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Photothermal therapy (PTT) is a method for eradicating tumor tissues through the use of photothermal materials and photosensitizing agents that absorb light energy from laser sources and convert it into heat, which selectively targets and destroys cancer cells while sparing healthy tissue. MXenes have been intensively investigated as photosensitizing agents for PTT. However, achieving the selectivity of MXenes to the tumor cells remains a challenge. Specific antibodies (Ab) against tumor antigens can achieve homing of the photosensitizing agents toward tumor cells, but their immobilization on MXene received little attention. Here, we offer a strategy for the selective ablation of melanoma cells using MXene-polydopamine-antiCEACAM1 Ab complexes. We coated Ti3C2Tx MXene with polydopamine (PDA), a natural compound that attaches Ab to the MXene surface, followed by conjugation with an anti-CEACAM1 Ab. Our experiments confirm the biocompatibility of the Ti3C2Tx-PDA and Ti3C2Tx-PDA-antiCEACAM1 Ab complexes across various cell types. We also established a protocol for the selective ablation of CEACAM1-positive melanoma cells using near-infrared irradiation. The obtained complexes exhibit high selectivity and efficiency in targeting and eliminating CEACAM1-positive melanoma cells while sparing CEACAM1-negative cells. These results demonstrate the potential of MXene-PDA-Ab complexes for cancer therapy. They underline the critical role of targeted therapies in oncology, offering a promising avenue for the precise and safe treatment of melanoma and possibly other cancers characterized by specific biomarkers. Future research will aim to refine these complexes for clinical use, paving the way for new strategies for cancer treatment.
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In the rapidly evolving field of medical diagnostics, biomarkers play a pivotal role, particularly in the early detection of cancer. Cluster of differentiation 5 (CD5), a cell surface glycoprotein found on T cells and B-1a lymphocytes, is instrumental in immune regulation and is associated with both autoimmune diseases and malignancies. Despite its significant diagnostic and therapeutic potential, CD5 detection has been limited by modern methods in the pg/ml range. This study presents a novel multimodal electrochemical immunosensor that employs laser-processed Ti/Au electrodes for the ultra-sensitive detection of CD5 in human blood serum. The "multimodal" approach combines different analytical techniques - differential pulse volctammetry (DPV) and electrochemical impedance spectroscopy (EIS) - to ensure comprehensive analysis, enhancing both the accuracy and reliability of the sensor. This novel sensor significantly outperforms existing commercial ELISA kits, achieving a limit of detection (LOD) of 1.1 ± 0.2 fg/mL with DPV and 3.9 ± 0.5 fg/mL with EIS in phosphate-buffered saline (PBS) and 6.6 ± 3.1 fg/mL and 15.6 ± 3.1 fg/mL in human serum (HS), respectively. These results highlight the immunosensor's potential for improving early-stage cancer diagnosis and broader medical applications.
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Cellulose acetate membranes exhibit a potential to be applied in hemodialysis. However, their performance is limited by membrane fouling and a lack of antibacterial properties. In this research, copper oxide (I) nanoparticles were fabricated in situ into a cellulose acetate matrix in the presence of polyvinylpyrrolidone (pore-forming agent) and sulfobetaine (stabilising agent) to reduce the leakage of copper ions from nano-enhanced membranes. The influence of nanoparticles on the membrane structure and their antibacterial and antifouling properties were investigated. The results showed that incorporating Cu2O NPs imparted significant antibacterial properties against Staphylococcus aureus and fouling resistance under physiological conditions. The Cu2O NPs-modified membrane could pave the way for potential dialysis applications.
