Person: Vilela García, Diana
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First Name
Diana
Last Name
Vilela García
Affiliation
Universidad Complutense de Madrid
Faculty / Institute
Ciencias Químicas
Department
Química Analítica
Area
Química Analítica
Identifiers
17 results
Search Results
Now showing 1 - 10 of 17
Publication Sucrose-Responsive Intercommunicated Janus Nanoparticles Network(MDPI, 2021) Jimenez-Falcao, Sandra; Torres, Daniel; Martínez-Ruíz, Paloma; Vilela García, Diana; Martínez-Máñez, Ramón; Villalonga Santana, ReynaldoInspired by biological systems, the development of artificial nanoscale materials that communicate over a short distance is still at its early stages. This work shows a new example of a cooperating system with intercommunicated devices at the nanoscale. The system is based on the new sucrose-responsive Janus gold-mesoporous silica (Janus Au-MS) nanoparticles network with two enzyme-powered nanodevices. These nanodevices involve two enzymatic processes based on invertase and glucose oxidase, which are anchored on the Au surfaces of different Janus Au-MS nanoparticles, and N-acetyl-L-cysteine and [Ru(bpy)3]2+ loaded as chemical messengers, respectively. Sucrose acts as the INPUT, triggering the sequential delivery of two different cargoes through the enzymatic control. Nanoscale communication using abiotic nanodevices is a developing potential research field and may prompt several applications in different disciplines, such as nanomedicine.Publication Drug-Free Enzyme-Based Bactericidal Nanomotors against Pathogenic Bacteria(ACS, 2021-03-26) Vilela García, Diana; Blanco Cabra, Nuria; Eguskiza, Ander; Hortelao, Ana C.; Torrents, Eduard; Sánchez, SamuelThe low efficacy of current conventional treatments for bacterial infections increases mortality rates worldwide. To alleviate this global health problem, we propose drug-free enzymebased nanomotors for the treatment of bacterial urinary-tract infections. We develop nanomotors consisting of mesoporous silica nanoparticles (MSNPs) that were functionalized with either urease (U-MSNPs), lysozyme (L-MSNPs), or urease and lysozyme (MMSNPs), and use them against nonpathogenic planktonic Escherichia coli. U-MSNPs exhibited the highest bactericidal activity due to biocatalysis of urea into NaHCO3 and NH3, which also propels U-MSNPs. In addition, U-MSNPs in concentrations above 200 μg/mL were capable of successfully reducing 60% of the biofilm biomass of a uropathogenic E. coli strain. This study thus provides a proof-of-concept, demonstrating that enzyme-based nanomotors are capable of fighting infectious diseases. This approach could potentially be extended to other kinds of diseases by selecting appropriate biomolecules.Publication Mentoría pedagógica como método de formación del profesorado universitario. Experiencia en la asignatura "Química Analítica I" del grado en Química(2023-07-17) Sánchez Sánchez, Alfredo; Villalonga Santana, Reynaldo; Urraca Ruiz, Javier; Gracia Lor, Emma; Vilela García, Diana; Rodríguez Bencomo, Juan José; Molla Escudero, David; Mayol Hornero, Beatriz; Villalonga Chico, AnabelPublication Supramolecular Enzymatic Labeling for Aptamer Switch-Based Electrochemical Biosensor(MDPI, 2022) Villalonga Chico, Anabel; Parrado Quintela, Concepción; Diaz, Raúl; Sánchez Sánchez, Alfredo; Mayol Hornero, Beatriz; Martínez-Ruíz, Paloma; Vilela García, Diana; Villalonga Santana, ReynaldoHere we report a novel labeling strategy for electrochemical aptasensors based on enzymatic marking via supramolecular host–guest interactions. This approach relies on the use of an adamantane-modified target-responsive hairpin DNA aptamer as an affinity bioreceptor, and a neoglycoconjugate of β-cyclodextin (CD) covalently attached to a redox enzyme as a labeling element. As a proof of concept, an amperometric aptasensor for a carcinoembryonic antigen was assembled on screen-printed carbon electrodes modified with electrodeposited fern-like gold nanoparticles/graphene oxide and, by using a horseradish peroxidase-CD neoglycoenzyme as a biocatalytic redox label. This aptasensor was able to detect the biomarker in the concentration range from 10 pg/mL to 1 ng/mL with a high selectivity and a low detection limit of 3.1 pg/mL in human serum samples.Publication High NIR-purity index single-walled carbon nanotubes for electrochemical sensing in microfluidic chips(The Royal Society of Chemistry, 2012-03-23) Vilela García, Diana; Ansón-Casaos, Alejandro; Martínez, María Teresa; González, María Cristina; Escarpa, AlbertoSingle-walled carbon nanotubes (SWCNTs) should constitute an important natural