Evaluation of reduced graphene oxide-based nanomaterial as dispersive solid phase extraction sorbent for isolation and purification of aflatoxins from poultry feed, combined with UHPLC-MS/MS analysis.

Poultry feed comprises cereals and their by-products and is vulnerable to aflatoxins contamination. This study utilised reduced graphene oxide-titanium dioxide (rGO-TiO2) nanomaterial as a dispersive solid phase extraction (d-SPE) adsorbent to extract, enrich and purify aflatoxins (aflatoxin B1, aflatoxin B2, aflatoxin G1 and aflatoxin G2). The synthesis of rGO-TiO2 nanomaterials through hydrothermal process and characterisation by transmission electron microscopy, scanning electron microscopy, Brunauer-Emmett-Teller (BET) and X-ray diffraction reveals that the nanomaterials have a single-layer structure embedded with TiO2 nanoparticles. The matrix-spiked technique was employed for the extraction process, optimisation of d-SPE, and analytical method validation. The most appropriate extraction solvent was acetonitrile/water/formic acid (79/20/1, v/v/v), with 30 min of extraction time assisted by ultra-sonication. The optimised d-SPE parameters were: 50 mg of rGO-TiO2 as sorbent amount, 2% methanol as the sample loading solvent, 30 min as adsorption time, and absolute ethanol as the washing reagent. The d-SPE method exhibited good desorption efficiency with 3 mL of acetonitrile/formic acid (99/1, v/v) and 20 min desorption time. After validation, the UHPLC-MS/MS analytical method has an acceptable range of specificity, linearity (R2 ≥ 0.999), sensitivity (LOQ 0.04-0.1 µg kg-1), recoveries (74-105% at three matrix-spiked levels) and precision (RSD 1.5-9.6%). Poultry feed samples (n = 12) were pretreated by this method to extract, enrich and analyse aflatoxins, which were detected in all poultry feed samples. The contamination levels were within the permissible limits.

Unveiling the Effects of Carbon-Based Nanomaterials on Crop Growth: From Benefits to Detriments.

To systematically assess the impact of typical CNMs on the growth effects of cereal crops, we conducted a meta-analysis of 48 independent studies worldwide. The pooled results showed that shoot weight (13.39%) and antioxidant metabolite content (SOD: 106.32%, POD: 32.29%, CAT: 22.63%) of cereal crops exposed to the presence of CNMs were significantly increased, but phytohormones secretion (17.84%) was inhibited. The results of subgroup analysis showed that there were differences in the results of different CNM types with the same exposure concentration on growth effects. Short-term exposure adversely affected the root and photosynthetic capacity of the crop, but prolonged exposure instead showed a promoting effect. Multiple linear regression analysis showed that the concentration of CNMs and cereal variety variables were significantly associated with changes in multiple growth effect values. This work could offer references and fresh perspectives for investigating how nanoparticles and crops interact.

Managing Nanomaterials in the Workplace by Using the Control Banding Approach.

Nanomaterials offer new technical and commercial opportunities. However, they may also pose risks to consumers and the environment and raise concerns about occupational health and safety. An overview of the standardization in the area of nanomaterials is presented. Focus is given to the standard ISO/TS 12901-2:2014, which describes the use of a control banding approach for controlling the risks associated with occupational exposures to nano-objects and their aggregates and agglomerates greater than 100 nm. The article also presents a case study on a textile finishing company that implements two chemical finishes containing nanomaterials. A risk analysis was conducted to assess the hazards associated with workers handling nanomaterials. Control banding was applied, and measures such as appropriate ventilation and use of protective equipment are proposed to mitigate risks. In some cases, additional measures, such as a closed booth and smoke extractor, are required. The safety data sheets are a primary source of information on how to handle and care for products containing nanomaterials, but the information provided is still limited in terms of the specific hazards and risks posed by nanomaterials.

Analytical methods for assessing antimicrobial activity of nanomaterials in complex media: advances, challenges, and perspectives.

