Exploring the Potential of Invasive Species Sargassum muticum: Microwave-Assisted Extraction Optimization and Bioactivity Profiling.

Sargassum muticum (SM) poses a serious environmental issue since it is a fast-expanding invasive species occupying key areas of the European shoreline, disrupting the autochthonous algae species, and disturbing the ecosystem. This problem has concerned the general population and the scientific community. Nevertheless, as macroalgae are recognized as a source of bioactive molecules, the abundance of SM presents an opportunity as a raw material. In this work, response surface methodology (RSM) was applied as a tool for the optimization of the extraction of bioactive compounds from SM by microwave-assisted extraction (MAE). Five different parameters were used as target functions: yield, total phenolic content (TPC); and the antioxidant measurements of 2,2-diphenyl-1-picrylhydrazyl radical scavenging activity (DPPH), 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) diammonium salt (ABTS), and ß-carotene bleaching (BC). After the optimal extraction conditions were determined (time = 14.00 min; pressure = 11.03 bar; ethanol = 33.31%), the chemical composition and bioactivity of the optimum extract was evaluated to appraise its antioxidant capability to scavenge reactive species and as a potential antibacterial, antidiabetic, antiproliferation, and neuroprotective agent. The results lead to the conclusion that MAE crude extract has bioactive properties, being especially active as an antiproliferation agent and as a nitric oxide and superoxide radical scavenger.

The Impact of BDNF, NTRK2, NGFR, CREB1, GSK3B, AKT, MAPK1, MTOR, PTEN, ARC, and SYN1 Genetic Polymorphisms in Antidepressant Treatment Response Phenotypes.

This study aimed to investigate the influence of genetic variants in neuroplasticity-related genes on antidepressant treatment phenotypes. The BDNF-TrkB signaling pathway, as well as the downstream kinases Akt and ERK and the mTOR pathway, have been implicated in depression and neuroplasticity. However, clinicians still struggle with the unpredictability of antidepressant responses in depressed patients. We genotyped 26 polymorphisms in BDNF, NTRK2, NGFR, CREB1, GSK3B, AKT, MAPK1, MTOR, PTEN, ARC, and SYN1 in 80 patients with major depressive disorder treated according to the Texas Medical Algorithm for 27 months at Hospital Magalhães Lemos, Porto, Portugal. Our results showed that BDNF rs6265, PTEN rs12569998, and SYN1 rs1142636 SNP were associated with treatment-resistant depression (TRD). Additionally, MAPK1 rs6928 and GSK3B rs6438552 gene polymorphisms were associated with relapse. Moreover, we found a link between the rs6928 MAPK1 polymorphism and time to relapse. These findings suggest that the BDNF, PTEN, and SYN1 genes may play a role in the development of TRD, while MAPK1 and GSK3B may be associated with relapse. GO analysis revealed enrichment in synaptic and trans-synaptic transmission pathways and glutamate receptor activity with TRD-associated genes. Genetic variants in these genes could potentially be incorporated into predictive models of antidepressant response.

Recent advances in biological properties of brown algae-derived compounds for nutraceutical applications.

The increasing demand for nutraceuticals in the circular economy era has driven the research toward studying bioactive compounds from renewable underexploited resources. In this regard, the exploration of brown algae has shown significant growth and maintains a great promise for the future. One possible explanation could be that brown algae are rich sources of nutritional compounds (polyunsaturated fatty acids, fiber, proteins, minerals, and vitamins) and unique metabolic compounds (phlorotannins, fucoxanthin, fucoidan) with promising biological activities that make them good candidates for nutraceutical applications with increased value-added. In this review, a deep description of bioactive compounds from brown algae is presented. In addition, recent advances in biological activities ascribed to these compounds through in vitro and in vivo assays are pointed out. Delivery strategies to overcome some drawbacks related to the direct application of algae-derived compounds (low solubility, thermal instability, bioavailability, unpleasant organoleptic properties) are also reviewed. Finally, current commercial and legal statuses of ingredients from brown algae are presented, considering future therapeutical and market perspectives as nutraceuticals.

