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- ItemIdentification of acetaldehyde based on plasmonic patterns of a gold nanostructure conjugated with chromophore and H2O2: a new platform for the rapid and low-cost analysis of carcinogenic agents by colorimetric affordable test strip (CATS)(ROYAL SOC CHEMISTRY, 2024-05-10) Farshchi, Fatemeh; Saadati, Arezoo; Bahavarnia, Farnaz; Hasanzadeh, Mohammad; Shadjou, NasrinAcetaldehyde, a prevalent carbonyl compound in fermented foods, poses challenges in various applications due to its reactivity. This study addresses the need for efficient acetaldehyde detection methods across biotechnological, environmental, pharmaceutical, and food sectors. Herein, we present a novel colorimetric/UV spectrophotometric approach utilizing gold nanoparticles (AuNPs), particularly gold nano-flowers (AuNFs), for sensitive acetaldehyde identification. The method exhibits a notable sensitivity, detecting acetaldehyde at concentrations as low as 0.1 mu M. The mechanism involves the interaction of acetaldehyde molecules with AuNFs, leading to a significant change in the absorbance spectrum, which serves as the basis for detection. Moreover, its applicability extends to human biofluids, notably urine samples. Integration with a cost-effective one-drop microfluidic colorimetric device (OD-mu PCD) enables the development of an affordable test strip (CATS). This semi-analytical device, employing a multichannel OD-mu PCD, facilitates real-time analysis of acetaldehyde in human samples. Our findings demonstrate the pioneering utilization of AuNPs for selective and sensitive acetaldehyde detection, promising advancements in environmental and occupational safety standards, and laying a foundation for enhanced detection and monitoring of related volatile organic compounds (VOCs).
- ItemSPEED: an integrated, smartphone-operated, handheld digital PCR Device for point-of-care testing(Springer Nature, 2024-05-20) Zhang, Haoqing; Liu, Xiaocheng; Wang, Xinlu; Yan, Zhiqiang; Xu, Ying; Gaňová, Martina; Řezníček, Tomáš; Korabečná, Marie; Neužil, PavelThis study elaborates on the design, fabrication, and data analysis details of SPEED, a recently proposed smartphone-based digital polymerase chain reaction (dPCR) device. The dPCR chips incorporate partition diameters ranging from 50 mu m to 5 mu m, and these partitions are organized into six distinct blocks to facilitate image processing. Due to the superior thermal conductivity of Si and its potential for mass production, the dPCR chips were fabricated on a Si substrate. A temperature control system based on a high-power density Peltier element and a preheating/cooling PCR protocol user interface shortening the thermal cycle time. The optical design employs four 470 nm light-emitting diodes as light sources, with filters and mirrors effectively managing the light emitted during PCR. An algorithm is utilized for image processing and illumination nonuniformity correction including conversion to a monochromatic format, partition identification, skew correction, and the generation of an image correction mask. We validated the device using a range of deoxyribonucleic acid targets, demonstrating its potential applicability across multiple fields. Therefore, we provide guidance and verification of the design and testing of the recently proposed SPEED device.
- ItemSmart bactericide based on reduced graphene oxide decorated with copper and zinc nanoparticles(Springer Nature, 2023-10-24) Bytešníková, Zuzana; Pečenka, Jakub; Tekielska, Dorota; Pekárková, Jana; Ridošková, Andrea; Bezdička, Petr; Kiss, Tomáš; Eichmeier, Aleš; Adam, Vojtěch; Lukas, RichteraGraphene oxide (GO) synthesised by modified Tour's method was decorated with copper and zinc nanoparticles (NPs) and simultaneously reduced by sodium borohydride to obtain a nanocomposite of reduced GO with copper and zinc NPs (rGO-Cu-Zn). The nanocomposite rGO-Cu-Zn was characterised by transmission electron microscopy (TEM), energy dispersive X-ray (EDX) spectroscopy, X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS). The rGO-Cu-Zn was tested against Xanthomonas euvesicatoria (X. euvesicatoria), which attacks tomatoes and causes bacterial spots (BSs), and compared with the commercial product Champion 50 WG. Total bacterial growth inhibition was observed for the 1% rGO-Cu-Zn, whereas Champion 50 WG at the same concentration inhibited but did not eradicate all the bacterial colonies. To evaluate the negative effect of the rGO-Cu-Zn on the molecular level, the expression of the genes associated with the action of abiotic and biotic stress factors was analysed. Gene expression in the plants treated with 10% rGO-Cu-Zn did not exhibit a noticeable increase.
