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Surface Enhanced Raman Spectroscopy (SERS) technique is an effective analytical technique in which fingerprint information about analytes can be obtained, can provide detection limit performance at the single molecule level, and analyzes are performed in a single step without any intermediate steps. SERS technique offers additional benefits rather than other analytical techniques including high selectivity, ultrasensitive detection, uncomplicated protocols, in situ sampling, on-set capability and cost-effectiveness. As a result of the combination of developments in materials and nanotechnology science with the SERS analysis technique, this technique strengthens its use advantage day by day. The most important factor that limited the use of this technique was the fact that the solution containing the desired analyte(s) was dropped onto the SERS substrate and the same substrate could not be reused in subsequent analyses. To solve this problem, scientists have focused on developing reusable SERS substrates in recent years. In these studies, scientists basically used three SERS substrate cleaning applications (1) washing the SERS substrate with a suitable solvent that can elute the analyte from SERS surface after analysis, (2) cleaning the SERS substrate with catalytic degradation of analytes after analysis by modifying them with catalytic active materials and (3) Applying plasma cleaning procedure to SERS substrate after analysis and (4) applying adsorption and desorption procedure prior to SERS analysis. Herein, the aim of this review article is to evaluate the reusable SERS substrates-based methods based on their level of development and their potential to recycle. This review offers a coherent discussion on a wide range of sensing schemes employed in fabricating the SERS substrates. We utilized a critical approach in which elaborative examples were selected to highlight key shortcomings of various experimental configurations. In the same vein, there is a discussion of the advantages and limitations concerning the key instrumental advances and the expansion of the recent methods developed in this area.
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INTRODUCTION: Abacavir is among the first-line initial antiretroviral regimens for most patients living with HIV/AIDS (PLWHA). Although well tolerated, it is associated with hypersensitivity reaction (HSR), which is treatment-limiting and potentially life-threatening. HSR was shown to be associated with the class I MHC allele, HLA-B*57:01. In this study, we aimed to evaluate the prevalence of HLA-B*57:01 in PLWHA in Istanbul, Türkiye. MATERIAL AND METHODS: Five HIV treatment centers in Istanbul included all sequential treatment-- naïve, ≥ 18 years adult PLWHA, between December 2017- December 2021. Demographic, clinical, and laboratory data were collected at baseline and during treatment. HLA-B* 57:01 genotyping was determined with PCR-SSP. RESULTS: Eight hundred sixty-seven PLWHA were included (male:91%, mean age 39.6±11.1 years). 1.6% of patients were found to be HLA-B*57:01 positive. Among HLA-B*57:01 positive patients, 4 were initially given abacavir-containing treatment; they were switched to non-abacavir treatment upon the allele found to be positive. CONCLUSION: Although previous studies reported the HLA-B*57:01 prevalence of PLWHA in Türkiye as 3-3.6%, we have found the prevalence to be 1.6%. The current study includes higher numbers of patients than the previous studies. Furthermore, patients from all over the country apply to the centers in Istanbul; compared to the other studies, which involve patients limited to the relevant regions, it can be assumed that the number in our cohort is more representative of the country. In conclusion, the prevalence of the HLA-B*57:01 allele in PLWHA in this study is relatively low. With evident benefit in preventing abacavir HSR, HLA-B*57:01 should be screened in planning antiretroviral therapy.
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PURPOSE: The purpose of this study was to analyze the effect of scanning modes on the accuracy of the Trios for full-arch digital implant impressions. MATERIALS AND METHODS: The trueness and precision of the intraoral scanning mode (IOSM) and the intraoral edentulous scanning mode (IOEM) of the Trios were evaluated in three edentulous models, each featuring 4, 6, and 8 implant analogues. Reference scanning data were obtained by scanning each model with a desktop scanner. Each model was scanned 10 times using the IOSM and IOEM modes of the Trios to establish the test groups. The scan bodies in the test and reference scans were isolated and exported in the reverse engineering program. The scan bodies in each group were superimposed with the corresponding reference scan (trueness) or with each other (precision). The overall 3D deviation between the aligned scan bodies was computed by the root-meansquare (RMS) values. RESULTS: As a result of the trueness and precision evaluation, no significant difference was found between scanning modes in any of the models. When comparing models, the 8-implant model showed significantly lower trueness than the 4-implant model. However, it also exhibited significantly higher precision when compared to both the 4-implant and 6-implant models. There were no significant differences in other pairwise comparisons between the models. CONCLUSION: Trueness and precision values were similar between the IOSM and IOEM groups across all the models. An increase in the number of implants in complete edentulous arches may have a negative impact on digital impression accuracy.