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Antibacterianos , Incrustaciones Biológicas , Celulosa , Cobre , Membranas Artificiales , Staphylococcus aureus , Celulosa/análogos & derivados , Celulosa/química , Celulosa/farmacología , Cobre/química , Antibacterianos/farmacología , Antibacterianos/química , Staphylococcus aureus/efectos de los fármacos , Incrustaciones Biológicas/prevención & control , Nanopartículas/química , Nanopartículas del Metal/química , Povidona/química , Povidona/análogos & derivadosRESUMEN
The evolving field of photocatalysis requires the development of new functional materials, particularly those suitable for large-scale commercial systems. One particularly promising approach is the creation of hybrid organic/inorganic materials. Despite being extensively studied, materials such as polydopamine (PDA) and titanium oxide continue to show significant promise for use in such applications. Nitrogen-doped titanium oxide and free-standing PDA films obtained at the air/water interface are particularly interesting. This study introduces a straightforward and reproducible approach for synthesizing a novel class of large-scale multilayer nanocomposites. The method involves the alternate layering of high-quality materials at the air/water interface combined with precise atomic layer deposition techniques, resulting in a gradient nitrogen doping of titanium oxide layers with exceptionally sharp oxide/polymer interfaces. The analysis confirmed the presence of nitrogen in the interstitial and substitutional sites of the TiO2 lattice while maintaining the 2D-like structure of the PDA films. These chemical and structural characteristics translate into a reduction of the band gap by over 0.63 eV and an increase in the photogenerated current by over 60% compared with pure amorphous TiO2. Furthermore, the nanocomposites demonstrate excellent stability during the 1 h continuous photocurrent generation test.
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In this study, we present a novel approach to enhancing the degradation of acetaminophen (ACT) using nanostructured hybrid nanofibers. The hybrid nanofibers were produced by employing both sol-gel and electrospinning methodologies, integrating precise quantities of silver (Ag) and boron nitride (BN) nanosheets into titanium oxide (TiO2) nanofibers and halloysite nanotubes (HNT). We extensively examined the morphology, structure, and optical properties of these materials by employing scanning electron microscopy, X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy in our analysis. In the case of the HNT-TiO2 composite, the introduction of Ag nanoparticles at concentrations of 0.5%, 1.5%, and 3% led to a significant improvement in photocatalytic activity. Under visible light exposure for 4 h, the photocatalytic activity increased from 63% (HNT-TiO2) to 78.92%, 91.21%, and 92.90%, respectively. This enhancement can be attributed to the role of Ag nanoparticles as co-catalysts, facilitating the separation of electrons and holes generated during the photocatalytic process. Furthermore, BN nanosheets served as co-catalysts, capitalizing on their distinct attributes, including exceptional thermal conductivity, chemical stability, and electrical insulation. The incorporation of BN nanosheets into the Ag (3%)/HNT-TiO2 composite at a concentration of 5% resulted in a remarkable increase in ACT degradation efficiency. The degradation efficiency improved from 59.47% to an impressive 99.29% within a 2-h irradiation period due to the presence of BN nanosheets. Toxicity and scavenging assays revealed that OHâ¢-, O2â¢-, and h+ were the major contributors to ACT degradation. Moreover, across five consecutive cycles, the Ag-BN/HNT-TiO2 composite exhibited consistent and stable performance, underscoring the significant contributions of Ag and BN in augmenting the photocatalytic capabilities of the composite. Overall, our findings suggest that this novel hybrid nanofiber composite holds great promise for practical applications in environmental remediation due to its improved photocatalytic activity and stability.
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In this study, we explore the potential of 1D ZnO-Au nanocomposites as innovative label-free photoluminescence (PL) immunosensors for rapidly detecting Listeria monocytogenes, a significant concern in food safety. We synthesized ZnO nanorods (ZnO_NR) and nanowires (ZnO_NW), followed by Au deposition to create ZnO_NR/Au and ZnO_NW/Au nanocomposites. Our analyses, including SEM, TEM, Raman spectroscopy, and photoluminescence (PL), revealed distinct structural and optical properties of these nanocomposites, especially noting the superior crystallinity and stability of ZnO_NR/Au. The biosensor performance was evaluated through PL sensitivity to Anti-Listeria antibodies, demonstrating that ZnO_NR with higher concentration of Au nanoparticles exhibited higher sensitivity and a lower limit of detection (LOD), attributed to a greater density of Listeria binding sites. The developed biosensor demonstrated a remarkable limit of detection (LOD) of 8.3 × 102 CFU/mL, rivaling or surpassing conventional culture-based methods and some molecular techniques. This research underscores the critical role of Au deposition duration in optimizing biosensor performance and presents a promising advancement in rapid and sensitive Listeria detection, with significant implications for enhancing food safety protocols.
