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A one-shot CO2 laser-based strategy to generate conductive reduced graphene oxide (rGO) decorated with nanoceria (nCe) is proposed. The 2D/0D rGO-nCe films, integrated as catalytic sensing layers in paper-based sensors, were employed for on-site monitoring of indoor fogging treatments against Listeria monocytogenes (Lm), a ubiquitous pathogenic bacterium. The rGO-nCe laser-assisted synthesis was optimized to preserve the rGO film morphological and electron-transfer features and simultaneously integrate catalytic nCe. The films were characterized by microscopical (SEM), spectroscopical (EDX, Raman, and FTIR), and electrochemical techniques. The most performing film was integrated into a nitrocellulose substrate, and the complete sensor was assembled via a combination of xurography and stencil printing. The rGO-nCe sensor's catalytic activity was proved toward the detection of H2O2, obtaining sensitive determination (LOD = 0.3 µM) and an extended linear range (0.5-1500 µM). Eventually, the rGO-nCe sensor was challenged for the real-time continuous monitoring of hydrogen peroxide aerosol during no-touch fogging treatment conducted following the EU's recommendation for biocidal product use. Treatment effectiveness was proved toward three Lm strains characterized by different origins, i.e., type strain ATCC 7644, clinical strain 338, and food strain 641/6II. The sensor allows for discrimination and quantification treatments at different environmental biocidal amounts and fogging times, and correlates with the microbiological inhibition, promoting the proposed sensor as a useful tool to modulate and monitor no-touch treatments.
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Desinfecção , Grafite , Peróxido de Hidrogênio , Lasers , Listeria monocytogenes , Papel , Grafite/química , Peróxido de Hidrogênio/química , Listeria monocytogenes/efeitos dos fármacos , Listeria monocytogenes/isolamento & purificação , Desinfecção/métodos , Cério/química , Limite de Detecção , Técnicas Eletroquímicas/métodos , Técnicas Eletroquímicas/instrumentação , CatáliseRESUMO
Lysozyme is widely known to promote the formation of condensed silica networks from solutions containing silicic acid, in a reproducible and cost-effective way. However, little is known about the fate of the protein after the formation of the silica particles. Also, the relative arrangement of the different components in the resulting material is a matter of debate. In this study, we investigate the nature of the protein-silica interactions by means of solid-state nuclear magnetic resonance spectroscopy, small-angle X-ray scattering, and electron microscopy. We find that lysozyme and silica are in intimate contact and strongly interacting, but their interaction is neither covalent nor electrostatic: lysozyme is mostly trapped inside the silica by steric effects.
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Muramidase , Dióxido de Silício , Muramidase/química , Proteínas , Ácido Silícico , Dióxido de Silício/químicaRESUMO
Calcium silicate hydrate (C-S-H) is the main binding product of ordinary Portland concrete (OPC). Unfortunately, OPC production generates â¼5% of all anthropomorphic CO2. Among the most promising green alternatives, magnesium silicate hydrate (M-S-H) is a colloidal gel equivalent to C-S-H which exhibits weaker mechanical properties. Here we investigated the effect of the inclusion of aluminosilicate nanoclays (HNTs) on the microstructure of the silicate hydrate gels as a strategy to ultimately improve their mechanical properties. The microstructure of C-S-H and M-S-H gels synthesized with and without carboxylic or polycarboxylic functionalised HNTs (HNT-COOH, HNT-PAA) was investigated by a multi-technique approach including small- and wide-angle X-ray scattering (SWAXS) and scanning electron microscopy (SEM). The results indicate that, during C-S-H formation in solution, HNTs decrease the size of the disk-like globules with little influence on the spacing of calcium silicate layers. In the case of M-S-H, the presence of functionalised HNTs has a reduced effect on the hydrate structure as a result of the weaker interaction of the carboxylic moieties with Mg2+ ions. SEM investigation on the synthesized composites shows that HNT-PAA are better included in the hydration products. Moreover, in the proximity of the PAA functionalised surfaces, less extended aggregates are formed. The morphology at the micron scale for M-S-H and C-S-H with HNT-COOH is conserved.