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The optimal scan pattern for full-arch digital implant impressions remains to be determined. This study aimed to analyze the effects of different scan patterns on the trueness of intraoral scanners for full-arch digital implant impressions. A maxillary plaster model with 4 implant analogs was employed as the master model. Scan bodies were attached to the master model and scanned with a laboratory scanner to obtain reference data. Test scans were obtained using 3 different scan patterns with Cerec Primescan and Trios 3. Each test datum was superimposed onto the reference data. The trueness was assessed by determining the 3D distance and angular deviations between the test and reference data. Significant differences in 3D distance deviation were detected among the scan patterns for both scanners. Significant differences in angle deviation were detected among the scan patterns for the Cerec Primescan, whereas it was not substantial for the Trios 3. Cerec Primescan exhibited superior trueness across all scan patterns compared with Trios 3. The zigzag pattern resulted in more accurate scans for the Cerec Primescan, whereas both the zigzag and occlusal-palatal-buccal patterns showed higher accuracy for the Trios 3.
Subject(s)
Computer-Aided Design , Dental Impression Technique , Dental Impression Technique/instrumentation , Humans , Imaging, Three-Dimensional , Models, Dental , Dental Implants , Maxilla/diagnostic imagingABSTRACT
AIM: To investigate the autoimmune and genetic relationship between primary hypophysitis (PH) and celiac disease (CD). METHODS: The study was retrospective and patients with PH followed in our clinic between 2007 and 2022 were evaluated. Clinical, endocrinologic, pathologic, and radiologic findings and treatment modalities were assessed. Patients diagnosed with CD in the Gastroenterology outpatient clinic in 2020-2022 were included in the study as a control group. Information such as sociodemographic data, year of diagnosis, human leukocyte antigen (HLA) DQ2/8 information, CD-specific antibody levels, pathologic results of duodenal biopsy, treatment received, follow-up status, additional diseases, hormone use, and surgical history was obtained from patient records at PH.In patients diagnosed with PH, a duodenal biopsy was obtained, and the tissue was examined for CD by experienced pathologists. Anti-pituitary antibody (APA) and anti-arginine-vasopressin (AAVP) antibody levels of individuals with PH and CD were measured. RESULTS: The study included 19 patients with lymphocytic hypophysitis, 30 celiac patients, and 30 healthy controls. When patients diagnosed with lymphocytic hypophysitis were examined by duodenal biopsy, no evidence of CD was found in the pathologic findings. The detection rate of HLA-DQ2/8 was 80% in celiac patients and 42% in PH (p=0.044). (APA and AAVP antibodies associated with PH were tested in two separate groups of patients and in the control group. APA and anti-arginine vasopressin (AAVP) levels in PH, CD and healthy controls, respectively M [IQR]: 542 [178-607];164 [125-243]; 82 [74-107] ng/dL (p=0.001), 174 [52-218]; 60 [47-82]; 59 [48-76] ng/dL (p=0.008) were detected. The presence of an HLA-DQ2/8 haplotype correlates with posterior hypophysitis and panhypophysitis (r=0.598, p=0.04 and r=0.657, p=0.02, respectively). CONCLUSION: Although patients with PH were found to have significant levels of HLA-DQ2/8, no CD was found in the tissue. Higher levels of pituitary antibodies were detected in celiac patients compared with healthy controls, but no hypophysitis clinic was observed at follow-up. Although these findings suggest that the two diseases may share a common genetic and autoimmune basis, the development of the disease may be partially explained by exposure to environmental factors.