Can Luminol Be a Fluorophore?

In this work, we report a new chemiluminescence system using bis-(2,4,6-trichlorophenyl) oxalate (TCPO) with hydrogen peroxide and luminol as fluorophore. The intense chemiluminescence reaction here described was fully investigated and it was determined that this fluorescent system has two strong light emissions at 440 and 490 nm, respectively. This new, user friendly, intense and striking light emission chemiluminescence system can be used as a very usefull tool for the design and construction of fluorescencent chemical sensors.

New Trends in Food Allergens Detection: Toward Biosensing Strategies.

Food allergens are a real threat to sensitized individuals. Although food labeling is crucial to provide information to consumers with food allergies, accidental exposure to allergenic proteins may result from undeclared allergenic substances by means of food adulteration, fraud or uncontrolled cross-contamination. Allergens detection in foodstuffs can be a very hard task, due to their presence usually in trace amounts, together with the natural interference of the matrix. Methods for allergens analysis can be mainly divided in two large groups: the immunological assays and the DNA-based ones. Mass spectrometry has also been used as a confirmatory tool. Recently, biosensors appeared as innovative, sensitive, selective, environmentally friendly, cheaper and fast techniques (especially when automated and/or miniaturized), able to effectively replace the classical methodologies. In this review, we present the advances in the field of food allergens detection toward the biosensing strategies and discuss the challenges and future perspectives of this technology.

Eruca sativa: Benefits as antioxidants source versus risks of already banned pesticides.

Eruca sativa (rocket salad) has been intensely consumed all over the world, insomuch as, this work was undertaken to evaluate the antioxidant status and the environmental contamination (positive and negative nutritional contribution) of leaves and stems from this vegetable. Antioxidant capacity of rocket salad was assessed by mean of optical methods, such as the total phenolic content (TPC), reducing power assay and DPPH radical scavenging activity. The extent of the environmental contamination was reached through the quantification of thirteen organochlorine pesticides (OCP) by using gas chromatography coupled with electron-capture detector (GC-ECD) and compound confirmations employing gas chromatography tandem mass-spectrometry (GC-MS/MS). The OCP residues were extracted by using Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) methodology.The extent of the environmental contamination was reached through the quantification of thirteen OCP by using gas chromatography coupled with electron-capture detector (GC-ECD) and compound confirmations employing GC-MS/MS. The OCP residues were extracted by using Quick, Easy, Cheap, Effective, Rugged and Safe (QuEChERS) methodology. This demonstrated that leaves presented more antioxidant activity than stems, emphasizing that leaves contained six times more polyphenolic compounds than stems. In what concerns the OCP occurrence, the average recoveries obtained at the three levels tested (40, 60 and 80 µg kg(-1)) ranged from 55% to 149% with a relative standard deviation of 11%, (except hexachrorobenzene). Three vegetables samples were collected from supermarkets and analysed following this study. According to data, only one sample achieved 16.21 of ß-hexachlorocyclohexane, confirmed by GC-MS/MS. About OCP quantification, the data indicated that only one sample achieved 16.21 µg kg(-1) of ß-hexachlorocyclohexane, confirmed by GC-MS/MS, being the QuEChERS a good choice for the of OCPs extraction. Furthermore, the leaves consumption guaranty higher levels of antioxidants than stems.

Potential Therapeutic Properties of Olea europaea Leaves from Selected Cultivars Based on Their Mineral and Organic Profiles.