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Técnicas Biosensibles , Listeria monocytogenes , Nanopartículas del Metal , Nanocompuestos , Óxido de Zinc , Óxido de Zinc/química , Técnicas Biosensibles/métodos , Oro/química , Nanopartículas del Metal/química , Inmunoensayo/métodos , Nanocompuestos/químicaRESUMEN
Current biosensors have limited application in clinical diagnostics as they lack the high order of specificity needed to detect low molecular analytes, especially in complex fluids (such as blood, urine, and saliva). In contrast, they are resistant to the suppression of non-specific binding. Hyperbolic metamaterials (HMMs) offer highly sought- after label-free detection and quantification techniques to circumvent sensitivity issues as low as 105 M concentration in angular sensitivity. This review discusses design strategies in detail and compares nuances in conventional plasmonic techniques to create susceptible miniaturized point-of-care devices. A substantial portion of the review is devoted to developing low optical loss reconfigurable HMM devices for active cancer bioassay platforms. A future perspective of HMM-based biosensors for cancer biomarker detection is provided.
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Técnicas Biosensibles , Neoplasias , Técnicas Biosensibles/métodos , Neoplasias/diagnósticoRESUMEN
In this study, we combined electrospinning of a large amount of halloysite (HNT, 95%) with nitriding to produce N-HNT-TiO2 composite nanofibers (N-H95T5 hereafter) to be used for acetaminophen (ACT) photodegradation. Investigation of the morphological and structural properties of the obtained materials did not highlight any significant difference in their morphological features and confirmed that nitrogen was evenly distributed in the samples. Photocatalytic tests under visible light showed that acetaminophen photodegraded faster in the presence of samples with nitrogen (N-H95T5) than without (H95T5 nanofibers). Moreover, the N-H95T5 nanocomposite photocatalytic activity did not change after repeated utilization (five cycles). The addition of scavengers during photocatalytic tests showed the key implication of OHâ¢-, O2â¢- and h+ radicals in acetaminophen degradation. These results indicated that N-H95T5 composite nanofibers could be considered a cheap multifunctional material for photodegradation and could open new prospects for preparing tunable photocatalysts.
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Novel multifunctional ZnO:Gd@ZIF-8 hybrid inorganic-organic nanocomposites with tunable luminescent-magnetic performance were successfully fabricated using wet chemistry synthesis routes. Physico-chemical characterization including crystal structure, phase compositions, morphology, surface properties, as well as photoluminescent and magnetic characteristics was performed using powder X-ray diffraction (XRD), FT-IR analysis, transmission and scanning electron microscopies (TEM/SEM), N2 adsorption/desorption, SQUID magnetometer, and photoluminescence spectroscopy. The biological studies of obtained materials, such as cytotoxicity profile and in vitro MRI imaging also investigated for potential use as contrast agents. Results showed that the doping with Gd3+ in a broad concentration range and the presence of ZIF-8 layer on ZnO affect the physico-chemical properties of the obtained composites. The obtained porous ZnO:Gd@ZIF-8 composites were highly crystalline with a large surface area. The XRD study indicated the formation of hexagonal wurtzite structure for ZnO and ZnO:Gd3+ (1-5 at.%). Luminescent studies showed, that ZnO is an ideal matrix for the incorporation of Gd3+ ions in a broad concentration range with efficient green luminescence. The PL intensity reached the maximum up to 5 at.% of Gd3+. The zeta potential values indicated the good stability of obtained nanoparticles. Proposed new materials with paramagnetic behavior and outstanding MR imaging capability could be used as potential contrast agents for magnetic resonance imaging.