Subject(s)
Autoimmune Hypophysitis , Celiac Disease , Humans , Celiac Disease/complications , Celiac Disease/diagnosis , Retrospective Studies , Autoimmune Hypophysitis/complications , Haplotypes , Vasopressins/geneticsABSTRACT
In this investigation, two new thermophilic bacteria were isolated. The new isolates were characterized by 16S rRNA, biochemical, morphological, and physiological analyzes and the isolates were identified as Geobacillus stearothermophilus strain Gecek20 and thermophilic Anoxybacillus flavithermus strain Gecek19. Various biological activities of extracellular Ag-NPs synthesized from thermophilic G. stearothermophilus strain Gecek20 and thermophilic A. flavithermus strain Gecek19 were evaluated. The produced NPs were analyzed by SEM, SEM-EDX, and XRD analyses. The antioxidant abilities of new synthesized Ag-NPs from thermophilic G. stearothermophilus strain Gecek20 (T1-Ag-NPs) and new synthesized Ag-NPs from thermophilic A. flavithermus strain Gecek19 (T2-Ag-NPs) were studied by DPPH inhibition and metal chelating ability. The highest DPPH and metal chelating abilities of T1-Ag-NPs and T2-Ag-NPs at 200 mg/L concentration were 93.17 and 90.85%, and 75.80 and 83.64%, respectively. The extracellular green synthesized T1-Ag-NPs and T2-AgN-Ps showed DNA nuclease activity at all tested concentrations. Moreover, both new synthesized Ag-NPs had antimicrobial activity against the strains studied, especially on Gram positive bacteria. T1-Ag-NPs and T2-AgNPs also showed powerful Escherichia coli growth inhibition. The highest biofilm inhibition percentages of T1-Ag-NPs and T2-Ag-NPs against Pseudomonas aeruginosa and Staphylococcus aureus were 100.0%, respectively, at 500 mg/L.
Subject(s)
Anoxybacillus , Geobacillus stearothermophilus , Metal Nanoparticles , RNA, Ribosomal, 16S , Silver/pharmacology , Escherichia coliABSTRACT
Natural killer (NK) cells are immune cells that have attracted significant attention due to their cytotoxic properties. They are believed to be highly effective in cancer therapy. In this study, anti-KIR2DL4 (Killer cell Immunoglobulin like Receptor, 2 Ig Domains and Long cytoplasmic tail 4) was used to stimulate the NK-92 activator receptor to increase their cytotoxicity on breast cancer cell lines. Unstimulated and stimulated NK-92 cells (sNK-92) were cocultured with breast cancer (MCF-7 and SK-BR-3) and normal breast (MCF-12A) cell lines at 1:1, 1:5, and 1:10 (Target:Effector) ratios. The most effective cell cytotoxicity ratio (1:10) was used in the immunostaining and western blot assays to evaluate apoptosis pathway proteins. The sNK-92 cells showed higher cytotoxic activity on breast cancer cells than NK-92 cells. sNK-92 cells had a selective significant cytotoxicity effect on MCF-7 and SK-BR-3 cells but not MCF-12A cells. While sNK-92 cells were effective at all cell concentrations, they were most effective at a 1:10 ratio. Immunostaining and western blots showed significantly higher BAX, caspase 3, and caspase 9 protein levels in all breast cancer cell groups cocultured with sNK-92 than with NK-92 cells. NK-92 cells stimulated with KIR2DL4 showed elevated cytotoxic activity. The cytotoxic activity of sNK-92 cells on breast cancer cells is via apoptosis pathways. However, their effect on normal breast cells is limited. While the obtained data contains only basic information, additional clinical studies are needed to provide a basis for a new treatment model.
