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1.
Adv Colloid Interface Sci ; 333: 103304, 2024 Sep 26.
Article in English | MEDLINE | ID: mdl-39357211

ABSTRACT

The development of stimuli-responsive nanomaterials holds immense promise for enhancing the efficiency and effectiveness of water treatment processes. These smart materials exhibit a remarkable ability to respond to specific external stimuli, such as light, pH, or magnetic fields, and trigger the controlled release of encapsulated pollutants. By precisely regulating the release kinetics, these nanomaterials can effectively target and eliminate contaminants without compromising the integrity of the water system. This review article provides a comprehensive overview of the advancements in light-activated and pH-sensitive nanomaterials for controlled pollutant release in water treatment. It delves into the fundamental principles underlying these materials' stimuli-responsive behaviour, exploring the design strategies and applications in various water treatment scenarios. In particular, the article indicates how integrating stimuli-responsive nanomaterials into existing water treatment technologies can significantly enhance their performance, leading to more sustainable and cost-effective solutions. The synergy between these advanced materials and traditional treatment methods could pave the way for innovative approaches to water purification, offering enhanced selectivity and efficiency. Furthermore, the review highlights the critical challenges and future directions in this rapidly evolving field, emphasizing the need for further research and development to fully realize the potential of these materials in addressing the pressing challenges of water purification.

2.
Pharmaceuticals (Basel) ; 17(9)2024 Sep 03.
Article in English | MEDLINE | ID: mdl-39338328

ABSTRACT

In this review, we summarize the present state of a rapidly developing field of light-activated antimicrobial textiles and their underestimated potential and opportunities.

3.
Nanomicro Lett ; 16(1): 274, 2024 Aug 16.
Article in English | MEDLINE | ID: mdl-39147964

ABSTRACT

Early non-invasive diagnosis of coronary heart disease (CHD) is critical. However, it is challenging to achieve accurate CHD diagnosis via detecting breath. In this work, heterostructured complexes of black phosphorus (BP) and two-dimensional carbide and nitride (MXene) with high gas sensitivity and photo responsiveness were formulated using a self-assembly strategy. A light-activated virtual sensor array (LAVSA) based on BP/Ti3C2Tx was prepared under photomodulation and further assembled into an instant gas sensing platform (IGSP). In addition, a machine learning (ML) algorithm was introduced to help the IGSP detect and recognize the signals of breath samples to diagnose CHD. Due to the synergistic effect of BP and Ti3C2Tx as well as photo excitation, the synthesized heterostructured complexes exhibited higher performance than pristine Ti3C2Tx, with a response value 26% higher than that of pristine Ti3C2Tx. In addition, with the help of a pattern recognition algorithm, LAVSA successfully detected and identified 15 odor molecules affiliated with alcohols, ketones, aldehydes, esters, and acids. Meanwhile, with the assistance of ML, the IGSP achieved 69.2% accuracy in detecting the breath odor of 45 volunteers from healthy people and CHD patients. In conclusion, an immediate, low-cost, and accurate prototype was designed and fabricated for the noninvasive diagnosis of CHD, which provided a generalized solution for diagnosing other diseases and other more complex application scenarios.

4.
Talanta ; 279: 126667, 2024 Nov 01.
Article in English | MEDLINE | ID: mdl-39111217

ABSTRACT

Aptamers are good affinity receptors for bio-assays, while colorimetric method is suitable for point-of-care sensing via direct visualization. But previously aptamers often need complex re-engineering for colorimetric measurement at the cost of affinity and performance. Here isoquinoline alkaloids are found to own unique light-activated oxidative capacity, which can be specifically triggered by unmodified aptamers. This feature is universal for two alkaloids to efficiently oxidize four chromogenic substrates with obvious color changes. Based on a dye-displacement process, we have developed a novel light-activated aptamer system for the colorimetric assay of estradiol. It shows a good sensitivity with a detection limit of 326 nM, and this homogeneous assay is reliable to avoid artifacts in previous heterogeneous scheme. Besides, it is proven to be a universal design to assay other two targets. Significantly, they do not employ any aptamers re-engineering but only simply use their parental aptamers. Therefore, this light-activated oxidative capacity of isoquinoline alkaloid can serve as an ideal tool for colorimetric assay of various targets based on aptamer's specific recognition.