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Nanocompuestos , Óxido de Zinc , Luminiscencia , Espectroscopía Infrarroja por Transformada de Fourier , Medios de Contraste , Imagen por Resonancia Magnética , Nanocompuestos/químicaRESUMEN
In this study, zinc oxide (ZnO) powders in two different morphologies, nanowire (NW) and nanoflower (NF), have been synthesized by the hydrothermal method. The eligibility of the pristine ZnO nanopowders as a photo-active material has been revealed by designing P-SC devices via the facile drop-casting method on both glass and plastic substrates in large-area applications. The impact of physical properties and especially defect structures on photo-supercapacitor (P-SC) performance have been explored. Although the dark Coulombic efficiency (CE%) of both NW and NF-based P-SC were very close to each other, the CE% of NW P-SC increased 3 times, while the CE% of NF P-SC increased 1.7 times under the UV-light. This is because the charge carriers produced under light excitation, extend the discharge time, and as confirmed by electron paramagnetic resonance, photoluminescence, and transmission electron microscopy analyses, the performance of P-SCs made from NF powders was relatively low compared to those produced from NW due to the high core defects in NF powders. The energy density of 78.1 mWh kg-1 obtained for NF-based P-SCs is very promising, and the capacitance retention value of almost 100% for 3000 cycles showed that the P-SCs produced from these materials were entirely stable. Compared to the literature, the P-SCs we propose in this study are essential for new generation energy storage systems, thanks to their ease of design, adaptability to mass production for large-area applications, and their ability to store more energy under illumination.
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Noninvasive, continuous glucose detection can provide some insights into daily fluctuations in blood glucose levels, which can help us balance diet, exercise, and medication. Since current commercially available glucose sensors can barely provide real-time glucose monitoring and usually imply different invasive sampling, there is an extraordinary need to develop new harmless methods for detecting glucose in non-invasive body fluids. Therefore, it is crucial to design (bio)sensors that can detect very low levels of glucose (down to tens of µM) normally found in sweat or tears. Apart from the selection of materials with high catalytic activity for glucose oxidation, it is also important to pay considerable attention to the electrode functionalization process, as it significantly contributes to the overall detection efficiency. In this study, the (ZnO tetrapods) ZnO TPs-based electrodes were functionalized with Nafion and chitosan polymers to compare their glucose detection efficiency. Cyclic voltammetry (CV) measurements have shown that chitosan-modified ZnO TPs require a lower applied potential for glucose oxidation, which may be due to the larger size of chitosan micelles (compared to Nafion micelles), and thus easier penetration of glucose through the chitosan membrane. However, despite this, both ZnO TPs modified with chitosan and Nafion membranes, provided quite similar glucose detection parameters (sensitivities, 7.5 µA mM-1 cm-1 and 19.2 µA mM-1 cm-1, and limits of detection, 24.4 µM and 22.2 µM, respectively). Our results show that both electrodes have a high potential for accurate real-time sweat/tears glucose detection.
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The aim of our work was the synthesis of ZnO nano- and microparticles and to study the effect of shapes and sizes on cytotoxicity towards normal and cancer cells and antibacterial activity toward two kinds of bacteria. We fabricated ZnO nano- and microparticles through facile chemical and physical routes. The crystal structure, morphology, textural properties, and photoluminescent properties were characterized by powder X-ray diffraction, electron microscopies, nitrogen adsorption/desorption measurements, and photoluminescence spectroscopy. The obtained ZnO structures were highly crystalline and monodispersed with intensive green emission. ZnO NPs and NRs showed the strongest antibacterial activity against Escherichia coli and Staphylococcus aureus compared to microparticles due to their high specific surface area. However, the ZnO HSs at higher concentrations also strongly inhibited bacterial growth. S. aureus strain was more sensitive to ZnO particles than the E. coli. ZnO NPs and NRs were more harmful to cancer cell lines than to normal ones at the same concentration.