Subject(s)
Antineoplastic Agents , Breast Neoplasms , Humans , Female , Breast Neoplasms/metabolism , Killer Cells, Natural , Cytotoxicity, Immunologic , Antineoplastic Agents/pharmacology , MCF-7 Cells , Receptors, KIR2DL4/metabolismABSTRACT
BACKGROUND: The analysis of drug active molecules and residues in the treatment of cancer is important for the sustainability of human life and therapeutic effects. For this purpose, a new magnetic sorbent was developed to use in solid phase extraction prior to conventional high-performance liquid chromatography (HPLC) analysis of Paclitaxel (PAC) and Gemcitabine (GEM) molecules. METHODS: In this study, a separation and pre-concentration approach based on magnetic solid phase extraction (MSPE) was proposed for PAC and GEM by means of using a newly synthesized magnetic sorbent. After the MSPE procedure, an HPLC system with a diode array detector (DAD) was used to analyze trace amounts of PAC and GEM anticarcinogenic drugs in urine samples. Surface modification of magnetic Fe3O4 nanoparticles was carried out by diaminobenzidinetetrachloro hydrate (DABTC) for the first time and a useful sorbent was obtained for MSPE experiments. RESULTS: In the proposed method, PAC and GEM molecules were retained on the c in the presence of a pH 5.0 medium and desorbed to 300 µL of acetonitrile: methyl alcohol (1:1) eluent phase before HPLC-DAD analysis. Under the optimized conditions, the limit of detection (LOD) values for PAC and GEM were 1.38 and 1.44 ng mL-1 while the enhancement factor for PAC and GEM were 139.5 and 145.3, respectively. The relative standard deviations (RSD %) for PAC and GEM were below 3.50% in inter-day repeated experiments by means of model solutions containing 100 ng mL-1 drug active ingredients. CONCLUSIONS: Synthesis and characterization of DABTC-Fe3O4 nanoparticles were performed using suitable methodologies. Optimization of MSPE was done step by step. And finally, the developed method was successfully applied to urine samples with quantitative recoveries in the range of 99.0% and 105.0%.
Subject(s)
Antineoplastic Agents , Magnetite Nanoparticles , Humans , Magnetite Nanoparticles/chemistry , Adsorption , Solid Phase Extraction/methods , Magnetic Phenomena , Chromatography, High Pressure Liquid/methods , Limit of DetectionABSTRACT
Acrylamide is a compound that occurs with high temperature during food processing and causes oxidative damage. Recently, the importance of antioxidative components is increasing to prevent oxidative damage. Lactoferrin is an antioxidant protein mainly found in milk. Therefore, the aim of this study is to determine the dose-dependent protective effects of lactoferrin on oxidative damage caused by acrylamide. In this study, HepG2 cell lines were treated with lactoferrin doses (0, 25, 50, 100µM) and half maximal inhibitory concentration of acrylamide. After 24 hours malondialdehyde, superoxide dismutase, catalase and glutathione reductase levels were measured. Acrylamide significantly increased malondialdehyde levels in HepG2 cells compared to the control group; however, catalase, superoxide dismutase and glutathione reductace significantly reduced. On the other hand, added lactoferrin doses (50-100µM) significantly reduced lipid peroxidation levels. Besides, it was found that glutathione reductase, catalase and superoxide dismutase levels significantly increased. As a result, the protective effect of lactoferrin against the oxidative damage caused by acrylamide in HepG2 cells was determined. This effect is thought to be due to the antioxidant capacity of lactoferrin. In this context, it is recommended that more studies are carried out on the mechanism of action of lactoferrin on oxidative stress caused by acrylamide.
Subject(s)
Acrylamide , Oxidative Stress , Acrylamide/toxicity , Glutathione ReductaseABSTRACT
Environmental pollution and energy storage are among the most pivotal challenges of today's world. The development of multifunctional materials is required to address these challenges. Our study presents the rational design and synthesis of a hybrid material (ZIF-8@BiPO4) with dual functionality: an outstanding supercapacitor electrode and an excellent photocatalyst. The ZIF-8@BiPO4 hybrid structure was obtained by conjoining zinc ions and 2-methylimidazole ligands toward BiPO4 by a one-pot stirring route at room temperature. The ZIF-8@BiPO4 resulted in considerably higher specific capacitance (Cs) (489 F g-1 at a scan rate of 5 mV s-1; 497 F g-1 at a current density of 1 A g-1) than that of pure BiPO4 (358; 443 F g-1) and ZIF-8 (185; 178 F g-1) under the same conditions in a three-electrode cell using the 2 M KOH aqueous electrolyte. Afterward, an asymmetric supercapacitor (ASC) device was fabricated with BiPO4 as the anode and ZIF-8@BiPO4 as the cathodes, acquiring an outstanding Cs of 255 F g-1 at a current density of 0.5 A g-1 with significant cycling stability (81% over 10,000 cycles). Moreover, the ASC has an energy density of 17.5 Wh kg-1and a power density of 13,695 W kg-1, which can be considered to be at the borderline between batteries and supercapacitors. The photocatalytic activity of ZIF-8@BiPO4 was further studied using a methylene blue (MB) dye and sildenafil citrate (SC) drug-active molecules. The degradation of MB was approximately 78% through the photocatalytic reduction after 180 min of UV irradiation. The outstanding characteristics together with the ecofriendly and low-cost preparation make ZIF-8@BiPO4 appealing for a broad range of applications.