Subject(s)
Alkaloids , Aptamers, Nucleotide , Colorimetry , Isoquinolines , Light , Oxidation-Reduction , Aptamers, Nucleotide/chemistry , Colorimetry/methods , Alkaloids/analysis , Alkaloids/chemistry , Isoquinolines/chemistry , Isoquinolines/analysis , Limit of Detection
5.
Eur J Orthop Surg Traumatol ; 34(6): 3395-3400, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38967689

ABSTRACT

BACKGROUND: Post-operative non-compliance is a risk factor for fracture fixation failure and presents a challenge for revision surgery planning. We present a patient who underwent revision surgery for a proximal humerus fracture with lateral locked plating augmented with a UV light activated intramedullary implant. CASE: A 45-year-old woman with a history of alcoholism presented with a proximal humerus fracture. After undergoing open reduction internal fixation with a lateral locking plate, the patient suffered a fall secondary to delirium tremens. New radiographs demonstrated displacement of the fracture with failure of screws. Revision surgery consisting of removal of the initial construct as well as open reduction internal fixation via lateral locking plate, augmented with a UV-activated intramedullary cement implant, was performed. CONCLUSION: This is the first case report describing the use of a UV-activated intramedullary cement implant to augment the use of lateral locked plating for proximal humerus fractures. This case illustrates the successful management using UV-activated intramedullary cement to augment fixation, specifically in a patient with risk factors and post-operative non-compliance that predispose to fixation failure.


Subject(s)
Fracture Fixation, Intramedullary , Reoperation , Shoulder Fractures , Humans , Female , Middle Aged , Shoulder Fractures/surgery , Fracture Fixation, Intramedullary/adverse effects , Fracture Fixation, Intramedullary/instrumentation , Fracture Fixation, Intramedullary/methods , Bone Plates/adverse effects , Ultraviolet Rays/adverse effects , Bone Cements/adverse effects , Open Fracture Reduction/adverse effects , Open Fracture Reduction/methods , Accidental Falls , Alcoholism/complications
6.
Small Methods ; : e2400921, 2024 Jul 25.
Article in English | MEDLINE | ID: mdl-39049688

ABSTRACT

Low-energy visible-light-activated carbon dots (CDs)-based afterglow materials are difficult to realize due to the inherent aromatic carbon with high-energy absorption and the lack of effective regulation. Here, a new strategy for visible-light-activated CDs is proposed by combining dual-confinement and surface-ionization, which employs NaOH for additional confinement and surface ionization of CDs in a single boric acid (BA) matrix. The comparison experiments show that: i) shifting the excitation from UV-light to vis-light is realized by enhancing the low-energy surface states n→π* transition of the CDs by surface ionization of NaOH. ii) CDs are additionally protected by a more stable Na─O ionic bond after NaOH confinement, resulting in a brighter afterglow. iii) the energy gap (ΔEST) between the lowest singlet and triplet states is gradually shortened as increasing NaOH content, facilitating intersystem crossing, prolonging the lifetime of triplet excitons and efficiency. Further, vis-light-excited colorful afterglow powders are fabricated based on Förster Resonant Energy Transfer by combining the fluorescent dye 5-carboxytetramethylrhodamine. Finally, advanced white-light-activated time-resolved anti-counterfeiting and intelligent traffic flashing signs are realized. The work may shed new light on the design of low-energy-activated afterglow materials and broaden the application scenarios in the daily lives of human society.

7.
J Photochem Photobiol B ; 257: 112971, 2024 Aug.
Article in English | MEDLINE | ID: mdl-38955081

ABSTRACT

Bovine mastitis (BM) represents a significant challenge in the dairy industry. Limitations of conventional treatments have prompted the exploration of alternative approaches, such as photodynamic inactivation (PDI). In this study, we developed a PDI protocol to eliminate BM-associated pathogens using porphyrin-doped conjugated polymer nanoparticles (CPN). The PDI-CPN protocol was evaluated in four mastitis isolates of Staphylococcus and in a hyper-biofilm-forming reference strain. The results in planktonic cultures demonstrated that PDI-CPN exhibited a bactericidal profile upon relatively low light doses (∼9.6 J/cm2). Furthermore, following a seven-hour incubation period, no evidence of cellular reactivation was observed, indicating a highly efficient post-photodynamic inactivation effect. The successful elimination of bacterial suspensions encouraged us to test the PDI-CPN protocol on mature biofilms. Treatment using moderate light dose (∼64.8 J/cm2) reduced biofilm biomass and metabolic activity by up to 74% and 88%, respectively. The impact of PDI-CPN therapy on biofilms was investigated using scanning electron microscopy (SEM), which revealed nearly complete removal of the extracellular matrix and cocci. Moreover, ex vivo studies conducted on bovine udder skin demonstrated the efficacy of the therapy in eliminating bacteria from these scaffolds and its potential as a prophylactic method. Notably, the histological analysis of skin revealed no signs of cellular degeneration, suggesting that the protocol is safe and effective for BM treatment. Overall, this study demonstrates the potential of PDI-CPN in treating and preventing BM pathogens. It also provides insights into the effects of PDI-CPN on bacterial growth, metabolism, and survival over extended periods, aiding the development of effective control strategies and the optimization of future treatments.