Olive leaves are consumed as an extract or as a whole herbal powder with several potential therapeutic benefits attributed to polyphenols, tocopherol's isomers, and flavonoids, among others. This study assessed the potential variance in the functional features presented by olive leaves from three different Portuguese cultivars-Cobrançosa, Madural, and Verdeal-randomly mix-cultivated in the geographical area of Vale de Salgueiros. Inorganic analysis determined their mineral profiles while an organic analysis measured their total phenolic and flavonoid content, and scanned their phenolic and tocopherol and fatty acid composition. The extracts' biological activity was tested by determining their antimicrobial and antioxidant power as well as their ability to inhibit acetylcholinesterase, butyrylcholinesterase, MAO-A/B, and angiotensin-I-converting enzyme. The inorganic profiles showed them to be an inexpensive source able to address different mineral deficiencies. All cultivars appear to have potential for use as possible antioxidants and future alternative antibiotics against some multidrug-resistant microorganisms, with caution regarding the arsenic content in the Verdeal cultivar. Madural's extract displayed properties to be considered a natural multitarget treatment for Alzheimer's and Parkinson's diseases, depression, and cardiometabolic and dual activity for blood pressure modulation. This work indicates that randomly cultivating different cultivars significantly modifies the leaves' composition while keeping their multifaceted therapeutic value.

From Plants to Psycho-Neurology: Unravelling the Therapeutic Benefits of Bioactive Compounds in Brain Disorders.

The brain's sensitivity to oxidative stress and neuronal cell death requires effective pharmacotherapy approaches. Current pharmacological therapies are frequently ineffective and display negative side effects. Bioactive chemicals found in plants may provide a potential alternative due to their antioxidant and neuroprotective properties and can be used in therapy and the management of a variety of neuropsychiatric, neurodevelopmental, and neurodegenerative illnesses. Several natural products, including vitamin C, Cammelia sinensis polyphenols, Hypericum perforatum, and Crocus sativus have shown promise in lowering oxidative stress and treating symptoms of major depressive disorder (MDD). Similarly, bioactive compounds such as curcumin, luteolin, resveratrol, quercetin, and plants like Acorus gramineus, Rhodiola rosea, and Ginkgo biloba are associated with neuroprotective effects and symptom improvement in neurodevelopmental disorders such as autism spectrum disorder (ASD) and attention deficit/hyperactivity disorder (ADHD). Furthermore, in neurodegenerative diseases, natural compounds from Rhodiola rosea, Morinda lucida, and Glutinous rehmannia provide neurological improvement. Further study in clinical samples is required to thoroughly investigate the therapeutic advantages of these bioactive substances for persons suffering from these illnesses.

Bioactive Compounds of Shrimp Shell Waste from Palaemon serratus and Palaemon varians from Portuguese Coast.

The production and consumption of shrimp species create massive amounts of shrimp bio-waste. In this study, shrimp shell waste from Palaemon serratus and Palaemon varians from the Portuguese coast was characterized. Regarding the antioxidant capacity, the obtained values were between 4.7 and 10.4 mg gallic acid equivalents (GAE)/g dry weight (dw) for Total phenolic content (TPC); 3 and 7 mg ascorbic acid equivalents (AAE)/g dw for Ferric reducing antioxidant power assay (FRAP); 0.4 and 1.2 mg Trolox equivalent (TE)/g dw for 2,2-diphenyl-1-picryl-hydrazyl-hydrate free radical scavenging (DPPH•); 4 and 11 mg TE/g dw for 2,2'-azino-bis (3-ethylbenzothiazoline-6-sulfonic acid) radical scavenging activity (ABTS•+); and 72 and 130 mg TE/g dw for Oxygen radical absorbance capacity (ORAC). For the antimicrobial activity, shrimp shell waste from P. varians formed inhibition zones between 14 and 23 mm. Total carotenoid content values were in the range of 28 and 134 µg/g dw, and according to their HPLC-PAD profile, ß-carotene and astaxanthin contents were between 0.3 and 7.6 µg/g dw and 1.1 and 26.1 µg/g dw, respectively. These studies are critical to recognizing the potential added value of shrimp shell waste as possible colorants and preservatives with antioxidant protection capacity to be used in the food industry.

Development of an electrochemical DNA-based biosensor for the detection of the cardiovascular pharmacogenetic-altering SNP CYP2C9*3.

