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Catalytic mesoporous Janus nanomotors for active cargo delivery.

Ma X, Hahn K, Sanchez S - J. Am. Chem. Soc. (2015)

Bottom Line: The chemically powered Janus nanomotors present active diffusion at low H2O2 fuel concentration (i.e., <3 wt %).Their apparent diffusion coefficient is enhanced up to 100% compared to their Brownian motion.Due to their mesoporous architecture and small dimensions, they can load cargo molecules in large quantity and serve as active nanocarriers for directed cargo delivery on a chip.

View Article: PubMed Central - PubMed

Affiliation: †Max Planck Institute for Intelligent Systems Institution, Heisenbergstraße 3, 70569 Stuttgart, Germany.

ABSTRACT
We report on the synergy between catalytic propulsion and mesoporous silica nanoparticles (MSNPs) for the design of Janus nanomotors as active cargo delivery systems with sizes <100 nm (40, 65, and 90 nm). The Janus asymmetry of the nanomotors is given by electron beam (e-beam) deposition of a very thin platinum (2 nm) layer on MSNPs. The chemically powered Janus nanomotors present active diffusion at low H2O2 fuel concentration (i.e., <3 wt %). Their apparent diffusion coefficient is enhanced up to 100% compared to their Brownian motion. Due to their mesoporous architecture and small dimensions, they can load cargo molecules in large quantity and serve as active nanocarriers for directed cargo delivery on a chip.

No MeSH data available.


Related in: MedlinePlus

Optical video analysis on catalytic nanomotorof JMSNP(90 nm)-Pt(2nm). (a) Trajectory tracking of the catalytic JMSNM with differentH2O2 concentrations up to 30 s, (b) fittingplots of mean square displacement (MSD) versus time interval (Δt), analyzed from the trajectory tracking in (a), (c) apparentdiffusion coefficient values, determined by equation MSD = 4·D·Δt, and (d) optical videosnapshots extracted from optical videos in the SI of the JMSNM with 3% H2O2.
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fig3: Optical video analysis on catalytic nanomotorof JMSNP(90 nm)-Pt(2nm). (a) Trajectory tracking of the catalytic JMSNM with differentH2O2 concentrations up to 30 s, (b) fittingplots of mean square displacement (MSD) versus time interval (Δt), analyzed from the trajectory tracking in (a), (c) apparentdiffusion coefficient values, determined by equation MSD = 4·D·Δt, and (d) optical videosnapshots extracted from optical videos in the SI of the JMSNM with 3% H2O2.

Mentions: Diffusionof bare MSNPs showed no enhancement with increasing H2O2 concentration (0–6%) (Figure 2c), and no right shift was observed in the diffusioncoefficient distribution curves (Figure S5a–c in the SI). To further prove the catalytic activityof the Pt layer, a JMSNP with similar weight and composition was fabricatedas a negative control, by depositing catalytically inert element gold(Au) onto MSNP(65 nm) (Figure S6 in the SI). As expected, the apparent diffusion coefficient of JMSNP(65 nm)-Au(2nm) did not increase (Figure 2d) and no rightshift in the diffusion coefficient distribution curves was observed(Figure S5d in the SI). Furthermore, toconfirm the self-propelling phenomenon of JMSNM, the diffusion activityof the JMSNM was directly observed by optical microscopy. JMSNM(90nm) was chosen for microscopy observation because of the challengeto trace smaller nanoparticles in a reliable manner by optical microscopy.The trajectory of JMSNM was tracked by software ImageJ and plottedin Figure 3a. The movement of the nanomotorsexhibited a typical “random walk”. However, with thepresence of H2O2, the area covered by the nanomotors’“walk path” is much larger than without H2O2 (i.e., Brownian motion), suggesting enhanced diffusionof the JMSNM (Figure 3a, videos S1 and S2 inthe SI).


Catalytic mesoporous Janus nanomotors for active cargo delivery.

Ma X, Hahn K, Sanchez S - J. Am. Chem. Soc. (2015)

Optical video analysis on catalytic nanomotorof JMSNP(90 nm)-Pt(2nm). (a) Trajectory tracking of the catalytic JMSNM with differentH2O2 concentrations up to 30 s, (b) fittingplots of mean square displacement (MSD) versus time interval (Δt), analyzed from the trajectory tracking in (a), (c) apparentdiffusion coefficient values, determined by equation MSD = 4·D·Δt, and (d) optical videosnapshots extracted from optical videos in the SI of the JMSNM with 3% H2O2.
© Copyright Policy
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4440854&req=5

fig3: Optical video analysis on catalytic nanomotorof JMSNP(90 nm)-Pt(2nm). (a) Trajectory tracking of the catalytic JMSNM with differentH2O2 concentrations up to 30 s, (b) fittingplots of mean square displacement (MSD) versus time interval (Δt), analyzed from the trajectory tracking in (a), (c) apparentdiffusion coefficient values, determined by equation MSD = 4·D·Δt, and (d) optical videosnapshots extracted from optical videos in the SI of the JMSNM with 3% H2O2.
Mentions: Diffusionof bare MSNPs showed no enhancement with increasing H2O2 concentration (0–6%) (Figure 2c), and no right shift was observed in the diffusioncoefficient distribution curves (Figure S5a–c in the SI). To further prove the catalytic activityof the Pt layer, a JMSNP with similar weight and composition was fabricatedas a negative control, by depositing catalytically inert element gold(Au) onto MSNP(65 nm) (Figure S6 in the SI). As expected, the apparent diffusion coefficient of JMSNP(65 nm)-Au(2nm) did not increase (Figure 2d) and no rightshift in the diffusion coefficient distribution curves was observed(Figure S5d in the SI). Furthermore, toconfirm the self-propelling phenomenon of JMSNM, the diffusion activityof the JMSNM was directly observed by optical microscopy. JMSNM(90nm) was chosen for microscopy observation because of the challengeto trace smaller nanoparticles in a reliable manner by optical microscopy.The trajectory of JMSNM was tracked by software ImageJ and plottedin Figure 3a. The movement of the nanomotorsexhibited a typical “random walk”. However, with thepresence of H2O2, the area covered by the nanomotors’“walk path” is much larger than without H2O2 (i.e., Brownian motion), suggesting enhanced diffusionof the JMSNM (Figure 3a, videos S1 and S2 inthe SI).

Bottom Line: The chemically powered Janus nanomotors present active diffusion at low H2O2 fuel concentration (i.e., <3 wt %).Their apparent diffusion coefficient is enhanced up to 100% compared to their Brownian motion.Due to their mesoporous architecture and small dimensions, they can load cargo molecules in large quantity and serve as active nanocarriers for directed cargo delivery on a chip.

View Article: PubMed Central - PubMed

Affiliation: †Max Planck Institute for Intelligent Systems Institution, Heisenbergstraße 3, 70569 Stuttgart, Germany.

ABSTRACT
We report on the synergy between catalytic propulsion and mesoporous silica nanoparticles (MSNPs) for the design of Janus nanomotors as active cargo delivery systems with sizes <100 nm (40, 65, and 90 nm). The Janus asymmetry of the nanomotors is given by electron beam (e-beam) deposition of a very thin platinum (2 nm) layer on MSNPs. The chemically powered Janus nanomotors present active diffusion at low H2O2 fuel concentration (i.e., <3 wt %). Their apparent diffusion coefficient is enhanced up to 100% compared to their Brownian motion. Due to their mesoporous architecture and small dimensions, they can load cargo molecules in large quantity and serve as active nanocarriers for directed cargo delivery on a chip.

No MeSH data available.


Related in: MedlinePlus