Assessing the antimicrobial activity of engineered nanomaterials (ENMs), especially in realistic scenarios, is of great significance for both basic research and applications. Multiple analytical methods are available for analysis via off-line or on-line measurements. Real-world samples are often complex with inorganic and organic components, which complicates the measurements of microbial viability and/or metabolic activity. This article highlights the recent advances achieved in analytical methods including typical applications and specifics regarding their accuracy, cost, efficiency, and user-friendliness. Methodological drawbacks, technique gaps, and future perspectives are also discussed. This review aims to help researchers select suitable methods for gaining insight into antimicrobial activities of targeted ENMs in artificial and natural complex matrices.

Occupational Exposure to Incidental Nanomaterials in Metal Additive Manufacturing: An Innovative Approach for Risk Management.

The benefits of metal 3D printing seem unquestionable. However, this additive manufacturing technology brings concerns to occupational safety and health professionals, since recent studies show the existence of airborne nanomaterials in these workplaces. This article explores different approaches to manage the risk of exposure to these incidental nanomaterials, on a case study conducted in a Portuguese organization using Selective Laser Melting (SLM) technology. A monitoring campaign was performed using a condensation particle counter, a canning mobility particle sizer and air sampling for later scanning electron microscopy and energy dispersive X-ray analysis, proving the emission of nano-scale particles and providing insights on number particle concentration, size, shape and chemical composition of airborne matter. Additionally, Control Banding Nanotool v2.0 and Stoffenmanager Nano v1.0 were applied in this case study as qualitative tools, although designed for engineered nanomaterials. This article highlights the limitations of using these quantitative and qualitative approaches when studying metal 3D Printing workstations. As a result, this article proposes the IN Nanotool, a risk management method for incidental nanomaterials designed to overcome the limitations of other existing approaches and to allow non-experts to manage this risk and act preventively to guarantee the safety and health conditions of exposed workers.

Considerations for bioaccumulation studies in fish with nanomaterials.

Nanomaterials (NMs) pose challenges in performing bioaccumulation studies in fish and in regulatory interpretation of results. Therefore, a clear guidance is needed to obtain reliable, reproducible and comparable results. By analysing all the available literature, we aim in this manuscript to identify the critical aspects that should be addressed in these type of studies. Seventy-eight studies from a total of 67 published articles were identified in which a variety of approaches were used: aqueous exposure (49 studies), dietary exposure (19), and pre-exposed animals for trophic transfer studies (10). The NMs tested included TiO2, Zn, ZnO, Cu, CuO, Ag, Au, CeO2, Fe2O3, Fe3O4, Se, CdS, CdSe/ZnS-QDs, CdTe/ZnS-QDs, graphene, fullerenol and MWCNTs. In general, there is a scarcity of bioaccumulation studies for the different NMs. In particular, studies that use the dietary exposure route are lacking. TiO2 NMs are the most studied for bioaccumulation potential in fish (20%), whereas very few data were available for CuO, FeO and carbon-based NMs. Different information gaps were identified in these studies that hamper overall conclusions to be made on the bioaccumulation potential of NMs. The main critical issues related to NM testing for bioaccumulation include: maintenance of stable exposure concentrations, the influence of feeding regimen on uptake and elimination, the use of appropriate feed spiking methodologies, the potential need for testing different concentrations, and the reporting of bioaccumulation endpoints (BCF/BMF). Each of these issues needs further guidance to allow proper use and reporting of NM bioaccumulation data for regulatory purposes.

[Separation and enrichment of trace aflatoxin B1 in grains by magnetic nanomaterials based on SiO2@Fe3O4].