- ItemOptimization of a silver-nanoprism conjugated with 3,3 ',5,5 '-tetramethylbenzidine towards easy-to-make colorimetric analysis of acetaldehyde: a new platform towards rapid analysis of carcinogenic agents and environmental technology(ROYAL SOC CHEMISTRY, 2023-02-14) Farshchi, Fatemeh; Saadati, Arezoo; Hasanzadeh, Mohammad; Liu, Yu-Qian; Seidi, FarzadAcetaldehyde acts as an important mediator in the metabolism of plants and animals; however, its abnormal level can cause problems in biological processes. Although acetaldehyde is found naturally in many organisms, exposure to high concentrations can have effects on the eyes, respiratory system, etc. Due to the importance of detecting acetaldehyde in environmental samples and biofluids, determination of its concentration is highly demanded. There are some reports showing exposure to high concentrations of acetaldehyde for a long time can increase the risk of cancer by reacting with DNA. In this work, we presented a novel colorimetric method for rapid and sensitive detection of acetaldehyde with high reproducibility using different AgNPs with various morphologies. The redox reaction between AgNPs, 3,3 ',5,5 '-tetramethylbenzidine (TMB) solution, and analytes endows a color change in 15 minutes that is detectable by the naked eye. UV spectrophotometry was further used for quantitative analysis. An iron mold with a hexagonal pattern and liquid paraffin were also used to prepare the paper-based microfluidic substrate, as a low cost, accessible, and rapid detection tool. Different types of AgNPs showed different lower limits of quantification (LLOQ). The AgNPs-Cit and AgNPrs could identify acetaldehyde with linear range of 10(-7) to 10 M and an LLOQ of 10(-7) M. The AgNWs showed the best color change activity with a linear range 10(-5) to 10 M and the lowest diagnostic limit is 10(-5) M. Finally, analysis of human biofluids as real samples were successfully performed using this system.
- ItemSilver Nanoparticle-Decorated Reduced Graphene Oxide Nanomaterials Exert Membrane Stress and Induce Immune Response to Inhibit the Early Phase of HIV-1 Infection(WILEY, 2023-02-01) Mukherjee, Soumajit; Bytešníková, Zuzana; Martin, Sophie; Švec, Pavel; Ridošková, Andrea; Pekárková, Jana; Seguin, Cendrine; Weickert, Jean-Luc; Mesaddeq, Nadia; Mély, Yves; Richtera, Lukáš; Anton, Halina; Adam, VojtěchGraphene-based 2D nanomaterials exhibit unique physicochemical, electric, and optical properties that facilitate applications in a wide range of fields including material science, electronics, and biotechnology. Recent studies have shown that graphene oxide (GO) and reduced graphene oxide (rGO) exhibit antimicrobial effects on bacteria and viruses. While the bactericidal activity of graphene-based nanomaterials is related to mechanical and oxidative damage to bacterial membranes, their antiviral activity has been less explored. Currently available experimental data are limited and suggest mechanical disruption of viral particles prior to infection. In this study, the antiviral properties of reduced GO-based nanocomposites decorated with Ag nanoparticles (rGO-Ag) are evidenced against human immunodeficiency virus-1 pseudovirus used as an enveloped virus model. By combining biochemical and original single virus imaging approaches, it is shown that rGO-Ag induces peroxidation of pseudoviral lipid membrane and that consequent alteration of membrane properties leads to a reduction in cell entry. In addition, rGO-Ag is found to be efficiently internalized in the host cell leading to the elevated expression of pro-inflammatory cytokines. Altogether, the presented results shed new light on the mechanisms of rGO-Ag antiviral properties and confirm the high potential of graphene derivatives as an antimicrobial material for biomedical applications.