Cardiovascular diseases are among the major causes of mortality and morbidity. Warfarin is often prescribed for these disorders, an anticoagulant with inter and intra-dosage variability dose required to achieve the target international normalized ratio. Warfarin presents a narrow therapeutic index, and due to its variability, it can often be associated with the risk of hemorrhage, or in other patients, thromboembolism. Single-nucleotide polymorphisms are included in the causes that contribute to this variability. The Cytochrome P450 (CYP) 2C9*3 genetic polymorphism modifies its enzymatic activity, and hence warfarin's plasmatic concentration. Thus, the need for a selective, rapid, low-cost, and real-time detection device is crucial before prescribing warfarin. In this work, a disposable electrochemical DNA-based biosensor capable of detecting CYP2C9*3 polymorphism was developed. By analyzing genomic databases, two specific 78 base pairs DNA probes; one with the wild-type adenine (Target-A) and another with the cytosine (Target-C) single-nucleotide genetic variation were designed. The biosensor implied the immobilization on screen-printed gold electrodes of a self-assembled monolayer composed by mercaptohexanol and a linear CYP2C9*3 DNA-capture probe. To improve the selectivity and avoid secondary structures a sandwich format of the CYP2C9*3 allele was designed using complementary fluorescein isothiocyanate-labeled signaling DNA probe and enzymatic amplification of the electrochemical signal. Chronoamperometric measurements were performed at a range of 0.015-1.00 nM for both DNA targets achieving limit of detection of 42 p.m. The developed DNA-based biosensor was able to discriminate between the two synthetic target DNA targets, as well as the targeted denatured genomic DNA, extracted from volunteers genotyped as non-variant homozygous (A/A) and heterozygous (A/C) of the CYP2C9*3 polymorphism.

Multi-target neuroprotective effects of herbal medicines for Alzheimer's disease.

ETHNOPHARMACOLOGICAL RELEVANCE: Alzheimer's disease is the most common form of dementia, but its treatment options remain few and ineffective. To find new therapeutic strategies, natural products have gained interest due to their neuroprotective potential, being able to target different pathological hallmarks associated with this disorder. Several plant species are traditionally used due to their empirical neuroprotective effects and it is worth to explore their mechanism of action. AIM OF THE STUDY: This study intended to explore the neuroprotective potential of seven traditional medicinal plants, namely Scutellaria baicalensis, Ginkgo biloba, Hypericum perforatum, Curcuma longa, Lavandula angustifolia, Trigonella foenum-graecum and Rosmarinus officinalis. The safety assessment with reference to pesticides residues was also aimed. MATERIALS AND METHODS: Decoctions prepared from these species were chemically characterized by HPLC-DAD and screened for their ability to scavenge four different free radicals (DPPH•, ABTS•+, O2•‒ and •NO) and to inhibit enzymes related to neurodegeneration (cholinesterases and glycogen synthase kinase-3ß). Cell viability through MTT assay was also evaluated in two different brain cell lines, namely non-tumorigenic D3 human brain endothelial cells (hCMEC/D3) and NSC-34 motor neurons. Furthermore, and using GC, 21 pesticides residues were screened. RESULTS: Regarding chemical composition, chromatographic analysis revealed the presence of several flavonoids, phenolic acids, curcuminoids, phenolic diterpenoids, one alkaloid and one naphthodianthrone in the seven decoctions. All extracts were able to scavenge free radicals and were moderate glycogen synthase kinase-3ß inhibitors; however, they displayed weak to moderate acetylcholinesterase and butyrylcholinesterase inhibition. G. biloba and L. angustifolia decoctions were the less cytotoxic to hCMEC/D3 and NSC-34 cell lines. No pesticides residues were detected. CONCLUSIONS: The results extend the knowledge on the potential use of plant extracts to combat multifactorial disorders, giving new insights into therapeutic avenues for Alzheimer's disease.

Screening of Bioactive Properties in Brown Algae from the Northwest Iberian Peninsula.