In this study, a magnetic nanomaterial antibody (Ab)-SiO2@Fe3O4 was synthesized, which was employed to absorb aflatoxin B1 (AFB1) in complicated grain matrices. The Ab-SiO2@Fe3O4 material was then paired with high performance liquid chromatography-tandem mass spectrometry (HPLC-MS/MS) for subsequent accurate detection. The Ab-SiO2@Fe3O4 material has a specific adsorption capacity for AFB1 because of the stable and specific biological binding between antigen and antibody. This process can achieve the identification between the material and food matrix quickly, thereby completing the separation and enrichment process. Then, high sensitivity and high accuracy HPLC-MS/MS were employed for signal readout and actual quantification, which can significantly increase the detection efficiency and enable high-throughput detection of numerous samples. In the pretreatment process, Fe3O4 was first synthesized by microwave-assisted hydrothermal synthesis within 1 h, and Ab-SiO2@Fe3O4 was then produced using the enhanced Stober's approach. This material with high adsorption performance was synthesized under relatively mild conditions and short time. To obtain Ab-SiO2@Fe3O4 materials with uniform particle size, magnetic properties, and dispersibility that met the requirements, synthesis conditions of Ab-SiO2@Fe3O4 and conditions for capturing the AFB1 target were analyzed. The findings demonstrated that the best effect was obtained when the dosage of FeCl3·6H2O was 10.0 mmol, the heating time was 40 min, and 100 µL tetraethoxysilane was employed for SiO2 coating. The AFB1 antibody was then combined with the surface of SiO2@Fe3O4 under several conditions. The findings revealed that the best coupling efficiency of Ab could be obtained when the concentration of 2-morpholinoethanesulfonic acid monohydrate (MES) was 10 mmol/L, pH was 6.5, and the molar ratio of 1-(3-dimethylaminopropyl)-3-ethylcarbodiimide hydrochloride (EDC)∶N-hydroxysuccinimide substances (NHS) was 2∶1. The coupling buffer was then selected as phosphate buffer (PBS) with pH=7.4, and 8 mg Ab-SiO2@Fe3O4 was employed to separate and enrich AFB1 at 37 ℃ for 10 min. In the actual detection, acetonitrile-water-formic acid (85∶10∶5, v/v/v) was employed as the extraction solution. After ultrasonic extraction for 10 min, Ab-SiO2@Fe3O4 was employed to separate and enrich AFB1 in the extract. The supernatant was dried with nitrogen and reconstituted with 1-mL acetonitrile. The solution was then filtered through a 0.22 µm filter and detected using HPLC-MS/MS, thereby realizing the quick and quantitative detection of AFB1. AFB1 had an excellent linear relationship in the range of 2-50 µg/L under the optimal analytical conditions, and the correlation coefficient was less than 0.99. The LOD was 0.04 µg/kg, and the LOQ was 0.13 µg/kg. The spiked recoveries of AFB1 in three grain matrices ranged from 76.21% to 92.85% with RSD≤5.29% at four different spiked levels. The approach was applied to the determination and analysis of AFB1 in 30 real grain samples of rice, corn, and wheat. The findings demonstrated that AFB1 was detected in one wheat sample and two corn samples, and its content was 0.38, 0.13, and 0.47 µg/kg, respectively, and no toxins were found in other samples. The approach combined Ab-SiO2@Fe3O4 magnetic nanomaterials with HPLC-MS/MS, which could obtain high-efficiency separation and enrichment of AFB1. Furthermore, the low-cost Ab-SiO2@Fe3O4 could be stored for more than a week and complete the pretreatment process within 30 min. This effective pretreatment process combined with HPLC-MS/MS could realize the analysis of several samples within a short time, and had a promising application prospect in the detection of AFB1 in grains.

A novel porphyrin-based conjugated microporous nanomaterial for solid-phase microextraction of phthalate esters residues in children's food.

A novel porphyrin-based conjugated microporous polymer (PCMP) with microporous structure and nitrogen-rich pyrrole building blocks was synthesized. The PCMP was used as a coating material to prepare solid-phase microextraction (SPME) fibers by sol-gel technique. Due to the toxicity of the phthalate esters (PAEs) and the necessity for their sensitive determinations in some food samples, the SPME fiber was investigated for the extraction of eleven PAEs from six different children's milk beverages prior to their detection by gas chromatography-mass spectrometry. Under the optimal conditions, the linear response range for the PAEs was in the range from 0.03 to 200 µg L-1 and the limits of detection (S/N = 3) for the analytes were 0.01-3.00 µg L-1. The method recoveries for the PAEs were between 80% and 120%, with the relative standard deviations varying from 1.3% to 9.8%. The method was successfully applied for the determination of PAEs in children's milk beverages.

Solid-phase extraction techniques based on nanomaterials for mycotoxin analysis: An overview for food and agricultural products.