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In recent times, access to clean water has become increasingly difficult and one of the most important problems for the sustainability of life due to environmental pollution. Based on this thought, in this study, a multifunctional hydrogel nanocomposite (nanoclay@TiO2@PNVP) containing linear poly(N-vinyl pyrrolidone) (PNVP), nanoclay, and TiO2 nanoparticles was synthesized and used as an adsorbent and photocatalyst for the adsorption-based and photocatalytic degradation-based removal of organic and pharmaceutical pollutants such as methylene blue (MB) and sildenafil citrate (SLD). The modification of the hydrogel with TiO2 nanoparticles and nanoclay aimed to increase the adsorption capacity of the PNVP hydrogel as well as to gain photocatalytic properties for the effective removal of organic contaminants. This hybrid material, which can be cleaned in two different ways, can be reused and recycled at least 10 times. Characterization studies were carried out using Fourier transform infrared spectroscopy, scanning electron microscopy, Raman spectroscopy, thermogravimetric analysis, differential thermogravimetry, and viscosimetry techniques. Optimization studies for the adsorption-based removal of organic contaminants were carried out on MB and SLD as model organic compounds. The optimum parameters for MB were found at pH 10 of the sample solution when 50 mg of the nanoclay@TiO2@PNVP hydrogel nanocomposite was used for 420 min of contact time. It was observed that 99% of the MB was photocatalytically degraded within 150 min at pH 10. Our material had multifunctional applicability properties, showing high adsorption and photocatalytic performances over 99% for at least 10 times of use. For the removal of organic and pharmaceutical contaminants from wastewater, the synthesized material can be used in two treatment processes separately or in combination in one step, providing an important advantage for its usability in environmental applications.
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In this period when environmental pollution has become uncontrollable, the removal of drug active substances reaching the environment and the analysis of drug active substances in different matrix environments are important for both living life and a sustainable environment. Therefore, the production of multifunctional materials that can be used in these two different processes has gained importance in the literature. Based on this thought, in this study, a g-C3N4@TiO2@Fe3O4 multifunctional nanohybrid material was synthesized and used for magnetic solid-phase extraction (MSPE) and photocatalytic degradation of trimethoprim and isoniazid, used together in tuberculosis treatment. All analyses were performed by high-performance liquid chromatography using a diode-array detection (HPLC-DAD) system. The synthesized material was characterized by X-ray diffraction spectroscopy (XRD), Raman spectroscopy, Fourier transform infrared (FTIR) spectroscopy, Brunauer-Emmett-Teller (BET) method, ζ-potential analysis, field-emission scanning electron microscopy (FE-SEM), and energy-dispersive X-ray spectroscopy (EDX). Important analytical parameters for the MSPE method such as the pH value of the sample solution, the volume of the sample solution, the amount of the sorbent, the type and volume of the elution solvent, and extraction time were optimized. The optimized MSPE method was then applied to different environmental waters and pharmaceutical samples. The recovery percentages for these samples were found to be between 95 and 107%. For trimethoprim and isoniazid, the limit of detections (LODs) were 0.055 and 0.145 and the limit of quantifications (LOQs) were 0.167 and 0.439 ng·mL-1, respectively. It was observed that â¼100% of trimethoprim and isoniazid active components were photocatalytically removed from the g-C3N4@TiO2@Fe3O4 nanohybrid material in â¼120 min under UV light.
