Insight into Sonoluminescence Augmented by ZnO-Functionalized Nanoparticles

Abstract

Recent advances in optical imaging techniques rely on the use of nanosized contrast agents for in vitro and in vivo applications. We report on an imaging method based on the inertial cavitation of ultrasound-irradiated water solutions that lead to sonoluminescence (SL), here, newly proposed in combination with semiconductor nanoparticles, in particular, aminopropyl-functionalized zinc oxide nanocrystals. The obtained measurements confirm the ability of such nanocrystals to increase the sonoluminescence emission, together with the ability to modify the SL spectrum when compared to the pure water behavior. In particular, it is shown that the UV component of SL is absorbed by the semiconductor behavior that is also confirmed in different biologically relevant media. Finally, optical images of nanocrystal-assisted SL are acquired for the first time, in particular, in biological buffers, revealing that at low ultrasound intensities, SL is measurable only when the nanocrystals are present in solution. All of these results witness the role of amine-functionalized zinc oxide nanocrystals for sonoluminescence emission, which makes them very good candidates as efficient nanocontrast agents for SL imaging for biological and biomedical applications.

Biomechanical Sensing Using Gas Bubbles Oscillations in Liquids and Adjacent Technologies: Theory and Practical Applications

“…In many electrochemical and photo-electrochemical processes individual H , N and O bubbles are generated as a result of electrocatalytic reactions on the surface of disc electrodes immersed in an aqueous solution of sulfuric acid [ 240 ]. Bubbles can also be electrogenerated in nonaqueous media such as methanol, ethanol, ethylene glycol, acetone and other solvents [ 240 ]. An extended discussion of these methods can be found in [ 241 ].…”

“…Although the intensity of sonoluminescence is rather low compared to that used in the well-established optical sensing methods such as fluorescence spectroscopy, it has been argued that the light emitted by collapsing bubbles can be exploited to non-invasively photo-activate drugs inside a living body or a biological cell [ 244 ]. Moreover, recent studies [ 33 , 240 , 241 ] proposed several novel approaches to further enhance sonoluminescence light intensity to a level detectable by standard equipment. In particular, the presence of nanoparticles, which does not affect the acoustic properties of a bubble, amplifies sonoluminescence by fluorescence-like [ 240 , 241 ] and plasmonic [ 33 ] effects.…”

“…Moreover, recent studies [ 33 , 240 , 241 ] proposed several novel approaches to further enhance sonoluminescence light intensity to a level detectable by standard equipment. In particular, the presence of nanoparticles, which does not affect the acoustic properties of a bubble, amplifies sonoluminescence by fluorescence-like [ 240 , 241 ] and plasmonic [ 33 ] effects.…”

Biomechanical Sensing using Gas Bubbles Oscillations in Liquids and Adjacent Technologies: Theory and Practical Applications

“…An acoustic pressure wave with the frequency and peak amplitude that are similar 1000 to those of ultrasound waves used in medical ultrasound procedures drives bubble drugs inside a living body or a biological cell [239]. Moreover, recent works [24,240,241] 1026 proposed several novel approaches to further enhancement of sonoluminescence light 1027 intensity to a level detectable by standard equipment. In particular, the presence of 1028 nanoparticles, which does not affect acoustic properties of a bubble, amplifies sonolumi-1029 nescence by fluorescence-like [240,241] and plasmonic [24] effects.…”

“…Moreover, recent works [24,240,241] 1026 proposed several novel approaches to further enhancement of sonoluminescence light 1027 intensity to a level detectable by standard equipment. In particular, the presence of 1028 nanoparticles, which does not affect acoustic properties of a bubble, amplifies sonolumi-1029 nescence by fluorescence-like [240,241] and plasmonic [24] effects.…”