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INTRODUCTION: Atherosclerosis causes a chronic reduction of vascularization with consequent impairment of the performance of organs, like the brain or muscles, which determines the functional and cognitive decline of the elderly and their ability to respond to acute stressful condition. Therefore, our aim was to evaluate if ankle brachial index (ABI) could effectively be a determinant of in-hospital functional status and complications in elderly hospitalized patients. METHODS: This is a monocentric cross-sectional study of 189 patients aged 65 years or older. The study was undertaken at the Internal Medicine ward of Niguarda Hospital in Milan. ABI (BOSO ABY-System 100) and in-hospital status (activities of daily living, ADL and instrumental activities of daily living, IADL) were collected on the second day of hospitalization. Complications (falls and delirium episodes) were also recorded during the whole hospitalization period. RESULTS: The average age of patients was 79.3 ± 6.9 years. Among outcomes, only ADL (r = 0.192, p = 0.007) and IADL score (r = 0.200, p = 0.005) showed significant correlation with ABI. Moreover, during the subsequent logistic regression, ABI remained among the statistically significant determinants of both scores (ß = 0.231, p = 0.013 and ß = 0.314, p = 0.001, respectively). CONCLUSIONS: The main result of our study is the finding of ABI as a significant determinant of acute in-hospital functional impairment (evaluated as ADL and IADL scores). The continuous exposure of the brain and muscles to the reduced perfusions induced by vascular atherosclerosis, probably determined the reduced ability to respond to stressful conditions.
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Atividades Cotidianas , Índice Tornozelo-Braço , Idoso , Idoso de 80 Anos ou mais , Estudos Transversais , Estado Funcional , Hospitalização , Hospitais , HumanosRESUMO
A new green and effective sonochemical liquid-phase exfoliation (LPE) is proposed wherein a flavonoid compound, catechin (CT), promotes the formation of conductive, redox-active, water-phase stable graphene nanoflakes (GF). To maximize the GF-CT redox activity, the CT concentration and sonication time have been studied, and the best performing nanomaterial-fraction selected. Physicochemical and electrochemical methods have been employed to characterize the morphological, structural, and electrochemical features of the GF-CT nanoflakes. The obtained GF intercalated with CT exhibits fully reversible electrochemistry (ΔEp = 28 mV, ipa/ipc = â1) because of the catecholic adducts. GF-CT-integrated electrochemistry was generated directly during LPE of graphite, with no need of graphene oxide production, nor activation steps, electropolymerization, or ex-post functionalization. The GF-CT electro-mediator ability has been proven towards hydrazine (HY) and ß-nicotinamide adenine dinucleotide (NADH) by simply drop-casting the redox-material onto screen-printed electrodes. GF-CT-based electrodes by using amperometry exhibited high sensitivity and extended linear ranges (HY: LOD = 0.1 µM, L.R. 0.5-150 µM; NADH: LOD = 0.6 µM, L.R. 2.5-200 µM) at low overpotential (+ 0.15 V) with no electrode fouling. The GF-CT electrodes are performing significantly better than commercial graphite electrodes and graphene nanoflakes exfoliated with a conventional surfactant, such as sodium cholate. Recoveries of 94-107% with RSD ≤ 8% (n = 3) for determination of HY and NADH in environmental and biological samples were achieved, proving the material functionality also in challenging analytical media. The presented GF-CT is a new functional redox-active material obtainable with a single-pot sustainable strategy, exhibiting standout properties particularly prone to (bio)sensors and cutting-edge device development.