step towards the improvement of the analytical performance of microfluidic electrochemical sensing. SWCNTs inherently offer lower detection potentials, higher surfaces and better stability than the existing carbon electrodes. However, pristine SWCNTs contain some carbonaceous and metallic impurities that influence their electrochemical performance. Thus, an appropriate processing method is important for obtaining high purity SWCNTs for analytical applications. In this work, a set of 0.1 mg mL−1 SWCNT dispersions with different degrees of purity and different dispersants (SDBS; pluronic F68 and DMF) was carefully characterized by near infrared (NIR) spectroscopy giving a Purity Index (NIR-PI) ranging from 0.039 to 0.310. The highest purity was obtained when air oxidized SWCNTs were dispersed in SDBS, followed by centrifugation. The SWCNT dispersions were utilized to modify microfluidic chip electrodes for the electrochemical sensing of dopamine and catechol. In comparison with non-SWCNT-based electrodes, the sample with the highest NIR-PI (0.310) exhibited the best analytical performance in terms of improved sensitivity (3-folds higher), very good signal-to-noise ratio, high resistance-to-fouling in terms of relative standard deviation (RSD 7%; n = 15), and enhanced resolution (2-folds higher). In addition, very well-defined concentration dependence was also obtained with excellent correlation coefficients (r ≥ 0.990). Likewise, a good analytical sensitivity, suitable detection limits (LODs) and a very good precision with independence of the concentration assayed (RSDs ≤ 5%) was achieved. These valuable features indicate the suitability of this material for quantitative analysis. NIR-PI and further TEM and XRD characterization demonstrated that the analytical response was driven and controlled by the high NIR-PI of the SWCNTs used. The significance of this work is the demonstration for the first time of the sensitivity–purity relationship in SWCNT microfluidic chips. A novel and valuable analytical tool for electrochemical sensing has been developed: SWCNTs with high purity and a rich surface chemistry with functional groups, both essential for analytical purposes. Also, this work helps to better understand the analytical potency of SWCNTs coupled to microfluidic chips and it opens new gates for using these unique dispersions in real-world applications.Publication Gold-nanosphere formation using food sample endogenous polyphenols for in-vitro assessment of antioxidant capacity(Springer Nature, 2012-05-22) Vilela, Diana; González, María Cristina; Escarpa, Alberto; Vilela García, DianaIn this work it was demonstrated that sample endogenous polyphenols are selectively driving the gold-nanoparticle (AuNPs)-formation process when representative food samples were used as natural sources of reducing compounds. The process of AuNPs formation was characterized by UV–visible spectroscopy and was described by a sigmoidal curve (R 2 ≥ 0.990) which gave information about the polyphenol concentration at which the localized surface plasmon resonance (LSPR) absorption reached its half-value, X50c, and about AuNPs production per polyphenol concentration unit, K AuNPs. The behavior of phenolic acids was different, with lower X 50c and higher K AuNPs values than flavonoids. For the food samples tea, apple, pear, wine, and honey X50c values were 0.22, 7.3, 11.5, 20.4, 30.3, and 53.5 (mg mL−1) and K AuNPs values were 28.7, 0.70, 0.60, 0.20, 0.14, and 0.10 (mg−1 mL), respectively. Excellent correlation between K AuNPs and total phenolics (TP) was obtained (r = 0.98, p-value < 0.05), implying K AuNPs is a novel marker for evaluation of food sample antioxidant capacity in vitro. The K AuNPs values of samples indicated their antioxidant capacity was in the order: tea > apple > pear > wine > honey. The reproducibility of the AuNPs formation approach was excellent, not only for polyphenol standards (RSD < 6 % for X50c and RSD < 11 % for K AuNPs) but also for food samples (RSD < 9 % for X50c and RSD < 15 % for K AuNPs). Transmission electronic microscopy (TEM) enabled confirmation of the formation of stabilized Au-nanospheres from endogenous polyphenols with very well-defined sizes under 20 nm diameter for all the food samples investigated.Publication Antioxidant capacity index based on gold nanoparticles formation. Application to extra virgin olive oil samples(ElSevier, 2015-07-01) Della Pelle, Flavio; Vilela, Diana; González, María Cristina; Lo Sterzo, Claudio; Compagnone, Darío; Carlo, Michele Del; Escarpa, Alberto; Vilela García, DianaA simple gold nanoparticles (AuNPs) based