Staff member


Diana Vilela Garcia

Postdoctoral Researcher
Smart Nano-Bio-Devices
dvilela@ibecbarcelona.eu
+34 934 020 515
Staff member publications

Vilela, D., Stanton, M. M., Parmar, J., Sánchez, S., (2017). Microbots decorated with silver nanoparticles kill bacteria in aqueous media ACS Applied Materials and Interfaces 9, (27), 22093-22100

Water contamination is one of the most persistent problems of public health. Resistance of some pathogens to conventional disinfectants can require the combination of multiple disinfectants or increased disinfectant doses, which may produce harmful byproducts. Here, we describe an efficient method for disinfecting Escherichia coli and removing the bacteria from contaminated water using water self-propelled Janus microbots decorated with silver nanoparticles (AgNPs). The structure of a spherical Janus microbot consists of a magnesium (Mg) microparticle as a template that also functions as propulsion source by producing hydrogen bubbles when in contact with water, an inner iron (Fe) magnetic layer for their remote guidance and collection, and an outer AgNP-coated gold (Au) layer for bacterial adhesion and improving bactericidal properties. The active motion of microbots increases the chances of the contact of AgNPs on the microbot surface with bacteria, which provokes the selective Ag+ release in their cytoplasm, and the microbot self-propulsion increases the diffusion of the released Ag+ ions. In addition, the AgNP-coated Au cap of the microbots has a dual capability of capturing bacteria and then killing them. Thus, we have demonstrated that AgNP-coated Janus microbots are capable of efficiently killing more than 80% of E. coli compared with colloidal AgNPs that killed only less than 35% of E. coli in contaminated water solutions in 15 min. After capture and extermination of bacteria, magnetic properties of the cap allow collection of microbots from water along with the captured dead bacteria, leaving water with no biological contaminants. The presented biocompatible Janus microbots offer an encouraging method for rapid disinfection of water.

Keywords: Bactericidal, Magnetic control, Micromotors, Microswimmers, Self-propulsion, Silver nanoparticles


Vilela, D., Hortelao, A. C., Balderas-Xicohtencatl, R., Hirscher, M., Hahn, K., Ma, X., Sanchez, S., (2017). Facile fabrication of mesoporous silica micro-jets with multi-functionalities Nanoscale 9, 13990

Self-propelled micro/nano-devices have been proved as powerful tools in various applications given their capability of both autonomous motion and on-demand task fulfilment. Tubular micro-jets stand out as an important member in the family of self-propelled micro/nano-devices and are widely explored with respect to their fabrication and functionalization. A few methods are currently available for the fabrication of tubular micro-jets, nevertheless there is still a demand to explore the fabrication of tubular micro-jets made of versatile materials and with the capability of multi-functionalization. Here, we present a facile strategy for the fabrication of mesoporous silica micro-jets (MSMJs) for tubular micromotors which can carry out multiple tasks depending on their functionalities. The synthesis of MSMJs does not require the use of any equipment, making it facile and cost-effective for future practical use. The MSMJs can be modified inside, outside or both with different kinds of metal nanoparticles, which provide these micromotors with a possibility of additional properties, such as the anti-bacterial effect by silver nanoparticles, or biochemical sensing based on surface enhanced Raman scattering (SERS) by gold nanoparticles. Because of the high porosity, high surface area and also the easy surface chemistry process, the MSMJs can be employed for the efficient removal of heavy metals in contaminated water, as well as for the controlled and active drug delivery, as two proof-of-concept examples of environmental and biomedical applications, respectively. Therefore, taking into account the new, simple and cheap method of fabrication, highly porous structure, and multiple functionalities, the mesoporous silica based micro-jets can serve as efficient tools for desired applications.


Stanton, Morgan M., Park, Byung-Wook, Vilela, Diana, Bente, Klaas, Faivre, Damien, Sitti, Metin, Sanchez, Samuel, (2017). Magnetotactic bacteria powered biohybrids target E. coli biofilms ACS Nano Just Accepted Manuscript

Biofilm colonies are typically resistant to general antibiotic treatment and require targeted methods for their removal. One of these methods include the use of nanoparticles as carriers for antibiotic delivery, where they randomly circulate in fluid until they make contact with the infected areas. However, the required proximity of the particles to the biofilm results in only moderate efficacy. We demonstrate here that the non-pathogenic magnetotactic bacteria, Magnetosopirrillum gryphiswalense (MSR-1), can be integrated with drug-loaded mesoporous silica microtubes (MSMs) to build controllable microswimmers (biohybrids) capable of antibiotic delivery to target an infectious biofilm. Applying external magnetic guidance capability and swimming power of the MSR-1 cells, the biohybrids are directed to and forcefully pushed into matured Escherichia coli (E. coli) biofilms. Release of the antibiotic, ciprofloxacin (CFX), is triggered by the acidic microenvironment of the biofilm ensuring an efficient drug delivery system. The results reveal the capabilities of a non-pathogenic bacteria species to target and dismantle harmful biofilms, indicating biohybrid systems have great potential for anti-biofilm applications.