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GrafiteRESUMO
A polystyrene ELISA plate (EP) modified with a thin film based on gold nanoseeds (AuSDs) assembled onto polydopamine (PDA) is proposed. The nanodecorated film (PDA@AuSD) allows to evaluate the polyphenols antioxidant capacity (AOC) through a colorimetric approach based on a seed-mediated growth strategy. Polyphenols, in the presence of the nanodecorated (PDA@AuSD) surfaces are able to drive an increase in size of the AuSDs according to their AOC; this produces an increase of the localized surface plasmon resonance (LSPR; maximum at λ ~ 550 nm) that is taken as analytical signal. The PDA@AuSD EP manufacturing shows good intraplates repeatability (RSD ≤ 6.6%, n = 96 wells) and interplates reproducibility (RSD ≤ 7.4%, n = 748 wells), resulting stable for 1 year. The AuSDs growth kinetic has been studied using 11 polyphenols belonging to different chemical classes and 4 different food samples. The PDA@AuSD film is able to return quantitative information on the AOC of food polyphenols. Good repeatability (RSD ≤ 5.7%, n = 12 EP wells) and reproducibility (RSD ≤ 8.1%, n = 12 EP wells) was achieved, with acceptable linear correlation coefficients (R2 ≥ 0.990) and useful limits of detection (LODs ≤ 2.5 10-5 mol L-1). The samples analyzed with the PDA@AuSD device have been successfully ordered according to their AOC in agreement with conventional optical methods. The PDA@AuSD plate allows multiple measurements (96 wells per EP) with a one-step strategy, overcoming the limitations related to the use of colloidal nanoparticles; in addition, since absorbance is measured after washing, it is not affected by sample color or turbidity. Graphical abstract Schematic representation of ELISA plate (EP) modified with polydopamine (PDA) film decorated with gold nanoseeds (AuSD). The colorimetric assay, to evaluate the antioxidant capacity, is based on the AuSD growth mediated by polyphenols, resulting in absorbance increase at 550 nm (ΔAbs550), which is employed as analytical signal.
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Colorimetria/métodos , Sequestradores de Radicais Livres/análise , Indóis/química , Nanopartículas Metálicas/química , Polímeros/química , Polifenóis/análise , Cacau/química , Suplementos Nutricionais/análise , Ouro/química , Limite de Detecção , Olea/química , Extratos Vegetais/análise , Folhas de Planta/química , Reprodutibilidade dos Testes , Ressonância de Plasmônio de Superfície , Chá/químicaRESUMO
A high-performance screen-printed electrode (SPE) based nanocomposite sensor integrating tungsten disulfide (WS2) flakes decorated with catechin-capped gold nanoparticles (AuNP-CT) and carbon black (CB) has been developed. The excellent antifouling properties of WS2 decorated with AuNP-CT into a high conductivity network of CB results in high selectivity, sensitivity, and reproducibility for the simultaneous determination of hydroxycinnamic acid (hCN) structural analogs: caffeic (CF), sinapic (SP), and p-coumaric acids (CM). Using differential pulse voltammetry (DPV), the target hCNs resulted in three well-resolved oxidation peaks at SPE-CB-WS2/AuNP-CT sensor. Excellent antifouling performance (RSD ip,a ≤ 3%, n = 15 for three analytes' simultaneous measure) and low detection limits (CF 0.10 µmol L-1; SP, 0.40 µmol L-1; CM, 0.40 µmol L-1) are obtained despite the analyzed compounds having a high passivation tendency towards carbon-based sensors. The SPE-CB-WS2/AuNP-CT sensor was successfully applied to determine CF, SP, and CM in food samples with good precision (RSD ≤ 4%, n = 3) and recoveries (86-109%; RSD ≤ 5%, n = 3). The proposed sensor is the first example exploiting the simultaneous determination of these compounds in food samples. Given its excellent electrochemical performance, low cost, disposability, and ease of use, this SPE-CB-WS2/AuNP-CT nanocomposite sensor represents a powerful candidate for the realization of electrochemical devices for the determination of (bio)compounds with high passivation tendency. Graphical abstract.