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There are limited data about humoral response to vaccine in Behçet's syndrome (BS). We compared SARS-CoV-2 antibody response after two doses of inactivated (Sinovac/CoronaVac) or mRNA (Pfizer/BioNTech) vaccines in patients with BS and healthy controls (HCs). We studied 166 (92M/74F) patients with BS (mean age: 42.9 ± 9.6 years) and 165 (75M/90F) healthy controls (mean age: 42.4 ± 10.4 years), in a single-center cross-sectional design between April 2021 and October 2021. A total of 80 patients with BS and 89 HCs received two doses of CoronaVac, while 86 patients with BS and 76 HCs were vaccinated with BioNTech. All study subjects had a negative history for COVID-19. Serum samples were collected at least 21 days after the second dose of the vaccine. Anti-spike IgG antibody titers were measured quantitatively using a commercially available immunoassay method. We found that the great majority in both patient and HC groups had detectable antibodies after either CoronaVac (96.3% vs 100%) or BioNTech (98.8% vs 100%). Among those vaccinated with CoronaVac, BS patients had significantly lower median (IQR) titers compared to HCs [36.5 (12.5-128.5) vs 102 (59-180), p < 0.001]. On the other hand, antibody titers did not differ among patients with BS and HCs who were vaccinated with BioNTech [1648.5 (527.0-3693.8) vs 1516.0 (836.3-2599.5), p = 0.512). Among different treatment regimen subgroups in both vaccine groups, those who were using anti-TNF-based treatment had the lowest antibody titers. However, the difference was statistically significant only among those vaccinated with CoronaVac. Among patients vaccinated with BioNTech, there was no statistically significant difference between different treatment regimen groups. Compared to inactivated COVID-19 vaccine, mRNA-based vaccine elicited higher antibody titers among BS patients. Only in the CoronaVac group, patients especially those using anti-TNF agents were found to have low titers compared to healthy subjects. BS patients vaccinated with BioNTech were found to have similar seroconversion rates and antibody levels compared to healthy controls. Further studies should assess whether the low antibody titers are associated with diminished protection against COVID-19 in both vaccine groups.
Subject(s)
Behcet Syndrome , COVID-19 , Viral Vaccines , Adult , Antibodies, Viral , Antibody Formation , COVID-19/prevention & control , COVID-19 Vaccines , Cross-Sectional Studies , Humans , Middle Aged , RNA, Messenger , SARS-CoV-2 , Tumor Necrosis Factor Inhibitors , Vaccines, Inactivated , Viral Vaccines/adverse effectsABSTRACT
A new oxime compound, 4-(benzimidazolisonitrosoacetyl)biphenyl (BIBP) was synthesized and used as a complexing agent in this study to preconcentrate trace amounts of Pb(II) ions with vortex-assisted restricted access-based supramolecular solvent microextraction (RA/SUPRAS-LPME) method. The new complexing agent was characterized by a combination of elemental analyses, Proton Nuclear Magnetic Resonance (1H- NMR), Carbon-13 Nuclear Magnetic Resonance (13C NMR) and Fourier Transform Infrared spectroscopy (FT-IR) and techniques. Extraction of the complex which was formed at pH 8.0 was done by using a supramolecular solvent phase of tetrahydrofuran (THF) and 1-decanol. A microsampling flame atomic absorption spectrophotometer was used to measure the lead ion concentrations of the extract. The method optimized and the optimum experimental conditions were found as; pH = 8, amount of the ligand 2,25 mg, supramolecular solvent volume 50 µL, sample volume 20 mL and vortex time 3 min. The limit of detection (LOD), limit of quantification (LOQ) were calculated as 0.69 µg L-1 and 2.29 µg L-1, respectively. Linear range was found between 15.1 µg L-1 and 606 µg L-1. The developed method was applied to Pb(II) determination in real samples after evaluating the accuracy by using the TMDA-53.3 fortified environmental water sample as certified reference material.