Subject(s)
Biofilms , Light , Mastitis, Bovine , Nanoparticles , Polymers , Animals , Cattle , Nanoparticles/chemistry , Mastitis, Bovine/microbiology , Mastitis, Bovine/drug therapy , Biofilms/drug effects , Biofilms/radiation effects , Female , Polymers/chemistry , Polymers/pharmacology , Photosensitizing Agents/pharmacology , Photosensitizing Agents/chemistry , Porphyrins/chemistry , Porphyrins/pharmacology , Staphylococcus/drug effects , Staphylococcus/radiation effects , Anti-Bacterial Agents/pharmacology , Anti-Bacterial Agents/chemistry , Microscopy, Electron, Scanning , Photochemotherapy
8.
Biosensors (Basel) ; 14(3)2024 Mar 14.
Article in English | MEDLINE | ID: mdl-38534252

ABSTRACT

The rapid and accurate identification of parasites is crucial for prompt therapeutic intervention in parasitosis and effective epidemiological surveillance. For accurate and effective clinical diagnosis, it is imperative to develop a nucleic-acid-based diagnostic tool that combines the sensitivity and specificity of nucleic acid amplification tests (NAATs) with the speed, cost-effectiveness, and convenience of isothermal amplification methods. A new nucleic acid detection method, utilizing the clustered regularly interspaced short palindromic repeats (CRISPR)-associated (Cas) nuclease, holds promise in point-of-care testing (POCT). CRISPR/Cas12a is presently employed for the detection of Plasmodium falciparum, Toxoplasma gondii, Schistosoma haematobium, and other parasites in blood, urine, or feces. Compared to traditional assays, the CRISPR assay has demonstrated notable advantages, including comparable sensitivity and specificity, simple observation of reaction results, easy and stable transportation conditions, and low equipment dependence. However, a common issue arises as both amplification and cis-cleavage compete in one-pot assays, leading to an extended reaction time. The use of suboptimal crRNA, light-activated crRNA, and spatial separation can potentially weaken or entirely eliminate the competition between amplification and cis-cleavage. This could lead to enhanced sensitivity and reduced reaction times in one-pot assays. Nevertheless, higher costs and complex pre-test genome extraction have hindered the popularization of CRISPR/Cas12a in POCT.


Subject(s)
Body Fluids , Parasites , Animals , CRISPR-Cas Systems , RNA, Guide, CRISPR-Cas Systems , Biological Assay , Nucleic Acid Amplification Techniques
9.
Adv Mater ; 36(24): e2313731, 2024 Jun.
Article in English | MEDLINE | ID: mdl-38437162

ABSTRACT

Light-activated chemiresistors offer a powerful approach to achieving lower-temperature gas sensing with unprecedented sensitivities. However, an incomplete understanding of how photoexcited charge carriers enhance sensitivity obstructs the rational design of high-performance sensors, impeding the practical utilization under commonly accessible light sources instead of ultraviolet or higher-energy sources. Here, a rational approach is presented to modulate the electronic properties of the parent metal oxide phase, exemplified by this model system of Bi-doped In2O3 nanofibers decorated with Au nanoparticles (NPs) that exhibit superior NO2 sensing performance. Bi doping introduces mid-gap energy levels into In2O3, promoting photoactivation even under visible blue light. Additionally, green-absorbing plasmonic Au NPs facilitate electron transfer across the heterojunction, extending the photoactive region toward the green light. It is revealed that the direct involvement of photogenerated charge carriers in gas adsorption and desorption processes is pivotal for enhancing gas sensing performance. Owing to the synergistic interplay between the Bi dopants and the Au NPs, the Au-BixIn2-xO3 (x = 0.04) sensing layers attain impressive response values (Rg/Ra = 104 at 0.6 ppm NO2) under green light illumination and demonstrate practical viability through evaluation under simulated mixed-light conditions, all of which significantly outperforms previously reported visible light-activated NO2 sensors.

