Plasmonic Nanobubbles in “Armored” Surface Nanodroplets

Abstract

Plasmonic nanobubbles are bubbles that are formed from local heat generated by noble metal nanoparticles under illumination of light at resonance. Understanding the formation and behavior of plasmonic nanobubbles is important for a broad suite of applications that rely on enhanced local heating of nanoparticles, such as in biomedical treatments and solar energy conversion. Here, we investigate formation, growth, and dissolution of plasmonic bubbles in a model system of oil nanodroplets in water. Gold nanoparticles were located at the surface of nanodroplets immobilized on a substrate. We followed temporal evolution of plasmonic nanobubbles from ∼200 nm in radius and above. Our experimental results show that there is an upper limit of the bubble size set by hosting droplet size, beyond which the nanobubbles burst. Nanobubbles grew, following the same growth exponent that was reported for a sub-millimeter bubble in contact with a bulk organic solvent. When the laser was switched off, the nanobubbles could remain for several minutes, much longer than the bubbles formed directly in water. The findings from this work may be valuable for light-driven chemical conversion in droplets or photothermal treatments involving immiscible phases.

Plasmonic Microbubble Dynamics in Binary Liquids

“… 10 The bubble dynamics in these different phases depends on several factors, such as particle arrangement, 7 laser power, gas concentration, 10 − 12 and types of liquid. 13 , 14 The nucleation of a giant bubble is initiated by locally heating the liquid around the plasmonic particle up to the spinodal temperature. 10 The heating process is limited by thermal diffusion and can theoretically be described well.…”

Do Lipid-based Nanoparticles Hold Promise for Advancing the Clinical Translation of Anticancer Alkaloids?

“…To address this issue, a laser pulse-activated nanoevent, called the plasmonic nanobubble, was developed to provide real-time intraoperative in vivo detection of MRD to guide precise and selective surgical resection of MRD with minimal damage to adjacent normal tissues [60]. Plasmonic nanobubbles are bubbles generated when metallic nanostructures convert light energy into highly localized heat that overheats liquid in their proximity, leading to a liquid-vapor phase transition and formation of vapor nanobubbles [61]. While this innovative nanotechnology has yet to be tested clinically, this unique on-demand threshold-activated transient nanoevent offers a new avenue for investigation in other applications, including diagnostics, therapy and theranostics.…”

Nucleation and dynamics of bubbles/droplets in multicomponent liquids

“…In a previous study, we have shown that plasmonic microbubbles in pure (mono-component) liquids undergo four different phases: the initial giant vapor bubble (phase I), the oscillating bubble (phase II), the water vaporization dominated growth (phase III), and the air diffusion dominated growth (phase IV) [30]. The bubble dynamics in these different phases depends on several factors, such as particle arrangement [58], laser power, gas concentration [30,32,62], and types of liquid [31,141]. The nucleation of a giant bubble is initiated by locally heating the liquid around the plasmonic particle up to the spinodal temperature [30].…”

“…Most of these studies were conducted in water or other pure liquids [141], such as n-alkanes [31]. However, it is known that many plasmonic assisted processes also take place in binary liquids [21].…”