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Synthesis of the new scorpiand ligand L composed of a [9]aneN3 macrocyclic ring bearing a CH2CH2NHCH2-anthracene tail is reported. L forms both cation (Zn2+) and anion (phosphate, benzoate) complexes. In addition, the zinc complexes of L bind these anions. The equilibrium constants for ligand protonation and complex formation were determined in 0.1 M NaCl aqueous solution at 298.1 ± 0.1 K by means of potentiometric (pH-metric) titrations. pH Controlled coordination/detachment of the ligand tail to Zn2+ switch on and off the fluorescence emission from the anthracene fluorophore. Accordingly, L is able to sense Zn2+ in the pH range 6-10 down to nM concentrations of the metal ion. L can efficiently sense Zn2+ even in the presence of large excess of coordinating anions, such as cyanide, sulphide, phosphate and benzoate, despite their ability to bind the metal ion.
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Antracenos/química , Compostos Macrocíclicos/química , Água/química , Zinco/análise , Ânions , Fluorescência , Ligação de Hidrogênio , Concentração de Íons de Hidrogênio , Ligantes , Prótons , Soluções , Espectrometria de FluorescênciaRESUMO
The Zr4+ complexes with desferrioxamine (H3DFO) and its derivatives are the only 89Zr-based imaging agents for proton emission tomography (PET) that have been used so far in clinical trials. Nevertheless, a complete speciation of the Zr4+/H3DFO system in solution has never been performed and the stability constants of the relevant complexes are still unknown. Here we report, for the first time, the speciation of this system in water, performed by potentiometric titrations, and the determination of the stability constants of all complexes formed in the pH range 2.5-11.5. Surprisingly, although desferrioxamine gives rise to very stable 1:1 complexes with Zr4+ (logK = 36.14 for Zr4+ + DFO3- = [ZrDFO]+), 2:2 and 2:3 ones are also formed in solution. Depending on the conditions, these binuclear complexes can be main species in solution. These results were corroborated by small-angle X-ray scattering (SAXS) and MALDI mass spectrometry analyses of complex solutions. Information on complex structures was obtained by means of density functional theory (DFT) calculations.
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Complexos de Coordenação/química , Desferroxamina/química , Zircônio/química , Quelantes/química , Concentração de Íons de Hidrogênio , Marcação por Isótopo , Tomografia por Emissão de Pósitrons , Compostos Radiofarmacêuticos/química , Análise EspectralRESUMO
BACKGROUND: The measurement of circulating free light chain (FLC) is essential in the diagnosis, prognostic stratification and evaluation of response to therapy in light chain (AL) amyloidosis. For more than 10 years, this has been done with an immunonephelometric assay based on polyclonal antibodies (Freelite), and cutoffs for staging and response assessment have been validated with this method. Recently, a new assay based on monoclonal antibodies (N latex FLC) has been marketed in Europe. METHODS: We evaluated and compared the clinical performance of the two assays in 426 patients with newly diagnosed AL amyloidosis. RESULTS: We found suboptimal agreement between the two methods, with differences between values obtained with the Freelite and N latex FLC assays increasing with the concentration of clonal FLC. The diagnostic sensitivity of the Freelite (82%) and N latex FLC (84%) assays was similar, and both improved to 98% in combination with serum and urine immunofixation. The concentration of FLC measured with both methods had prognostic significance. Less pronounced decreases in FLC best predicted improved survival with the N latex FLC assay (33% vs. 50%), and there was poor concordance (84%) in discrimination of responders. CONCLUSIONS: The two assays have similar diagnostic and prognostic performance. However, they are not interchangeable, and follow-up should be done with either one. New response criteria are needed for the N latex FLC assay.
