Interfacial Superassembly of Light-Responsive Mechanism-Switchable Nanomotors with Tunable Mobility and Directionality

Abstract

Mechanism-switchable nanomotors are expected to exhibit high adaptability and wide applicability. Herein, for the first time, we report a flask-shaped carbon@Pt@fatty-acid nanomotor with a light-induced switch between nonionic self-diffusiophoresis and bubble propulsion. This nanomotor is fabricated through superassembly of platinum nanoparticles on the surface of carbon nanobottles, and fatty acids are infused into the cavity of carbon nanobottles to serve as a light-sensitive switch. Such a nanomotor can be propelled via catalytic decomposition of H2O2 by platinum nanoparticles, exhibiting self-diffusiophoresis with opening-forward migration. Upon 980 nm laser irradiation, the fatty acids melt due to the photothermal effect and are released from the cavity, switching the dominant operational mechanism to bubble propulsion with bottom-forward migration. Compared with self-diffusiophoresis, bubble propulsion shows higher mobility and better directionality due to the hindered self-rotation. Simulation results further reveal that the confinement effect of the cavity, which facilitates the nucleation of nanobubbles, leads to the switch to bubble propulsion. This study offers an insight into the relationship between nanostructures, fundamental nanomotor operational mechanisms, and apparent propulsion performance, as well as provides a novel strategy for the regulation of movement, which is instructive for both the design and applications of nanomotors.

A Motor-Based Carbonaceous Nanocalabash Catalyst for Deep-Layered Bioorthogonal Chemistry

“…In addition, to reduce the amount of computation, the FEA simulations were performed in a stationary manner, which means that the CNC-Cu motor is supposed to be at a fixed position. However, the simulated results were only applicable in understanding the possible mechanisms of motion during the initial instant (within 100 ns), which resulted in the autonomous movement of the CNC-Cu. ,, Animations S1–S3 record the temperature distribution, fluid velocity distribution, and pressure distribution in a time-dependent manner during 100 ns, respectively. Figure displays the simulated main parameters highly correlated with the mechanism of motion at different time points.…”

Controlled propulsion of micro/nanomotors: operational mechanisms, motion manipulation and potential biomedical applications

“…181,182 Recently, Liu et al reported a light-responsive mechanism-switchable nanomotor with tunable directionality. 150 The nanomotor was composed of a carbon nanobottle framework with Pt nanoparticles assembled on the surface. The cavity of the carbon nanobottle was filled with solid fatty acids.…”

“…Therefore, it is more desired that the motion of MNMs can be regulated using biologically relevant stimuli, such as temperature, pH and redox potentials, which naturally exist in human bodies. 150,151 For example, the oxygen concentration in tumor sites is lower than that in normal tissues due to the rapid proliferation of cancer cells; the pH in tumor sites is mildly acidic (o6.5), while the pH in normal tissues is nearly neutral (E7.5); the tumor cells show a higher concentration of H 2 O 2 compared to normal cells. It is also observed that the pH difference, as well as the redox potential difference, exists between the extracellular and intracellular microenvironments.…”

NIR light‐propelled bullet‐shaped carbon hollow nanomotors with controllable shell thickness for the enhanced dye removal

“…The materials with asymmetric nanostructures have attracted tremendous attention in various application fields in recent years. [1][2][3][4][5] A variety of asymmetric architectures have been created, such as bowl-liked, [6][7][8][9][10] bottle-shaped, [11][12][13][14][15] yolkshell, [16][17][18][19][20] and others. [3,[21][22][23][24][25] In addition, the components of materials with asymmetric nanostructures mainly include silica, [26][27][28] carbon, and [29][30][31] metals.…”