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Nanopartículas del Metal , Óxido de Zinc , Antibacterianos/química , Antibacterianos/farmacología , Escherichia coli , Tecnología Química Verde/métodos , Nanopartículas del Metal/química , Pruebas de Sensibilidad Microbiana , Extractos Vegetales/farmacología , Espectroscopía Infrarroja por Transformada de Fourier , Staphylococcus aureus , Difracción de Rayos X , Óxido de Zinc/química , Óxido de Zinc/farmacologíaRESUMEN
Continuous painless glucose monitoring is the greatest desire of more than 422 million diabetics worldwide. Therefore, new non-invasive and convenient approaches to glucose monitoring are more in demand than other tests for microanalytical diagnostic tools. Besides, blood glucose detection can be replaced by continuous glucose monitoring of other human biological fluids (e.g. sweat) collected non-invasively. In this study, a skin-attachable and stretchable electrochemical enzymatic sensor based on ZnO tetrapods (TPs) and a new class of 2D materials - transition metal carbides, known as MXene, was developed and their electroanalytical behavior was tailored for continuous detection glucose in sweat. The high specific area of ZnO TPs and superior electrical conductivity of MXene (Ti3C2Tx) nanoflakes enabled to produce enzymatic electrochemical glucose biosensor with enhanced sensitivity in sweat sample (29 µA mM-1 cm-2), low limit of detection (LOD ≈ 17 µM), broad linear detection range (LDR = 0.05-0.7 mM) that satisfices glucose detection application in human sweat, and advanced mechanical stability (up to 30% stretching) of the template. The developed skin-attachable stretchable electrochemical electrodes allowed to monitor the level of glucose in sweat while sugar uptake and during physical activity. Continuous in vivo monitoring of glucose in sweat obtained during 60 min correlated well with data collected by a conventional amperometric blood glucometer in vitro mode. Our findings demonstrate the high potential of developed ZnO/MXene skin-attachable stretchable sensors for biomedical applications on a daily basis.
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Técnicas Biosensibles , Dispositivos Electrónicos Vestibles , Óxido de Zinc , Glucemia , Automonitorización de la Glucosa Sanguínea , Técnicas Electroquímicas , Electrodos , Glucosa , Humanos , SudorRESUMEN
The demand for fresh and clean water sources is increasing globally, and there is a need to develop novel routes to eliminate micropollutants and other harmful species from water. Photocatalysis is a promising alternative green technology that has shown great performance in the degradation of persistent pollutants. Titanium dioxide is the most used catalyst owing to its attractive physico-chemical properties, but this semiconductor presents limitations in the photocatalysis process due to the high band gap and the fast recombination of the photogenerated carriers. Herein, a novel photocatalyst has been developed, based on titanium dioxide nanofibers (TiO2 NFs) synthesized by electrospinning. The TiO2 NFs were coated by atomic layer deposition (ALD) to grow boron nitride (BN) and palladium (Pd) on their surface. The UV-Vis spectroscopy measurements confirmed the increase of the band gap and the extension of the spectral response to the visible range. The obtained TiO2/BN/Pd nanofibers were then tested for photocatalysis, and showed a drastic increase of acetaminophen (ACT) degradation (>90%), compared to only 20% degradation obtained with pure TiO2 after 4 h of visible light irradiation. The high photocatalytic activity was attributed to the good dispersion of Pd NPs on TiO2-BN nanofibers, leading to a higher transfer of photoexcited hole carriers and a decrease of photogenerated electron-charge recombination. To confirm its reusability, recycling tests on the hybrid photocatalyst TiO2/BN/Pd have been performed, showing a good stability over 5 cycles under UV and visible light. In addition, toxicity tests as well as quenching tests were carried out to check the toxicity of the byproducts formed and to determine active species responsible for the degradation. The results presented in this work demonstrate the potential of TiO2/BN/Pd nanomaterials, and open new prospects for the preparation of tunable photocatalysts.
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TitanioRESUMEN
In this study, we report a novel way to produce carbon-based conductive inks for electronic and sensor technology applications. Carbonized lignin, obtained from the waste products of the Eucalyptus globulus tree paper industry, was used to produce a stable conductive ink. To this end, liquid-phase compositions were tested with different amounts of carbonized lignin powder to obtain an ink with optimal conductivity and rheological properties for different possible uses. The combination that showed the best properties, both regarding electrochemical properties and green compatibility of the materials employed, was cyclohexanone/cellulose acetate/carbonized lignin 5% (w/w), which was used to produce screen-printed electrodes. The electrodes were characterized from a structural and electrochemical point of view, resulting in an electrochemically active area of 0.1813 cm2, compared to the electrochemically active area of 0.1420 cm2 obtained by employing geometrically similar petroleum-based screen-printed electrodes and, finally, their performance was demonstrated for the quantification of uric acid, with a limit of detection of 0.3 µM, and their biocompatibility was assessed by testing it with the laccase enzyme and achieving a limit of detection of 2.01 µM for catechol as the substrate. The results suggest that the developed ink could be of great use in both sensor and electronic industries, reducing the overall ecological impact of traditionally used petroleum-based inks.