Vilela, Diana, Parmar, Jemish, Zeng, Yongfei, Zhao, Yanli, Sánchez, Samuel, (2016). Graphene based microbots for toxic heavy metal removal and recovery from water Nano Letters 16, (4), 2860-2866

Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nano-systems and nanomaterials for fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer and removal of a heavy metal -lead-, and its subsequent recovery for recycling purposes. Microbots? structure consists of nano-sized multilayers of graphene oxide, nickel and platinum which provide different functionalities. The outer layer of graphene oxide captures lead on the surface, the inner layer of platinum function as the engine decomposing hydrogen peroxide fuel for self-propulsion, whilst the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead ten times more efficiently than non-mobile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals. Heavy metal contamination in water is a serious risk to the public health and other life forms on earth. Current research in nanotechnology is developing new nano-systems and nanomaterials for fast and efficient removal of pollutants and heavy metals from water. Here, we report graphene oxide-based microbots (GOx-microbots) as active self-propelled systems for the capture, transfer and removal of a heavy metal -lead-, and its subsequent recovery for recycling purposes. Microbots? structure consists of nano-sized multilayers of graphene oxide, nickel and platinum which provide different functionalities. The outer layer of graphene oxide captures lead on the surface, the inner layer of platinum function as the engine decomposing hydrogen peroxide fuel for self-propulsion, whilst the middle layer of nickel enables external magnetic control of the microbots. Mobile GOx-microbots remove lead ten times more efficiently than non-mobile GOx-microbots, cleaning water from 1000 ppb down to below 50 ppb in 60 min. Furthermore, after chemical detachment of lead from the surface of GOx-microbots, the microbots can be reused. Finally, we demonstrate the magnetic control of the GOx-microbots inside a microfluidic system as a proof-of-concept for automatic microbots-based system to remove and recover heavy metals.


Parmar, J., Vilela, D., Pellicer, E., Esqué-de los Ojos, D., Sort, J., Sánchez, S., (2016). Reusable and long-lasting active microcleaners for heterogeneous water remediation Advanced Functional Materials 26, (23), 4152-4161

Self-powered micromachines are promising tools for future environmental remediation technology. Waste-water treatment and water reuse is an essential part of environmental sustainability. Herein, we present reusable Fe/Pt multi-functional active microcleaners that are capable of degrading organic pollutants (malachite green and 4-nitrophenol) by generated hydroxyl radicals via a Fenton-like reaction. Various different properties of microcleaners, such as the effect of their size, short-term storage, long-term storage, reusability, continuous swimming capability, surface composition, and mechanical properties, are studied. It is found that these microcleaners can continuously swim for more than 24 hours and can be stored more than 5 weeks during multiple cleaning cycles. The produced microcleaners can also be reused, which reduces the cost of the process. During the reuse cycles the outer iron surface of the Fe/Pt microcleaners generates the in-situ, heterogeneous Fenton catalyst and releases a low concentration of iron into the treated water, while the mechanical properties also appear to be improved due to both its surface composition and structural changes. The microcleaners are characterized by scanning electron microscopy (SEM), X-ray photoelectron spectroscopy (XPS), nanoindentation, and finite-element modeling (FEM).

Keywords: Catalysts, Heterogeneous catalysis, Microcleaners, Micromotors, Nanorobots, Wastewater treatment


Vilela, Diana, Romeo, Agostino, Sánchez, Samuel, (2016). Flexible sensors for biomedical technology Lab on a Chip 16, (3), 402-408

Flexible sensing devices have gained a great deal of attention among the scientific community in recent years. The application of flexible sensors spans over several fields, including medicine, industrial automation, robotics, security, and human-machine interfacing. In particular, non-invasive health-monitoring devices are expected to play a key role in the improvement of patient life and in reducing costs associated with clinical and biomedical diagnostic procedures. Here, we focus on recent advances achieved in flexible devices applied on the human skin for biomedical and healthcare purposes.


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