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Amiloidose/diagnóstico , Imunoensaio/normas , Cadeias Leves de Imunoglobulina/sangue , Idoso , Anticorpos Monoclonais/imunologia , Feminino , Humanos , Cadeias Leves de Imunoglobulina/imunologia , Amiloidose de Cadeia Leve de Imunoglobulina , Látex/química , Masculino , Pessoa de Meia-Idade , Nefelometria e Turbidimetria/normas , PrognósticoRESUMO
The detection and quantification of amyloidogenic monoclonal light chains are necessary for the diagnosis and evaluation of response to treatment in AL amyloidosis. However, the amyloid clone is often small and difficult to detect. We report the case of a 68-year-old man who was referred to our Center in April 2013 after syncope and the identification of left ventricular hypertrophy at echocardiography, suspected for amyloidosis. A commercial agarose gel electrophoresis immunofixation (IFE) did not reveal monoclonal components in serum and urine. The κ serum free light chain (FLC) concentration was 21.5 mg/L, λ 33 mg/L (κ/λ ratio 0.65), NT-proBNP 9074 ng/L (u.r.l. <332 ng/L) and an echocardiogram confirmed characteristic features of amyloidosis. The abdominal fat aspiration was positive and the amyloid typing by immune-electron microscopy revealed λ light chains deposits. A high-resolution (hr) IFE of serum and urine showed a faint monoclonal λ component in the urine. A bone marrow biopsy showed 8% plasma cells (BMPC) and a kappa/lambda light-chain restriction with λ light chain on immunofluorescence. The diagnosis of AL (λ) amyloidosis with cardiac involvement was made. In May 2013, patient was started on cyclophosphamide, bortezomib and dexamethasone. After six cycles, serum and urine hr-IFE were negative, the bone marrow biopsy showed 3% BMPC without light chain restriction by immunofluorescence, and a decrease of NT-proBNP was observed (5802 ng/L).Thus, treatment was discontinued. In this patient the amyloid clone could be detected only by in house hr-IFE of urine and bone marrow examination. The detection of the small dangerous amyloidogenic clone should be pursued with a combination of high-sensitivity techniques, including assessment of BMPC clonality. Studies of novel tools, such as mass spectrometry on serum and next-generation flow cytometry analysis of the bone marrow, for detecting plasma cell clones in AL amyloidosis and other monoclonal light chain-related disorders are warranted.
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Amiloidose/diagnóstico , Cadeias kappa de Imunoglobulina/análise , Cadeias lambda de Imunoglobulina/análise , Idoso , Amiloidose/sangue , Amiloidose/patologia , Amiloidose/urina , Eletroforese em Gel de Ágar , Humanos , Hipertrofia Ventricular Esquerda/diagnóstico , Imunoeletroforese , Masculino , Plasmócitos/patologia , Síncope/diagnósticoRESUMO
BACKGROUND: The measurement of circulating free light chains (FLC) is of utmost importance in immunoglobulin light chain (AL) amyloidosis, being a fundamental part of the diagnostic workup, prognostic stratification and assessment of response to therapy. Renal failure is a common feature of AL amyloidosis and can considerably affect the concentration of FLC. METHODS: We assessed the impact of renal failure on the clinical performance of the Freelite assay in 982 consecutive, newly diagnosed patients with AL amyloidosis, 822 with estimated glomerular filtration rate (eGFR) ≥30 mL/min/1.73 m2, and 160 with eGFR <30 mL/min/1.73 m2. RESULTS: The diagnostic sensitivity of the κ/λ FLC ratio was lower for λ amyloidogenic FLC in patients with renal failure (81% vs. 60%, p<0.001) and the FLC concentration had no independent prognostic significance in patients with severe renal dysfunction. However, FLC response to chemotherapy could still discriminate patients with better outcome. CONCLUSIONS: Renal failure is a relevant interference factor when using the Freelite assay for the identification of the amyloidogenic light chain and for prognostic assessment in patients with AL amyloidosis and renal failure.