Mycotoxin contamination is a globally concerned problem for food and agricultural products since it may directly or indirectly induce severe threats to human health. Sensitive and selective screening is an efficient strategy to prevent or reduce human and animal exposure to mycotoxins. However, enormous challenges exist in the determination of mycotoxins, arising from complex sample matrices, trace-level analytes, and the co-occurrence of diverse mycotoxins. Appropriate sample preparation is essential to isolate, purify, and enrich mycotoxins from complicated matrices, thus decreasing sample matrix effects and lowering detection limits. With the cross-disciplinary development, new solid-phase extraction strategies have been exploited and integrated with nanotechnology to meet the challenges of mycotoxin analysis. This review summarizes the advance and progress of solid-phase extraction techniques as the methodological solutions for mycotoxin analysis. Emphases are paid on nanomaterials fabricated as trapping media of solid-phase extraction techniques, including carbonaceous nanoparticles, metal/metal oxide-based nanoparticles, and nanoporous materials. Advantages and limitations are discussed, along with the potential prospects.

Exposure assessment of nanotitanium oxide powder handling using real-time size-selective particle number concentration measurements and X-ray fluorescence spectrometry -The possibility of exposure to nonagglomerated nanomaterials during the handling of nanomaterial fine powders.

In this study, airborne particles were collected using filters, and the particle number concentrations were measured in two nanotitanium dioxide (nanoTiO2)-manufacturing plants. Real-time particle size measurements were performed using both optical and scanning mobility particle sizer and X-ray fluorescence spectrometry (XRF). The respirable particles collected using filters were used to analyze Ti concentrations in the workplace air of two factories engaged in nanoTiO2 powder bagging processes. The XRF analysis revealed sufficient sensitivity to measure 0.03 mg/m3, which is 1/10 the concentration of the recommended occupational exposure limit of nanoTiO2 in both stationary sampling and personal exposure sampling settings. In a factory where outside air was directly introduced, micron-sized aggregated particles were generated because of factory operations; however, nanosized and submicron-sized particles were not observed owing to high background concentrations of incidental nanoparticles. Alternatively, in another factory where particles from the outside air were removed using a high-efficiency particulate air filter, work-related nanoparticles were released. The findings of this study suggest that in nanoparticle powder handling processes, a nanoparticle exposure risk exists in the form of nonagglomerated state in nanoparticle powder handling processes.

Inorganic Nanomaterial for Biomedical Imaging of Brain Diseases.

In the past few decades, brain diseases have taken a heavy toll on human health and social systems. Magnetic resonance imaging (MRI), photoacoustic imaging (PA), computed tomography (CT), and other imaging modes play important roles in disease prevention and treatment. However, the disadvantages of traditional imaging mode, such as long imaging time and large noise, limit the effective diagnosis of diseases, and reduce the precision treatment of diseases. The ever-growing applications of inorganic nanomaterials in biomedicine provide an exciting way to develop novel imaging systems. Moreover, these nanomaterials with special physicochemical characteristics can be modified by surface modification or combined with functional materials to improve targeting in different diseases of the brain to achieve accurate imaging of disease regions. This article reviews the potential applications of different types of inorganic nanomaterials in vivo imaging and in vitro detection of different brain disease models in recent years. In addition, the future trends, opportunities, and disadvantages of inorganic nanomaterials in the application of brain diseases are also discussed. Additionally, recommendations for improving the sensitivity and accuracy of inorganic nanomaterials in screening/diagnosis of brain diseases.

Glycan Nanostructures of Human Coronaviruses.

Human coronaviruses present a substantial global disease burden, causing damage to populations' health, economy, and social well-being. Glycans are one of the main structural components of all microbes and organismic structures, including viruses-playing multiple essential roles in virus infection and immunity. Studying and understanding virus glycans at the nanoscale provide new insights into the diagnosis and treatment of viruses. Glycan nanostructures are considered potential targets for molecular diagnosis, antiviral therapeutics, and the development of vaccines. This review article describes glycan nanostructures (eg, glycoproteins and glycolipids) that exist in cells, subcellular structures, and microbes. We detail the structure, characterization, synthesis, and functions of virus glycans. Furthermore, we describe the glycan nanostructures of different human coronaviruses, such as human coronavirus 229E (HCoV-229E), human coronavirus OC43 (HCoV-OC43), severe acute respiratory syndrome-associated coronavirus (SARS-CoV), human coronavirus NL63 (HCoV-NL63), human coronavirus HKU1 (HCoV-HKU1), the Middle East respiratory syndrome-associated coronavirus (MERS-CoV), and how glycan nanotechnology can be useful to prevent and combat human coronaviruses infections, along with possibilities that are not yet explored.