10.
Antimicrob Resist Infect Control ; 12(1): 116, 2023 10 24.
Article in English | MEDLINE | ID: mdl-37876020

ABSTRACT

BACKGROUND: Antimicrobial materials or surfaces are advertised as part of infection prevention bundles. However, the efficacy of such antimicrobial surfaces has not been sufficiently investigated in hospitals. In this study, the antimicrobial activity of examination gloves with light-activated antimicrobial properties against Gram-positive microorganisms was investigated modelling real live conditions. METHOD: In a standardized experimental set-up with dry and realistic contamination, the antimicrobial properties of gloves claiming light dependent antimicrobial activity against Gram-positive organisms were tested in comparison with conventional examination gloves. All gloves were contaminated through a standardized activity of the test persons for construction with contaminated building blocks. For contamination suspensions of Enterococcus faecium ATCC 6057, Acinetobacter baumannii (outbreak strain), methicillin resistant Staphylococcus aureus ATCC 43300 or E. faecium (VRE) patient isolate were dried on the surfaces. After the standardized activity, the gloves were held for 10 min in the light present in the room (bright conditions) and the grade of contamination was determined subsequently by quantitative culture. In one experimental series gloves were held in a dark box after contamination as a control (dark conditions). RESULTS: The light intensity in all experiments under bright conditions was significantly above the limit value specified by the manufacturer for the activation of antimicrobial properties (> 500 lx). The mean values for experiments with antimicrobial active and non-active gloves were 955 and 935 lx, respectively. As claimed by the manufacture, the gloves showed no sufficient efficacy against A. baumannii under bright conditions. Against Gram-positive microorganisms such as E. faecium, E. faecium (VRE) and methicillin resistant S. aureus the gloves showed only very low antimicrobial activity with a reduction factor < 1 log10 even after 10 min in bright conditions. Interestingly, comparable results for experiments with A. baumannii and E. faecium were shown under dark conditions. CONCLUSION: The lack of activity of the active principle against Gram-negative microorganisms could be confirmed. The reduction factors of > 4 log10 within 5 min for Gram-positive microorganisms claimed for the product using a standard test procedure (ASTM D7907) could not be confirmed in a realistic experimental test set-up even after 10 min of light exposure. The effectiveness against Gram-positive microorganisms should be further investigated under realistic (dry) conditions, including patient care. At this stage, the use of supposedly antimicrobial gloves should not be recommended, as the belief in their efficacy may encourage the misuse of gloves.


Subject(s)
Anti-Infective Agents , Enterococcus faecium , Methicillin-Resistant Staphylococcus aureus , Humans , Anti-Infective Agents/pharmacology
11.
Int J Mol Sci ; 24(18)2023 Sep 19.
Article in English | MEDLINE | ID: mdl-37762603

ABSTRACT

The present study investigates the relationship between the local structure, photocatalytic ability, and cathode performances in sodium-ion batteries (SIBs) and lithium-ion batteries (LIBs) using Ni-substituted goethite nanoparticles (NixFe1-xOOH NPs) with a range of 'x' values from 0 to 0.5. The structural characterization was performed applying various techniques, including X-ray diffractometry (XRD); thermogravimetry differential thermal analysis (TG-DTA); Fourier transform infrared spectroscopy (FT-IR); X-ray absorption spectroscopy (XANES/EXAFS), both measured at room temperature (RT); 57Fe Mössbauer spectroscopy recorded at RT and low temperatures (LT) from 20 K to 300 K; Brunauer-Emmett-Teller surface area measurement (BET), and diffuse reflectance spectroscopy (DRS). In addition, the electrical properties of NixFe1-xOOH NPs were evaluated by solid-state impedance spectroscopy (SS-IS). XRD showed the presence of goethite as the only crystalline phase in prepared samples with x ≤ 0.20, and goethite and α-Ni(OH)2 in the samples with x > 0.20. The sample with x = 0.10 (Ni10) showed the highest photo-Fenton ability with a first-order rate constant value (k) of 15.8 × 10-3 min-1. The 57Fe Mössbauer spectrum of Ni0, measured at RT, displayed a sextet corresponding to goethite, with an isomer shift (δ) of 0.36 mm s-1 and a hyperfine magnetic distribution (Bhf) of 32.95 T. Moreover, the DC conductivity decreased from 5.52 × 10-10 to 5.30 × 10-12 (Ω cm)-1 with 'x' increasing from 0.10 to 0.50. Ni20 showed the highest initial discharge capacity of 223 mAh g-1, attributed to its largest specific surface area of 174.0 m2 g-1. In conclusion, NixFe1-xOOH NPs can be effectively utilized as visible-light-activated catalysts and active cathode materials in secondary batteries.