Algae are an underexploited source of natural bioactive compounds in Western countries, so an increasing interest in the valorization of these marine organisms has emerged in recent years. In this work, the effect of extracting solvent on the extraction yield, phenolic content, antioxidant capacity, and antimicrobial activity of nine brown macroalgae species (Ascophyllum nodosum, Himanthalia elongata, Undaria pinnatifida, Pelvetia canaliculata, Saccharina latissima, Bifurcaria bifurcata, Laminaria ochroleuca, Sargassum muticum, and Fucus spiralis) was assessed. Total phenolic content (TPC) and the antioxidant properties of extracts by different assays: radical scavenging activity (DPPH-RSA) and ferric reducing antioxidant power (FRAP) were performed. The antimicrobial activity of extracts was studied against six different foodborne microorganisms: Staphylococcus aureus, Staphylococcus epidermidis, Bacillus cereus, Escherichia coli, Salmonella enteritidis, and Pseudomonas aeruginosa. The highest extraction yield was achieved in ethanolic extracts. However, the highest TPC and FRAP values were obtained on the ethyl acetate extracts, especially from A. nodosum. Concerning algal species, the highest TPC and FRAP values were found in A. nodosum, while the highest DPPH-RSA values were achieved in the hexane extracts of B. bifurcata. The antimicrobial activity of algal extracts varied according to the solvent and alga selected, suggesting the species- and solvent-dependent behavior of this property, with B. bifurcata extracts showing the highest results for a wide range of bacteria. Our results provide insight on the characterization of widespread brown algae in the coasts of the North-Western region of the Iberian Peninsula, reflecting multiple health-enhancing properties which may lead to their exploitation in food, pharmacological, and cosmetic industries.

Macroalgae as a Source of Valuable Antimicrobial Compounds: Extraction and Applications.

In the last few decades, attention on new natural antimicrobial compounds has arisen due to a change in consumer preferences and the increase in the number of resistant microorganisms. Macroalgae play a special role in the pursuit of new active molecules as they have been traditionally consumed and are known for their chemical and nutritional composition and their biological properties, including antimicrobial activity. Among the bioactive molecules of algae, proteins and peptides, polysaccharides, polyphenols, polyunsaturated fatty acids and pigments can be highlighted. However, for the complete obtaining and incorporation of these molecules, it is essential to achieve easy, profitable and sustainable recovery of these compounds. For this purpose, novel liquid-liquid and solid-liquid extraction techniques have been studied, such as supercritical, ultrasound, microwave, enzymatic, high pressure, accelerated solvent and intensity pulsed electric fields extraction techniques. Moreover, different applications have been proposed for these compounds, such as preservatives in the food or cosmetic industries, as antibiotics in the pharmaceutical industry, as antibiofilm, antifouling, coating in active packaging, prebiotics or in nanoparticles. This review presents the main antimicrobial potential of macroalgae, their specific bioactive compounds and novel green extraction technologies to efficiently extract them, with emphasis on the antibacterial and antifungal data and their applications.

Fe3O4@Au nanoparticles-based magnetoplatform for the HMGA maize endogenous gene electrochemical genosensing.

This work addresses a technological advance applied to the construction of a magnetogenoassay with electrochemical transduction for the maize taxon-specific (HMGA gene) detection using gold-coated magnetic nanoparticles as nanosized platform. Superparamagnetic core-shell Fe3O4@Au nanoparticles (10.4 ±â€¯1.7 nm) were used to assemble the genoassay through the covalent immobilization of HMGA DNA probes onto carboxylated self-assembled monolayers at the nanoparticles surface. A hybridization reaction using sandwich format was selected to prevent inefficient hybridization connected with stable secondary DNA structures using also fluorescein isothiocyanate as DNA signaling tag. The labelling of the hybridization reaction with enzymes allowed the chronoamperometric measurement of the peroxidase activity linked to the nanoplatform located on gold surface. Using this electrochemical magnetogenoassay a linear concentration range from 0.5 to 5 nM and a LOD of 90 pM with a RSD <1.2% was calculated. Certified maize was evaluated without further purification after PCR amplification. This work highlights the efficacy of the electrochemical magnetogenoassay for the HMGA detection, showing its potential as alternative procedure for the verification of the compliance of the legislation.

Antibacterial Use of Macroalgae Compounds against Foodborne Pathogens.