Biological evaluation of Safrole oil and Safrole oil Nanoemulgel as antioxidant, antidiabetic, antibacterial, antifungal and anticancer.

BACKGROUND: Safrole is a natural compound extracted from various plants, and has shown various biological activities. The current study aimed to investigate the antioxidant, antidiabetic, antimicrobial, and anticancer activity of safrole oil and to study the influence of safrole nanoemulgel on these activities. METHODS: The antioxidant and antidiabetic in-vitro assays were conducted using standard biomedical methods. The safrole oil nanoemulgel was developed using a self-emulsifying technique. Then the antimicrobial activity of the safrole oil and safrole nanoemulgel were performed on different microbial species, and cytotoxicity was determined against Hep3B cancer cell lines using the MTS assay. RESULTS: Safrole oil showed moderate antioxidant activity compared with standard Trolox, with IC50 value 50.28 ± 0.44 and 1.55 ± 0.32 µg/ml, respectively. Moreover, it had potent α-amylase inhibitory activity (IC50 11.36 ± 0.67 µg/ml) compared with Acarbose (IC50 value 5.88 ± 0.63). The safrole nanoemulgel had pseudo-plastic behaviour, droplet sizes below 200 nm, a polydispersity index (PDI) below 0.3, and a zeta potential of less than - 30 mV. Safrole oil has potential antimicrobial and anticancer activities, and these activities were improved with safrole nanoemulgel. CONCLUSION: The safrole oil may be applied for the prevention and treatment of oxidative stress, diabetes, different microbial species and cancer, and these activities could be improved by nano-carriers.

The Era of Nanomaterials: A Safe Solution or a Risk for Marine Environmental Pollution?

In recent years, the application of engineered nanomaterials (ENMs) in environmental remediation gained increasing attention. Due to their large surface area and high reactivity, ENMs offer the potential for the efficient removal of pollutants from environmental matrices with better performances compared to conventional techniques. However, their fate and safety upon environmental application, which can be associated with their release into the environment, are largely unknown. It is essential to develop systems that can predict ENM interactions with biological systems, their overall environmental and human health impact. Until now, Life-Cycle Assessment (LCA) tools have been employed to investigate ENMs potential environmental impact, from raw material production, design and to their final disposal. However, LCA studies focused on the environmental impact of the production phase lacking information on their environmental impact deriving from in situ employment. A recently developed eco-design framework aimed to fill this knowledge gap by using ecotoxicological tools that allow the assessment of potential hazards posed by ENMs to natural ecosystems and wildlife. In the present review, we illustrate the development of the eco-design framework and review the application of ecotoxicology as a valuable strategy to develop ecosafe ENMs for environmental remediation. Furthermore, we critically describe the currently available ENMs for marine environment remediation and discuss their pros and cons in safe environmental applications together with the need to balance benefits and risks promoting an environmentally safe nanoremediation (ecosafe) for the future.

Application of DNA sequences in anti-counterfeiting: Current progress and challenges.

Counterfeiting has never been more challenging than during the COVID-19 pandemic as counterfeit test kits and therapeutics have been discovered in the market. Current anti-counterfeiting labels have weaknesses: they can either be duplicated easily, are expensive or ill-suited for the existing complex supply chains. While RFID tags provide for an excellent alternative to current anti-counterfeiting methods, they can prove to be expensive and other routes involving nanomaterials can be difficult to encrypt. A DNA based anticounterfeiting system has significant advantages such as relative ease of synthesis and vast data storage abilities, along with great potential in encryption. Although DNA is equipped with such beneficial properties, major challenges that limit its real-world anti-counterfeiting applications include protection in harsh environments, rapid inexpensive sequence determination, and its attachment to products. This review elaborates the current progress of DNA based anti-counterfeiting systems and identifies technological gaps that need to be filled for its practical application. Progress made on addressing the primary challenges associated with the use of DNA, and potential solutions are discussed.