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We developed free-standing nitrogen-doped carbon nanofiber (CNF) electrodes incorporating Co/CoOx nanoparticles (NPs) as a new cathode material for removing Acid Orange 7 (AO7; a dye for wool) from wastewater by the heterogeneous electro-Fenton reaction. We produced the free-standing N-doped CNF electrodes by electrospinning a polyacrylonitrile (PAN) and cobalt acetate solution followed by thermal carbonation of the cobalt acetate/PAN nanofibers under a nitrogen atmosphere. We then investigated electro-Fenton-based removal of AO7 from wastewater with the free-standing N-doped-CNFs-Co/CoOx electrodes, in the presence or not of Fe2+ ions as a co-catalyst. The electrochemical analysis showed the high stability of the prepared N-doped-CNF-Co/CoOx electrodes in electrochemical oxidation experiments with excellent degradation of AO7 (20 mM) at acidic to near neutral pH values (3 and 6). Electro-Fenton oxidation at 10 mA/cm2 direct current for 40 min using the N-doped-CNF-Co/CoOx electrodes loaded with 25 wt% of Co/CoOx NPs led to complete AO7 solution decolorization with total organic carbon (TOC) removal values of 92.4% at pH 3 and 93.3% at pH 6. The newly developed N-doped-CNF-Co/CoOx electrodes are an effective alternative technique for wastewater pre-treatment before the biological treatment.
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Zinc oxide (ZnO) nanostructures are widely used in optical sensors and biosensors. Functionalization of these nanostructures with polymers enables optical properties of ZnO to be tailored. Polydopamine (PDA) is a highly biocompatible polymer, which can be used as a versatile coating suitable for application in sensor and biosensor design. In this research, we have grown ZnO-based nanorods on the surface of ITO-modified glass-plated optically transparent electrodes (glass/ITO). Then the deposition of the PDA polymer layer on the surface of ZnO nanorods was performed from an aqueous PDA solution in such a way glass/ITO/ZnO-PDA structure was formed. The ZnO-PDA composite was characterized by SEM, TEM, and FTIR spectroscopy. Then glucose oxidase (GOx) was immobilized using crosslinking by glutaraldehyde on the surface of the ZnO-PDA composite, and glass/ITO/ZnO-PDA/GOx-based biosensing structure was designed. This structure was applied for the photo-electrochemical determination of glucose (Glc) in aqueous solutions. Photo-electrochemical determination of glucose by cyclic voltammetry and amperometry has been performed by glass/ITO/ZnO-PDA/GOx-based biosensor. Here reported modification/functionalization of ZnO nanorods with PDA enhances the photo-electrochemical performance of ZnO nanorods, which is well suited for the design of photo-electrochemical sensors and biosensors.
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Highly oriented, layered, and mechanically resilient films of polydopamine (PDA) have been synthesized from the air/water interface. The films show a unique layered structure, as shown by scanning and transmission electron studies (SEM/TEM) and X-ray diffraction analysis (XRD), which resemble that of 2D layered materials. The films exhibit a composition typical of PDA-based materials, as evidenced by X-ray photoelectron spectroscopy (XPS); moreover, the samples present the distinctive resonance modes of PDA-based nanomaterials in Raman and infrared spectroscopy (FTIR) experiments. The presence of highly ordinated 3-4 protomolecule stacking, taking place at the air/water interface, with a unique eumelanin-like supramolecular arrangement is presented. Moreover, the films show superior mechanical resilience with E = 13 ± 4 GPa and H = 0.21 ± 0.03 GPa, as revealed by nanoindentation experiments, making them highly resilient and easily transferable. Finally, the ordering induced by the interface opens many possibilities for further studies, including those regarding the supramolecular structure on PDA due to their similarity to 2D layered materials.