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Amiloidose/diagnóstico , Cadeias kappa de Imunoglobulina/sangue , Cadeias lambda de Imunoglobulina/sangue , Insuficiência Renal/diagnóstico , Idoso , Amiloidose/sangue , Amiloidose/fisiopatologia , Amiloidose/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Prognóstico , Insuficiência Renal/sangue , Insuficiência Renal/fisiopatologia , Insuficiência Renal/terapiaRESUMO
Bio-based nanostructured molecularly imprinted polymers (nano-MIPs), also known as 'plastibodies', have a real potential to be used as alternatives to natural antibodies. These nanostructures have recently gained significant attention for diagnostic and therapeutic purposes. In this context, we have developed polynorepinephrine (PNE)-based nano-MIPs using an eco-friendly one-pot process for the sensitive and selective detection of a model biomolecule, immunoglobulin IgG1. We first investigated non-imprinted nanostructures (nano-NIPs) based on polydopamine as reference material, using DLS, SEM, and UV-Vis spectroscopy. Subsequently, PNE scaffolds were characterized, both in the form of nano-NIPs and nano-MIPs. Concerning nano-MIPs, we used the epitope-directed imprinting technology to create binding cavities using a small peptide from the constant region of IgG1 as a template. Nano-MIPs were initially immobilized on a sensing surface to assess their binding capacity via surface plasmon resonance (SPR) spectroscopy. This strategy showed very good sensitivity, outperforming planar PNE-based imprinted films while keeping a high selectivity even in complex biological matrices such as human serum. Furthermore, we confirmed the presence of selective binding sites on nano-MIPs by flowing them, along with nano-NIPs, through a microfluidic SPR system, where they interact with the covalently immobilized analyte. This approach resulted in a good imprinting factor of 4.5. Overall, this study underscores the broad potential of these nanostructures as a viable and reusable alternative to antibodies across a variety of bioanalytical, biochemical, and immunohistochemistry analysis techniques.
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Técnicas Biossensoriais , Impressão Molecular , Receptores Artificiais , Humanos , Impressão Molecular/métodos , Ressonância de Plasmônio de Superfície , Imunoglobulina G , Norepinefrina , BiopolímerosRESUMO
Herein, a strategy to stamp laser-produced reduced graphene oxide (rGO) onto flexible polymers using only office-grade tools, namely, roll-to-roll thermal stamping, is proposed, proving for the first time its effectiveness for direct bioelectrocatalysis. This straightforward, scalable, and low-cost approach allows us to overcome the limits of the integration of laser-induced rGO-films in bioanalytical devices. Laser-produced rGO has been thermally stamped (TS) onto different polymeric substrates (PET, PVC, and EVA) using a simple roll-laminator; the obtained TS-rGO films have been compared with the native rGO (untransferred) via morphochemical and electrochemical characterization. Particularly, the direct electron transfer (DET) reaction between fructose dehydrogenase (FDH) and TS-rGO transducers has been investigated, with respect to the influence of the amount of enzyme on the catalytic process. Remarkable differences have been observed among TS-rGO transducers; PET proved to be the elective substrate to support the transfer of the laser-induced rGO, allowing the preservation of the morphochemical features of the native material and returning a reduced capacitive current. Noteworthily, TS-rGOs ensure superior electrocatalysis using a very low amount of FDH units (15 mU). Eventually, TS-rGO-based third-generation complete enzymatic biosensors were fabricated via low-cost benchtop technologies. TS-rGOPET exhibited bioanalytical performances superior to the native rGO, allowing a sensitive (0.0289 µA cm-2 µM-1) and reproducible (RSD = 3%, n = 3) d-fructose determination at the nanomolar level (LOD = 0.2 µM). TS-rGO exploitability as a point-of-need device was proved via the monitoring of d-fructose during banana (Musa acuminata) postharvest ripening, returning accurate (recoveries 110-90%; relative error -13/+1%) and reproducible (RSD ≤ 7%; n = 3) data.