Subject(s)
Minerals , Nanoparticles , Spectroscopy, Fourier Transform Infrared , Electrodes
12.
Biosensors (Basel) ; 13(9)2023 Aug 23.
Article in English | MEDLINE | ID: mdl-37754070

ABSTRACT

Functional nucleic acid (FNA) probes have been widely used in environmental monitoring, food analysis, clinical diagnosis, and biological imaging because of their easy synthesis, functional modification, flexible design, and stable properties. However, most FNA probes are designed based on one-photon (OP) in the ultraviolet or visible regions, and the effectiveness of these OP-based FNA probes may be hindered by certain factors, such as their potential for photodamage and limited light tissue penetration. Two-photon (TP) is characterized by the nonlinear absorption of two relatively low-energy photons of near-infrared (NIR) light with the resulting emission of high-energy ultraviolet or visible light. TP-based FNA probes have excellent properties, including lower tissue self-absorption and autofluorescence, reduced photodamage and photobleaching, and higher spatial resolution, making them more advantageous than the conventional OP-based FNA probes in biomedical sensing. In this review, we summarize the recent advances of TP-excited and -activated FNA probes and detail their applications in biomolecular detection. In addition, we also share our views on the highlights and limitations of TP-based FNA probes. The ultimate goal is to provide design approaches for the development of high-performance TP-based FNA probes, thereby promoting their biological applications.


Subject(s)
Diagnostic Imaging , Fluorescent Dyes , Nucleic Acid Probes , Photons , Light
13.
Environ Res ; 238(Pt 1): 117159, 2023 12 01.
Article in English | MEDLINE | ID: mdl-37722581

ABSTRACT

This study evaluated the photobiocidal performance of four widely distributed visible-light-activated (VLA) dyes against two bacteria (Staphylococcus epidermidis and Escherichia coli) and two bacteriophages (phages MS2 and phi 6): rose bengal (RB), crystal violet, methylene blue, and toluidine blue O (TBO). The photobiocidal performance of each dye depended on the relationship between the type of dye and microorganism. Gram-negative E. coli and the non-enveloped structure of phage MS2 showed more resistance to the photobiocidal reaction than Gram-positive S. epidermidis and the enveloped structure of phage phi 6. RB had the highest potential to yield reactive oxygen species. However, the photobiocidal performance of RB was dependent on the magnitude of the surface charge of the microorganisms; for example, anionic RB induced a negative surface charge and thus electrical repulsion. On the other hand, the photobiocidal performance of TBO was observed to be less affected by the microorganism type. The comparative results presented in our study have significant implications for selecting photodynamic antimicrobial chemotherapy (PACT) dyes suitable for specific situations and purposes. Furthermore, they contribute to the advancement of PACT-related technologies by enhancing their applicability and scalability.


Subject(s)
Anti-Infective Agents , Tolonium Chloride , Tolonium Chloride/chemistry , Tolonium Chloride/pharmacology , Methylene Blue/chemistry , Rose Bengal/chemistry , Gentian Violet , Photosensitizing Agents/chemistry , Escherichia coli , Coloring Agents
14.
Adv Mater ; 35(42): e2303267, 2023 Oct.
Article in English | MEDLINE | ID: mdl-37726261

ABSTRACT

Optogenetic modulation of brain neural activity that combines optical and electrical modes in a unitary neural system has recently gained robust momentum. Controlling illumination spatial coverage, designing light-activated modulators, and developing wireless light delivery and data transmission are crucial for maximizing the use of optical neuromodulation. To this end, biocompatible electrodes with enhanced optoelectrical performance, device integration for multiplexed addressing, wireless transmission, and multimodal operation in soft systems have been developed. This review provides an outlook for uniformly illuminating large brain areas while spatiotemporally imaging the neural responses upon optoelectrical stimulation with little artifacts. Representative concepts and important breakthroughs, such as head-mounted illumination, multiple implanted optical fibers, and micro-light-delivery devices, are discussed. Examples of techniques that incorporate electrophysiological monitoring and optoelectrical stimulation are presented. Challenges and perspectives are posed for further research efforts toward high-density optoelectrical neural interface modulation, with the potential for nonpharmacological neurological disease treatments and wireless optoelectrical stimulation.