Subject(s)
Liquid Phase Microextraction , Biphenyl Compounds , Ions , Lead , Liquid Phase Microextraction/methods , Solvents/chemistry , Spectrophotometry, Atomic/methods , Spectroscopy, Fourier Transform InfraredABSTRACT
Scientists, doctors, engineers, and even entire societies have become aware of the seriousness of the COVID-19 infection and are taking action quickly, using all the tools from protection to treatment against coronavirus SARS-CoV-2. Especially in this sense, scientific approaches and materials using nanotechnology are frequently preferred. In this review, we focus on how nanoscience and nanotechnology approaches can be used for protective equipment, diagnostic and treatment methods, medicine, and vaccine applications to stop the coronavirus SARS-CoV-2 and prevent its spread. SARS-CoV-2, which itself can be considered as a core-shell nanoparticle, can interact with various materials around it and remain bound for variable periods of time while maintaining its bioactivity. These applications are especially critical for the controlled use of disinfection systems. One of the most important processes in the fight against coronavirus is the rapid diagnosis of the virus in humans and the initiation of isolation and treatment processes. The development of nanotechnology-based test and diagnostic kits is another important research thrust. Nanotechnological therapeutics based on antiviral drug design and nanoarchitecture vaccines have been vital. Nanotechnology plays critical roles in the production of protective film surfaces for self-cleaning and antiviral masks, gloves, and laboratory clothes. An overview of literature studies highlighting nanotechnology and nanomaterial-based approaches to combat SARS-CoV-2 is presented.
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Surface-enhanced Raman scattering (SERS) is a powerful analytical tool for label-free analysis that has found a broad spectrum of applications in material, chemical, and biomedical sciences. In recent years, a great interest has been witnessed in the rational design of SERS substrates to amplify Raman signals and optionally allow for the selective detection of analytes, which is especially essential and challenging for biomedical applications. In this study, hard templating of noble metals is proposed as a novel approach for the design of one-component tailor-made SERS platforms. Porous Au microparticles were fabricated via dual ex situ adsorption of Au nanoparticles and in situ reduction of HAuCl4 on mesoporous sacrificial microcrystals of vaterite CaCO3. Elimination of the microcrystals at mild conditions resulted in the formation of stable mesoporous one-component Au microshells. SERS performance of the microshells at very low 0.4 µW laser power was probed using rhodamine B and bovine serum albumin showing enhancement factors of 2 × 108 and 8 × 108, respectively. The proposed strategy opens broad avenues for the design and scalable fabrication of one-component porous metal particles that can serve as superior SERS platforms possessing both excellent plasmonic properties and the possibility of selective inclusion of analyte molecules and/or SERS nanotags for highly specific SERS analysis.
Subject(s)
Gold , Metal Nanoparticles , Serum Albumin, Bovine , Spectrum Analysis, RamanABSTRACT
In the presented study, the usability of hydrolytic enzyme immobilized magnetic nanoparticles as an extraction agent for the microextraction of metal ions from food samples was investigated. α-amylase modified magnetic carbon nanotubes (α-amylase-Fe3O4/MWCNTs) was used as an extraction agent for direct microextraction of trace arsenic from food sample phase into liquid phase medium prior to its ICP-MS determination. In extraction studies using hydrolytic enzymes, it is impossible to recover the free soluble enzyme after extraction without losing its activity. In our study, this problem was overcome by immobilizing the hydrolytic enzyme on magnetic support. In this way, α-amylase-Fe3O4/MWCNTs as an extraction agent with a reuse property of at least six times was used. α-amylase-Fe3O4/MWCNTs was characterized by FT-IR, XRD, SEM, SEM-EDX, VSM, TGA, and DTG techniques. Optimization of the presented method was performed using 1568 A rice flour certified reference material. Analytical parameters such as type of hydrolytic enzyme, pH and volume of the aqueous phase, extraction temperature and ultrasonic irridation time were optimized. The microextraction step was performed in ultrasonic water bath within only â¼15 min. Limit of detection (LOD), limit of quantification (LOQ) and relative standard deviation (RSD %) values for the developed method were found to be 14.3 µg kg-1, 47.3 µg kg-1 and 7.5%, respectively. The method was successfully applied to the analysis of arsenic contents of different rice and flour samples.