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Grafite , Lasers , Grafite/química , Transporte de Elétrons , Técnicas Eletroquímicas , Desidrogenases de Carboidrato/química , Desidrogenases de Carboidrato/metabolismo , Técnicas Biossensoriais , OxirreduçãoRESUMO
The possibility to print electronics by means of office tools has remarkedly increased the possibility to design affordable and robust point-of-care/need devices. However, conductive inks suffer from low electrochemical and rheological performances limiting their applicability in biosensors. Herein, a fast CO2 laser approach to activate printed carbon inks towards direct enzymatic bioelectrocatalysis (3rd generation) is proposed and exploited to build biosensors for D-fructose analysis in biological fluids. The CO2 laser treatment was compared with two lab-grade printed transducers fabricated with solvent (SB) and water (WB) based carbon inks. The use of the laser revealed significant morpho-chemical variations on the printed inks and was investigated towards enzymatic direct catalysis, using Fructose dehydrogenase (FDH) integrated into entirely lab-produced biosensors. The laser-driven activation of the inks unveils the inks' direct electron transfer (DET) ability between FDH and the electrode surface. Sub-micromolar limits of detection (SB-ink LOD = 0.47 µM; WB-ink LOD = 0.24 µM) and good linear ranges (SB-ink: 5-100 µM; WB-ink: 1-50 µM) were obtained, together with high selectivity due to use of the enzyme and the low applied overpotential (0.15 V vs. pseudo-Ag/AgCl). The laser-activated biosensors were successfully used for D-fructose determination in complex synthetic and real biological fluids (recoveries: 93-112%; RSD ≤8.0%, n = 3); in addition, the biosensor ability for continuous measurement (1.5h) was also demonstrated simulating physiological D-fructose fluctuations in cerebrospinal fluid.
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BACKGROUND: A raised serum TSH in the absence of a clear etiology, or "unexplained hyperthyrotropinemia" (UH), can be challenging for clinicians. The aim of the present study was to evaluate potential strategies aimed at a clinical and biochemical characterization of UH patients. METHODS: We compared 36 patients with UH with a control group of 14 patients with chronic autoimmune thyroiditis (CAT) and subclinical hypothyroidism. The two groups were compared in terms of the following: (i) the rate of normalization of TSH after repeating with another assay; (ii) the rate of normalization of TSH over time with the same assay; (iii) the reduction in TSH after precipitation with polyethilenglycole (PEG); and (iv) free thyroxine (FT4) levels. RESULTS: Similar TSH levels were observed in UH [5.65 (5.21-6.37)] and CAT [5.62 (5.17-8.50)] (p = 0.489). TSH measurement with another assay method showed a normal TSH value in 41.9% of UH vs. 46.1% of CAT patients (p = 0.797). After repeating the TSH measurement in time with the same assay method, an increased TSH value was confirmed in all cases, in both groups (0% in the UH group vs. 0% in the CAT group, p = 1.000). TSH recovery after PEG precipitation was similar in the two groups (% precipitable post-PEG: 68.75 ± 3.14 in UH vs. 68.67 ± 7.18 in CAT, p = 0.960). FT4 levels were similar in the two groups (FT4 1.02 ± 0.20 ng/dl in UH vs. 1.00 ± 0.20 ng/dl in CAT, p = 0.789). CONCLUSIONS: The results do not support the concept that laboratory interferences are more frequent in UH patients, suggesting that patients with UH should be managed in the same way as patients with CAT until proven otherwise.