Subject(s)
Brain , Nervous System Physiological Phenomena , Brain/physiology , Prostheses and Implants , Electrodes , Electricity
15.
Turk J Chem ; 47(2): 504-513, 2023.
Article in English | MEDLINE | ID: mdl-37528923

ABSTRACT

Photothermal materials and coatings which can create temperature elevations under light irradiation can be utilized in various applications requiring remote heating. Here, multiwalled carbon nanotubes (MWNT) were incorporated into waterborne polyurethane (PU) to obtain photothermal coatings with light-to-heat conversion properties. Resulting PU-MWNT coatings were demonstrated to heat up to 80 °C under sunlight irradiation at 2 sunlight density for 18 min. Pseudomonas aeruginosa (P. aeruginosa) cells attached to surfaces coated with PU-MWNT nanocomposites were killed upon near infrared (NIR) light irradiation at 808 nm for 15 min, whereas the same cells attached to control neat PU-coated surfaces remained alive under the same irradiation conditions. Furthermore, a scratch of 1 cm width on the PU-MWNT coating was shown to be healed under 12 min of sunlight irradiation. The PU-MWNT nanocomposites have strong potential as photothermal coatings, which can be remotely heated with NIR light activation.

16.
Methods Mol Biol ; 2676: 21-40, 2023.
Article in English | MEDLINE | ID: mdl-37277622

ABSTRACT

Genetically encoded site-specifically incorporated noncanonical amino acids (ncAAs) have been used to modulate properties of several proteins. Here, we describe a procedure for engineering photoactive antibody fragments that bind to their target antigen only after irradiation with 365 nm light. The procedure starts with identification of tyrosine residues in antibody fragments that are important for antibody-antigen binding and thus targets for replacement with photocaged tyrosine (pcY). This is followed by cloning of plasmids and expression of pcY-containing antibody fragments in E. coli. Finally, we describe a cost-effective and biologically-relevant method for measuring the binding affinity of photoactive antibody fragments to antigens expressed on the surface of live cancer cells.


Subject(s)
Escherichia coli , Immunoglobulin Fragments , Immunoglobulin Fragments/metabolism , Escherichia coli/genetics , Escherichia coli/metabolism , Amino Acids/chemistry , Tyrosine/metabolism , Proteins/chemistry , Antigens/metabolism
17.
BBA Adv ; 3: 100085, 2023.
Article in English | MEDLINE | ID: mdl-37378355

ABSTRACT

The present Review is an attempt by projecting the basic knowledge on photochemical proton transfer to achieve consistent understanding of proton motions in biocatalysis, photobiocatalysis, operation of selective proton channels and systems of photosynthesis and cellular respiration. The basic mechanisms of proton transfer are in active research in the electronic excited states of organic molecules. This allows observing the reactions directly in real time, providing their dynamic and thermodynamic description and coupling with structural and energetic variables. These achievements lay the background for understanding the proton transfers in biochemical reactions, where such ultrafast events are not only 'optically silent' but are hidden under much slower rate-limiting steps, such as protein conformational changes, substrate binding and product release. The mechanistic description of biocatalytic and transmembrane proton transport is shown as a multi-step proton migration that is available for modeling in photochemical reactions. For explaining the formation of transmembrane proton gradients, a simple 'proton lift' concept is presented that may be the basis of further research and analysis.