Subject(s)
Liquid Phase Microextraction , Magnetite Nanoparticles , Nanotubes, Carbon , Hydrolysis , Limit of Detection , Magnetics , Solid Phase Extraction , Spectroscopy, Fourier Transform InfraredABSTRACT
A magnetic solid phase extraction (MSPE) coupled with high-performance liquid chromatography-diode array detection (HPLC-DAD) methodology was developed for the determination of chloramphenicol (CP) and tetracycline (TET) antibiotic residues in milk samples. As a solid phase sorbent, C-nanofiber coated magnetic nanoparticles were synthesized and extensively characterized using Field Emission Scanning Electron Microscopy (FE-SEM), Raman Spectroscopy and X-ray Powder Diffraction (XRD) analysis. Experimental variables of MSPE method for both antibiotic analytes were investigated and optimized systematically. After MSPE, the linear range for both the analytes (r2 > 0.9954) were obtained in a range 10.0-600.0 ng mL-1. The limit of detections (LODs) for CP and TET were 3.02 and 3.52 ng mL-1, respectively while RSDs % were below than 4.0%. Finally, the developed method based on MPSE-HPLC-DAD was applied to real milk samples to quantify the antibiotic residues. Recovery values for each antibiotic compound were found in the range of 94.6-105.4% (n = 3) by using spiked model solution.
Subject(s)
Chloramphenicol , Nanofibers , Animals , Anti-Bacterial Agents , Chromatography, High Pressure Liquid , Limit of Detection , Magnetic Phenomena , Milk , Solid Phase ExtractionABSTRACT
A new analyte separation and preconcentration method for the trace determination of antidepressant drugs, Fluoxetine (FLU) and Citalopram (CIT) in urine and wastewaters, was developed based on HPLC-DAD analysis after magnetic solid phase extraction (MSPE). In the proposed method, FLU and CIT were retained on the newly synthetized magnetic sorbent (Fe3O4@PPy-GO) in the presence of buffer (pH 10.0) and then were desorbed into a lower volume of acetonitrile prior to the chromatographic determinations. Before HPLC analysis, all samples were filtered through a 0.45 µm PTFE filter. Experimental parameters such as interaction time, desorption solvent and volume, and pH were studied and optimized in order to establish the detection limit, linearity, enrichment factor and other analytical figures of merit under optimum operation conditions. In the developed method, FLU and CIT were analyzed by diode array detector at the corresponding maximum wavelengths of 227 and 238 nm, respectively, by using an isocratic elution of 60% pH 3.0 buffer, 30% acetonitrile, and 10% methanol. By using the optimum conditions, limit of detections for FLU and CIT were 1.58 and 1.43 ng mL-1, respectively, while the limit of quantifications was 4.82 and 4.71 ng mL-1, respectively. Relative standard deviations (RSD%) for triplicate analyses of model solutions containing 100 ng mL-1 target molecules were found to be less than 5.0 %. Finally, the method was successfully applied to urine (both simulated and real healthy human) and wastewater samples, and quantitative results were obtained in recovery experiments.
Subject(s)
Antidepressive Agents/analysis , Chromatography, Liquid/methods , Citalopram/analysis , Fluoxetine/analysis , Spectrophotometry, Ultraviolet/methods , Wastewater/chemistry , Water Pollutants, Chemical/analysis , Antidepressive Agents/urine , Citalopram/urine , Fluoxetine/urine , Humans , Limit of Detection , Solid Phase Extraction/methods , Solvents/chemistry , Water Pollutants, Chemical/urineABSTRACT
The importance of magnetic nanomaterials and magnetic hybrid materials, which are classified as new generation materials, in analytical applications is increasingly understood, and research on the adaptation of these materials to analytical methods has gained momentum. Development of sample preparation techniques and sensor systems using magnetic nanomaterials for the analysis of inorganic, organic and biomolecules in biological samples, which are among the samples that analytical chemists work on most, are among the priority issues. Therefore in this review, we focused on the use of magnetic nanomaterials for the bioanalytical applications including inorganic and organic species and biomolecules in different biological samples such as primarily blood, serum, plasma, tissue extracts, urine and milk. We summarized recent progresses, prevailing techniques, applied formats, and future trends in sample preparation-analysis methods and sensors based on magnetic nanomaterials (Mag-NMs). First, we provided a brief introduction of magnetic nanomaterials, especially their magnetic properties that can be utilized for bioanalytical applications. Second, we discussed the synthesis of these Mag-NMs. Third, we reviewed recent advances in bioanalytical applications of the Mag-NMs in different formats. Finally, recently literature studies on the relevance of Mag-NMs for bioanalysis applications were presented.