The search for food resources is a constant in human history. Nowadays, the search for natural and safe food supplies is of foremost importance. Accordingly, there is a renewed interest in eco-friendly and natural products for substitution of synthetic additives. In addition, microbial contamination of food products during their obtaining and distribution processes is still a sanitary issue, and an important target for the food industry is to avoid food contamination and its related foodborne illnesses. These diseases are fundamentally caused by certain microorganisms listed in this review and classified according to their Gram negative or positive character. Algae have proven to possess high nutritional value and a wide variety of biological properties due to their content in active compounds. Among these capabilities, macroalgae are recognized for having antimicrobial properties. Thus, the present paper revises the actual knowledge of microbial contaminants in the food industry and proposes antimicrobial algal compounds against those pathogenic bacteria responsible for food contamination as valuable molecules for its growth inhibition. The capacity of algae extracts to inhibit some major food pathogen growth was assessed. Moreover, the main applications of these compounds in the food industry were discussed while considering their favorable effects in terms of food safety and quality control.

In situ formation of gold nanoparticles in polymer inclusion membrane: Application as platform in a label-free potentiometric immunosensor for Salmonella typhimurium detection.

Polymeric ion selective electrodes are highly sensitive to changes in zero current ion flow and this offers a route to signal amplification in label-free potentiometric immunosensors. In this work, a label-free potentiometric immunosensor toward Salmonella typhimurium (ST) assembled in a home-made pipette-tip electrode is described. The signal-output amplification was implemented on a gold nanoparticle polymer inclusion membrane (AuNPs-PIM) which was used as sensing platform and for antibody immobilization. Additionally, a marker ion was used to detect the antibody-antigen binding event at the electrode surface. The immunosensor construction was performed in several steps: i) gold salt ions extraction in PVC membrane; ii) AuNPs formation using Na2EDTA as reduction agent; iii) antibody anti-Salmonella conjugation on AuNPs-PIM in pipette-tip electrodes. The potential shift observed in potentiometric measurements was derived simply from the blocking effect in the ionic flux caused by antigen-antibody conjugation, without no extra steps, mimetizing the ion-channel sensors. A detection limit of 6 cells mL-1 was attained. As proof-of-concept, recovery studies were performed in spiked commercial apple juice samples with success. Due to the simplicity of use, the appealing cost of equipment and sensor production and being able to provide a quick analytical response (less than 1 h for a complete assay, including sample preparation for analysis), this scheme represents a good prototype device for the detection of foodborne pathogens like ST or other immune-responsive bacteria.

Direct PCR-free electrochemical biosensing of plant-food derived nucleic acids in genomic DNA extracts. Application to the determination of the key allergen Sola l 7 in tomato seeds.

A novel and disposable electrochemical biosensor for PCR-free and selective detection of Sola l 7, a non-specific lipid transfer protein (nsLTP) found in tomato seeds associated to severe symptoms of tomato-allergic patients, is reported in this work. The methodology involves the formation of DNA/RNA heterohybrids by sandwich hybridization of a specific fragment of the Sola l 7 allergen coding sequence with appropriate RNA probes designed and described for the first time in this work. Labeling was carried out with commercial antibodies specific to the heteroduplexes and secondary antibodies conjugated with HRP onto the surface of magnetic beads. Amperometric transduction was performed upon magnetic capture of the resulting magnetic bioconjugates on screen-printed electrodes using the system H2O2/HQ. A comparison of the sandwich hybridization format with a direct approach as well as between different labeling strategies was performed. The LOD value achieved was 0.2 pM (5 amol in 25 µL). The biosensor was successfully applied to the selective analysis of the targeted Sola l 7 specific region directly in just 100 ng of non-fragmented denatured genomic DNA extracted from tomato seeds.

Study of lipid peroxidation and ascorbic acid protective role in large unilamellar vesicles from a new electrochemical performance.