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Among emerging layered materials, 2D transition metal dichalcogenides (TMDs) nanosheets (n-sheets) have received increasing attention for optoelectronics, energy storage, and, recently, for bioremediation and advanced biomedical applications; however, a lack of ecotoxicological in vivo studies is evident. Herein, for the first time, the potential nanotoxicity of liquid phase exfoliated Group VI TMDs n-sheets (MoS2, WS2, WSe2, and MoSe2) was comparatively investigated using zebrafish embryos (Z-EBs) as an in-vivo model. The 2D n-sheets were produced directly in aqueous-medium, the obtained n-sheets were characterized by scanning electron microscopy, Raman and visible spectroscopy, and their potential nanotoxicity was investigated by fish embryo test OECD TG 236. Chorionated and dechorionated embryos were used to assess the severity of TMD exposure. The survival rate, sublethal alteration during embryogenesis, hatching rate, and mortality were evaluated. TMDs n-sheets tend to adhere to the Z-EBs surface depending on their chemistry. Despite this, TMDs did not show lethal effects; weak sublethal effects were found for MoS2 and WSe2, while slight hatching delays were registered for MoSe2 and WSe2. The observed effects are attributable to the TMDs' tendency to interact with Z-EBs, because of the different chemistry. This work demonstrates how water-dispersed TMDs are potential eco/biocompatible materials.
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Molibdênio , Peixe-Zebra , Animais , Molibdênio/toxicidade , Materiais Biocompatíveis , Ecotoxicologia , MetaisRESUMO
The sensitivity of ELISA-based devices strongly depends on the right orientation of antibodies on the sensor surface. The aim of this work was to increase the analytical performance of a commercial ELISA-based medical device (VIDAS®), thanks to the specific orientation of antibodies on gold nanostructured disposables. For this purpose, fPSA VIDAS® assay was used as model and the disposable providing the antigen binding surface (SPR®) was functionalized with gold nanostructures coated with monovalent half-fragment antibodies (reduced IgG, rIgG). The functionalization of polystyrene SPRs® with gold nanostructures was achieved through a one-step incubation of gold dispersions in a mixture of non-toxic solvents. Five different concentrations of gold nanoparticles (NPs) were tested with a maximum fluorescence enhancement for NPs density around 3-8 *103 NPs/µm2 (752 ± 11 RFV vs 316 ± 5 RFV of bare SPRs®). The comparison of the dose-response curve obtained with commercial and gold coated-SPRs® revealed a significant improvement (p < 0.0001) of the analytical sensitivity of the VIDAS® system using nanostructured disposables. This improved version of SPRs® allows to distinguish small variations of fPSA concentrations opening the way to the application of this biomarker to other kinds of cancer as recently described in the literature.
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Técnicas Biossensoriais , Nanopartículas Metálicas , Ouro/química , Nanopartículas Metálicas/química , Anticorpos/química , Ensaio de Imunoadsorção EnzimáticaRESUMO
Rapid volatile organic compounds (VOCs) detection is a hot topic today; in this framework nanomaterials and their tailorable chemistry offer a plethora of compelling opportunities. In this work, Group VI transition metal dichalcogenides (TMDs, i.e., MoS2, WSe2, MoSe2, and WSe2) were functionalized with organic compounds (ellagic acid, tannic acid, catechin, and sodium cholate) able to assist their sonochemical exfoliation in water. The 16 resulting water-dispersed 2D hybrid inorganic/organic TMDs resulted in a few-layer nanoflakes conformation and were used to modify quartz crystal microbalances (QCMs) to equip an e-nose for VOCs determination. The ability of the sensors for the detection of VOCs was assessed on alcohols, terpenes, esters, and aldehydes; the responses were significatively different, confirming the synergic effect of TMD and the organic compound in the interaction with VOCs. The 16 sensors exhibited quantitative responses for VOCs (R2≥0.978) with fast signals recovery (<100 s) and repeatable (RSD ≤9.3%, n = 5), reproducible (RSD ≤12.8%, n = 3) and stable (RSD ≤14.6%, 3 months) signals. As proof of applicability, in an e-nose format, banana aroma evolution during post-harvest ripening was successfully monitored using the 2D TMDs-based sensors array. These data demonstrate that TMDs exfoliated in water with different organic compounds are sustainable functional nanomaterials, able to offer new opportunities in nano-bioelectronic applications.