18.
Chempluschem ; 88(4): e202300125, 2023 04.
Article in English | MEDLINE | ID: mdl-36970973

ABSTRACT

Photo-oxidase nanozymes are emerging enzyme-mimicking materials that produce reactive oxygen species (ROS) upon light illumination and subsequently catalyze the oxidation of the substrate. Carbon dots are promising photo-oxidase nanozymes due to their biocompatibility and straightforward synthesis. Carbon dot-based photo-oxidase nanozymes become active for ROS generation under UV or blue light illumination. In this work, sulfur and nitrogen doped carbon dots (S,N-CDs) were synthesized by solvent-free, microwave assisted technique. We demonstrated that sulfur, nitrogen doping of carbon dots (band gap of 2.11 eV) has enabled photo-oxidation of 3,3,5,5'-tetramethylbenzidine (TMB) with extended visible light (up to 525 nm) excitation at pH 4. The photo-oxidase activities by S,N-CDs produce Michaelis-Menten constant (Km ) of 1.18 mM and the maximum initial velocity (Vmax ) as 4.66×10-8  Ms-1 , under 525 nm illumination. Furthermore, visible light illumination can also induce bactericidal activities with growth inhibition of Escherichia coli (E. coli). These results demonstrate that S,N-CDs can increase intracellular ROS in the presence of LED light illumination.


Subject(s)
Anti-Infective Agents , Oxidoreductases , Oxidoreductases/chemistry , Reactive Oxygen Species , Escherichia coli , Light , Carbon/chemistry , Nitrogen/chemistry , Sulfur/chemistry
19.
Talanta ; 255: 124236, 2023 Apr 01.
Article in English | MEDLINE | ID: mdl-36587430

ABSTRACT

Acid phosphatase (ACP) is a key marker in the diagnosis of many diseases. However, exploiting a simple and sensitive sensor for the real-time quantitative analysis of ACP is still challenging. Herein, we attempted to develop a sensitive colorimetric sensing strategy for the detection of ACP based on light-activated oxidase mimic property of carbon dots (CDs). The synthesized CDs were proved to be capable of intrinsic light-activated oxidase mimic activity, which could generate reactive oxygen species to oxidize chromogenic substrate under ultraviolet light stimulation. Interestingly, this light-activated oxidase mimic behavior would be effectively suppressed by the antioxidant ascorbic acid (AA), a product from the hydrolysis of 2-phospho-L-ascorbic acid trisodium (AAP) mediated by ACP. Based on the above property, a facile and sensitive colorimetric sensing method for ACP was developed. Under the optimal conditions, the linear range for ACP 0.1-5.5 U/L, and the detection limit was 0.056 U/L. Compared with conventional nanozyme based ACP assay systems, the catalytic activity of light-activated nanozyme could be conveniently regulated by switching the light on and off, which made it easier to precisely control the extent of the reaction and ensured the accuracy of the assay. In addition, the proposed sensing system would be readout directly by the naked eye or smartphone-based RGB analysis system, and have been successfully applied to analyze diluted in diluted fetal bovine serum and urine samples spiked with ACP. All these results indicated that this approach holds good promise for future applications in clinical analysis and point-of-care (POC) biosensor platforms.


Subject(s)
Acid Phosphatase , Oxidoreductases , Oxidoreductases/chemistry , Acid Phosphatase/analysis , Hydrolysis , Ascorbic Acid/chemistry , Antioxidants , Colorimetry/methods , Carbon/chemistry , Limit of Detection
20.
Materials (Basel) ; 17(1)2023 Dec 21.
Article in English | MEDLINE | ID: mdl-38203891

ABSTRACT

Mineralized connective tissues represent the hardest materials of human tissues, and polymer based composite materials are widely used to restore damaged tissues. In particular, light activated resins and composites are generally considered as the most popular choice in the restorative dental practice. The first purpose of this study is to investigate novel highly reinforced light activated particulate dental composites. An innovative additive manufacturing technique, based on the extrusion of particle reinforced photo-polymers, has been recently developed for processing composites with a filler fraction (w/w) only up to 10%. The second purpose of this study is to explore the feasibility of 3D printing highly reinforced composites. A variety of composites based on 2,2-bis(acryloyloxymethyl)butyl acrylate and trimethylolpropane triacrylate reinforced with silica, titanium dioxide, and zirconia nanoparticles were designed and investigated through compression tests. The composite showing the highest mechanical properties was processed through the 3D bioplotter AK12 equipped with the Enfis Uno Air LED Engine. The composite showing the highest stiffness and strength was successfully processed through 3D printing, and a four-layer composite scaffold was realized. Mechanical properties of particulate composites can be tailored by modifying the type and amount of the filler fraction. It is possible to process highly reinforced photopolymerizable composite materials using additive manufacturing technologies consisting of 3D fiber deposition through extrusion in conjunction with photo-polymerization.

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