48 research outputs found
Formation and dissolution of microbubbles on highly-ordered plasmonic nanopillar arrays
Bubble formation from plasmonic heating of nanostructures is of great interest in many applications. In this work, we study experimentally the intrinsic effects of the number of three-dimensional plasmonic nanostructures on the dynamics of microbubbles, largely decoupled from the effects of dissolved air. The formation and dissolution of microbubbles is observed on exciting groups of 1, 4, and 9 nanopillars. Our results show that the power threshold for the bubble formation depends on the number density of the nanopillars in highly-ordered arrays. In the degassed water, both the growth rate and the maximal radius of the plasmonic microbubbles increase with an increase of the illuminated pillar number, due to the heat balance between the heat loss across the bubble and the collective heating generated from the nanopillars. Interestingly, our results show that the bubble dissolution is affected by the spatial arrangement of the underlying nanopillars, due to the pinning effect on the bubble boundary. The bubbles on nanopillar arrays dissolve in a jumping mode with step-wise features on the dissolution curves, prior to a smooth dissolution phase for the bubble pinned by a single pillar. The insight from this work may facilitate the design of nanostructures for efficient energy conversion
Hybrid plasmonic nanostructures based on controlled integration of MoS2 flakes on metallic nanoholes
Here, we propose an easy and robust strategy for the versatile preparation of
hybrid plasmonic nanopores by means of controlled deposition of single flakes
of MoS2 directly on top of metallic holes. The device is realized on silicon
nitride commercial membranes and can be further refined by TEM or FIB milling
to achieve the passing of molecules or nanometric particles through a pore.
Importantly, we show that the plasmonic enhancement provided by the nanohole is
strongly accumulated in the 2D nanopore, thus representing an ideal system for
single-molecule sensing and sequencing in a flow-through configuration. Here,
we also demonstrate that the prepared 2D material can be decorated with
metallic nanoparticles that can couple their resonance with the nanopore
resonance to further enhance the electromagnetic field confinement at the
nanoscale level. This method can be applied to any gold nanopore with a high
level of reproducibility and parallelization; hence, it can pave the way to the
next generation of solid-state nanopores with plasmonic functionalities.
Moreover, the controlled/ordered integration of 2D materials on plasmonic
nanostructures opens a pathway towards new investigation of the following:
enhanced light emission; strong coupling from plasmonic hybrid structures; hot
electron generation; and sensors in general based on 2D materials. Nanopor
3d plasmonic nanoantennas integrated with mea biosensors
Plasmonic 3D nanoantennas are integrated on multielectrode arrays. These biosensors can record extracellular activity and enhance Raman signals from living neurons
Spatially, Temporally, and Quantitatively Controlled Delivery of Broad Range of Molecules into Selected Cells through Plasmonic Nanotubes
A Universal plasmonic/microfluidic platform for spatial and temporal controlled intracellular delivery is described. The system can inject/transfect the desired amount of molecules with an efficacy close to 100%. Moreover, it is highly scalable from single cells to large ensembles without administering the molecules to an extracellular bath. The latter enables quantitative control over the amount of injected molecules
Hybrid plasmonic nanostructures based on controlled integration of MoS2 flakes on metallic nanoholes
Here, we propose an easy and robust strategy for the versatile preparation of hybrid plasmonic nanopores by means of controlled deposition of single flakes of MoS2 directly on top of metallic holes. The device is realized on silicon nitride membranes and can be further refined by TEM or FIB milling to achieve the passing of molecules or nanometric particles through a pore. Importantly, we show that the plasmonic enhancement provided by the nanohole is strongly accumulated in the 2D nanopore, thus representing an ideal system for single-molecule sensing and sequencing in a flow-through configuration. Here, we also demonstrate that the prepared 2D material can be decorated with metallic nanoparticles that can couple their resonance with the nanopore resonance to further enhance the electromagnetic field confinement at the nanoscale level. This method can be applied to any gold nanopore with a high level of reproducibility and parallelization; hence, it can pave the way to the next generation of solid-state nanopores with plasmonic functionalities. Moreover, the controlled/ordered integration of 2D materials on plasmonic nanostructures opens a pathway towards new investigation of the following: enhanced light emission; strong coupling from plasmonic hybrid structures; hot electron generation; and sensors in general based on 2D materials
Site-Selective Integration of MoS2 Flakes on Nanopores by Means of Electrophoretic Deposition
Here, we propose an easy method for site-selective deposition of two-dimensional (2D) material
flakes onto nanoholes by means of electrophoretic deposition. This method can be applied to both simple flat nanostructures and complex three-dimensional structures incorporating nano-
holes. The deposition method is here used for the decoration of large ordered arrays of plasmonic structures with either a single or few layers of MoS2 . In principle, the plasmonic
field generated by the nanohole can significantly interact with the 2D layer leading to enhanced light−material interaction. This makes our platform an ideal system for hybrid 2D material/
plasmonic investigations. The engineered deposition of 2D materials on plasmonic nanostructures is useful for several important applications such as enhanced light emission, strong coupling, hot-electron generation, and 2D material sensors. Site-selective integration of MoS2 flakes on nanopores by means of electrophoretic deposition
Enhanced Raman Investigation of Cell Membrane and Intracellular Compounds by 3D Plasmonic Nanoelectrode Arrays
3D nanostructures are widely exploited in cell cultures for many purposes such as controlled drug delivery, transfection, intracellular sampling, and electrical recording. However, little is known about the interaction of the cells with these substrates, and even less about the effects of electroporation on the cellular membrane and the nuclear envelope. This work exploits 3D plasmonic nanoelectrodes to study, by surface-enhanced Raman scattering (SERS), the cell membrane dynamics on the nanostructured substrate before, during, and after electroporation. In vitro cultured cells tightly adhere on 3D plasmonic nanoelectrodes precisely in the plasmonic hot spots, making this kind of investigation possible. After electroporation, the cell membrane dynamics are studied by recording the Raman time traces of biomolecules in contact or next to the 3D plasmonic nanoelectrode. During this process, the 3D plasmonic nanoelectrodes are intracellularly coupled, thus enabling the monitoring of different molecular species, including lipids, proteins, and nucleic acids. Scanning electron microscopy cross-section analysis evidences the possibility of nuclear membrane poration compatible with the reported Raman spectra. These findings may open a new route toward controlled intracellular sampling and intranuclear delivery of genic materials. They also show the possibility of nuclear envelope disruption which may lead to negative side effects