In this contribution an electrochemical study is described for the first time of lipid peroxidation and the role of antioxidant on lipid protection using large unilamellar vesicles (LUVs). In order to simulate the cell membrane, LUVs composed of 1,2-dioleoyl-sn-glycero-3-phosphocholine (DOPC) were used. A vesicle-modified electrode was constructed by immobilizing DOPC LUVs onto carbon paste electrodes (CPEs). Lipid peroxidation was studied electrochemically by incubating the vesicle-modified electrodes with hydroxyl (HO) radicals generated via the Fenton reaction. Oxidative damage induced by HO was verified by using square wave voltammetry (SWV) and was indirectly measured by the increase of electrochemical peak current to [Fe(CN)6]4- which was used as the electrochemical label. Ascorbic acid (AA) was used as the antioxidant model in order to study its efficacy on free radical scavenging. The decrease of the electrochemical signal confirms the protective key role promoted by AA in the prevention of lipid peroxidation in vesicles. Through microscopy, it was possible to observe morphologic modification on vesicle structures after lipid peroxidation in the presence or absence of AA.

Electrochemical genoassays on gold-coated magnetic nanoparticles to quantify genetically modified organisms (GMOs) in food and feed as GMO percentage.

The integration of nanomaterials in the field of (bio)sensors has allowed developing strategies with improved analytical performance. In this work, ultrasmall core-shell Fe3O4@Au magnetic nanoparticles (MNPs) were used as the platform for the immobilization of event-specific Roundup Ready (RR) soybean and taxon-specific DNA sequences. Firstly, monodisperse Fe3O4 MNPs were synthesized by thermal decomposition and subsequently coated with a gold shell through reduction of Au(III) precursor on the surface of the MNPs in the presence of an organic capping agent. This nanosupport exhibited high colloidal stability, average particle size of 10.2 ±â€¯1.3 nm, and spherical shape. The covalent immobilization of ssDNA probe onto the Au shell of the Fe3O4@Au MNPs was achieved through a self-assembled monolayer (SAM) created from mixtures of alkane thiols (6-mercapto-1-hexanol and mercaptohexanoic acid). The influence of the thiols ratio on the electrochemical performance of the resulting electrochemical genoassays was studied, and remarkably, the best analytical performance was achieved for a pure mercaptohexanoic acid SAM. Two quantification assays were designed; one targeting an RR sequence and a second targeting a reference soybean gene, both with a sandwich format for hybridization, signaling probes labelled with fluorescein isothiocyanate (FITC), enzymatic amplification and chronoamperometric detection at screen-printed carbon electrodes (SPCE). The magnetogenoassays exhibited linear ranges from 0.1 to 10.0 nM and from 0.1 to 5.0 nM with similar detection limits of 0.02 nM and 0.05 nM for the event-specific (RR) and the taxon-specific (lectin) targets, respectively. The usefulness of the approach was demonstrated by its application to detect genetically modified organisms (GMOs) in feed and food.

Potential of Portuguese vine shoot wastes as natural resources of bioactive compounds.

Since annually a high amount of wastes is produced in vine pruning, the aim of this study was to evaluate the potential of vine shoots from two Portuguese grape varieties (Touriga Nacional - TN and Tinta Roriz - TR) to be used as a natural source of phenolic compounds. To reach this goal, three techniques were explored, namely microwave-assisted extraction (MAE), subcritical water extraction (SWE) and conventional extraction (CE). The phenolic composition of the extracts, antioxidant and biological activities were evaluated by spectrophotometry and chromatography. MAE and SWE produced the highest concentrated extracts. TR vine shoot variety had the highest antioxidant activity and total phenolic (32.1±0.9mggallicacidequivalents/g dry sample), as well as flavonoid content (18.7±1.2mgepicatechinequivalents/g dry sample). For the first time, the biological activity of the vine shoot extracts was tested. Results demonstrated that all of them had antimicrobial potential against different bacteria and yeasts, and the ability of inhibiting α-amylase and acetylcholinesterase enzymes, with MAE TR extracts being the most efficient. HPLC analysis enabled the identification of different phenolic compounds, with gallic acid, catechin, myricetin and kaempferol-3-O-rutinoside being the main contributors to the phenolic composition. Portuguese vine shoot wastes could serve as easily accessible source of natural antioxidants for the food or pharmaceutical industries.