecule spectroscopy, offering new insights into AuNC photodynamics for biosensing and imaging applications.
Keyphrases
- single molecule
- energy transfer
- quantum dots
- sensitive detection
- living cells
- atomic force microscopy
- high resolution
- label free
- silver nanoparticles
- solid state
- fluorescent probe
- risk assessment
- gold nanoparticles
- molecular dynamics
- electronic health record
- loop mediated isothermal amplification
- convolutional neural network
- molecular dynamics simulations
- dna methylation
- mass spectrometry
- neural network
- artificial intelligence
- fluorescence imaging