colorimetric assay for the antioxidant activity determination has been developed. The AuNP formation is mediated by extra virgin olive oil (EVOO’s) endogenous polyphenols; the reaction is described by a sigmoidal curve. The ratio KAuNPs/Xc50 (slope of the linear part of the sigmoid/concentration at half value of the absorbance) was found to be the optimal parameter to report the antioxidant capacity with respect to the single KAuNPs or Xc50 values. The obtained data demonstrated that the compounds with ortho-diphenols functionality are most active in reducing gold (III) to gold (0). Thus, intermediate activity was found for gallic acid, while tyrosol (mono-phenols) had a significant lower activity than the others antioxidant compounds (at least one order of magnitude). In the analysis of olive oil samples, a significant correlation among classical methods used to determine antioxidant activity and the proposed parameter was found with R values in the 0.96–0.97 range.Publication A glutathione disulfide-sensitive Janus nanomachine controlled by an enzymatic and logic gate for smart delivery(The Royal Society of Chemistry, 2021-09-29) Mayol Hornero, Beatriz; Díez-Sánchez, Paula; Sánchez Sánchez, Alfredo; Torre, Cristina de la; Villalonga, Anabel; Lucena-Sánchez, Elena; Sancenón, Félix; Martínez Ruiz, María Paloma; Vilela García, Diana; Martínez-Máñez, Ramón; Villalonga Santana, ReynaldoThis work describes the assembly of a novel enzyme-controlled nanomachine operated through an AND Boolean logic gate for on-command delivery. The nanodevice was constructed on Au-mesoporous silica Janus nanoparticles capped with a thiol-sensitive gate-like molecular ensemble on the mesoporous face and functionalized with glutathione reductase on the gold face. This autonomous nanomachine employed NADPH and glutathione disulfide as input chemical signals, leading to the enzymatic production of reduced glutathione that causes the disruption of the gating mechanism on the mesoporous face and the consequent payload release as an output signal. The nanodevice was successfully used for the autonomous release of doxorubicin in HeLa cancer cells and RAW 264.7 macrophage cells.Publication Micromotor‐in‐Sponge Platform for Multicycle Large‐Volume Degradation of Organic Pollutants(Wiley, 2022-05-01) Vilela García, Diana; Maria Guix; Jemish Parmar; Àngel Blanco‐Blanes; Samuel SánchezThe presence of organic pollutants in the environment is a global threat to human health and ecosystems due to their bioaccumulation and long‐term persistence. Hereby a micromotor‐in‐sponge concept is presented that aims not only at pollutant removal, but towards an efficient in situ degradation by exploiting the synergy between the sponge hydrophobic nature and the rapid pollutant degradation promoted by the cobalt‐ferrite (CFO) micromotors embedded at the sponge's core. Such a platform allows the use of extremely low fuel concentration (0.13% H2O2), as well as its reusability and easy recovery. Moreover, the authors demonstrate an efficient multicycle pollutant degradation and treatment of large volumes (1 L in 15 min) by using multiple sponges. Such a fast degradation process is due to the CFO bubble‐propulsion motion mechanism, which induces both an enhanced fluid mixing within the sponge and an outward flow that allows a rapid fluid exchange. Also, the magnetic control of the system is demonstrated, guiding the sponge position during the degradation process. The micromotor‐in‐sponge configuration can be extrapolated to other catalytic micromotors, establishing an alternative platform for an easier implementation and recovery of micromotors in real environmental applications.Publication Magnetotactic Bacteria Powered Biohybrids Target E. coli Biofilms(American Chemical Society (ACS), 2017-09-21) Stanton, Morgan M.; Park, Byung-Wook; Bente, Klaas; Faivre, Damien; Sitti, Metin; Sánchez, Samuel; Vilela García, DianaBiofilm colonies are typically resistant to general antibiotic treatment and require targeted methods for their removal. One of these methods includes 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 nonpathogenic magnetotactic bacteria Magnetosopirrillum gryphiswalense (MSR-1) can be integrated with drug-loaded mesoporous silica microtubes 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, is triggered by the acidic microenvironment of the biofilm, ensuring an efficient drug delivery system. The results reveal the capabilities of a nonpathogenic bacteria species to target and dismantle harmful biofilms, indicating biohybrid systems have great potential for antibiofilm applications.