During the fellowship, objective 1 was met without deviation, and objective 2 was slightly changed by using nicotinamide adenine dinucleotide (NAD+), an important cofactor in cells, as the electron acceptor for biomedical application of nanomotor in the future. Due to the influence of positively charged osmium complex (Os) on the self-assembly of block-copolymer, we developed a post-functionalization method to attach Os onto the nanomotors. In brief, for all the objectives, functionalized block copolymers were synthesized and assembled into a stomatocyte structure.
For objective 1 (WP1), PS II enriched thylakoid membrane fragments (PSII-BBY) were successfully extracted from spinach and encapsulated into the stomatocyte during the shape transforming of polymersome, and visible light (680 nm) was used to drive the water-oxidation reaction catalyzed by PS II for translational motion.
For objective 2 (WP2), nitrogen-doped graphitic carbon dots and amorphous carbon dots were prepared and immobilized onto stomatocyte, and visible light (450 nm) was used to drive the reduction of NAD+ catalyzed by co-immobilized rhodium complex (Rh) for directional movement. To study the rotation, we successfully engineered polymersomes into different shapes, including nanorods, discs, rod-modified stomatocytes, etc.
For objective 3 (WP3), a molecular probe comprising Os as the functional module, pyrene as the anchor, and PEG as the spacer is synthesized. By harnessing the non-covalent interaction between pyrene and PEG corona of the nanomotors, Os is efficiently loaded onto the surface of the nanomotors. The length of the PEG spacer is manipulated to optimize the electron transfer between reduction and oxidation reactions.
The results from WP3 are published by Nature Chemistry. The results from WP2 are in preparation. The results from WP1 and WP3 are in preparation. In terms of collaborative work, I was able to publish a preprint version of our research work on nanomotors with programmable positive and negative chemotaxis as the third author paper, and one paper was submitted to Nature Materials as the third author. All the publications resulting from this fellowship include references to the EU funding.
In terms of exploitation and dissemination, we built international collaboration with Prof. Dr. Michael L. Klein (National Academy of Sciences) and Prof. Dr. Vincenzo Carnevale from Temple University on understanding the loading mechanism of Os complex by molecular dynamics simulation. We built a collaboration with the Electron Microscopy Center of Utrecht University on characterizing the nanomotors. Apart from this, the results were also disseminated in conferences of sIMMposium, NWO CHAINS, and FMS Annual meeting. The results were also disseminated in “Supramolecular and Systems Chemistry Course” at Nijmegen by the supervisor.
In terms of outreach activities, I joined the ‘open house’ organized by the Faculty of Science, Radboud University. Presentation, demo experiment, and Lab tour were given to communicate the project results and research activities of the host with a general audience, including primary school students. Moreover, a website (
http://apsimproject.com/(öffnet in neuem Fenster)) and YouTube channels are built to communicate project activities to different audiences. The project results are also communicated with the Twitter accounts of the departments.