Characterisation of TiO2-containing pearlescent pigments with regard to the European Union labelling obligation of engineered nanomaterials in food.

A wide range of trendy food colourants and ready-to-eat foods containing pearlescent pigments providing glitter effects is currently on the market. These pearlescent pigments consist of mica (potassium aluminium silicate) platelets generally coated with titanium dioxide and/or iron oxides. All single components are approved food additives in the European Union (EU) (E 555, E 171 and E 172). However, the European Food Safety Authority (EFSA) has stated recently, that pearlescent pigments should be evaluated as new food additives. Food grade titanium dioxide was already shown to contain a considerable fraction of nanoparticles. Thus, the question about 'nano'-labelling of TiO2-containing pearlescent pigments according to the 'Novel Food' and 'Food Information to Consumers' regulations arose. In order to provide data for dealing with these issues, in this study four commercially available products of different food categories containing pearlescent pigments were characterised with focus on the structure, size and chemical composition of these pigments. The measurement methods used were flow particle image analysis (FPIA), static light scattering (SLS) and scanning electron microscopy (SEM) combined with energy-dispersive x-ray spectroscopy (EDX). After isolation from various food matrices, the glitter pigments could be easily identified and differentiated by fast FPIA screening from any remaining organic food matrix particles due to their typical platelet-like shape and transparency. The particle size distribution of the platelets was determined by means of SLS and found to be in the range of 8-167 µm. SEM was identified as the most suitable technique for the analysis of the nano-structured coating. For all constituent metal oxide particles (TiO2 and/or Fe2O3) a median minimum Feret diameter (Fmin) of 29.9-46.8 nm was obtained by quantitative SEM image analysis.

Ozone nanobubble modulates the innate defense system of Nile tilapia (Oreochromis niloticus) against Streptococcus agalactiae.

Ozone nanobubble (NB-O3) is a promising technology for improving dissolved oxygen and reducing bacterial concentration in aquaculture systems. Here, we investigated the effects of NB-O3 on the innate immunity of fish by monitoring the expression levels of nonspecific immune-related genes (IL-1ß, IL-2ß, TNF-α), heat-shock protein genes (HSP70, HSP90-α), and a bacteriolytic enzyme, C-type lysozyme, gene (LYZ) post-treatment with this technology. Following exposure to NB-O3, the different tissues of Nile tilapia (Oreochromis niloticus) were collected over time for quantitative real-time PCR (qPCR) analysis. The expression of all the genes evaluated in the gills, the head kidney, and the spleen of the NB-O3 treated group was significantly up-regulated compared to that in the untreated control group. The expression levels were the highest (approx. 2 to 4-fold) at 15 min and 3 h post-exposure and then decreased from 6 to 24 h. These findings suggested that NB-O3 could switch on the innate immunity genes of Nile tilapia. Thus, we hypothesized that the NB-O3-immune-activated fish would respond more effectively to subsequent bacterial infections, thereby improving survivability compared to that of untreated fish. To test this hypothesis, 3 h post NB-O3 exposed fish and unexposed fish were challenged with a lethal dose of Streptococcus agalactiae. Interestingly, the survival rate of the NB-O3 group was significantly higher than that of the non-treated controls, with a relative percent survival (RPS) of 60-70%. Together, these findings indicate, for the first time, that NB-O3 may trigger the nonspecific defense system of the fish, thereby improving fish survivability during subsequent bacterial infections. This research identified another potential benefit of NB-O3 in aquaculture for preventing infectious bacterial diseases.

Imaging inorganic nanomaterial fate down to the organelle level.

Nanotoxicology remains an important and emerging field since only recent years have seen the improvement of biological models and exposure setups toward real-life scenarios. The appropriate analysis of nanomaterial fate in these conditions also required methodological developments in imaging to become sensitive enough and element specific. In the last 2-4 years, impressive breakthroughs have been achieved using electron microscopy, nanoscale secondary ion mass spectrometry, X-ray fluorescence microscopy, or fluorescent sensors. In this review, basics of the approaches and application examples in the study of nanomaterial fate in biological systems will be described to highlight recent successes in the field.

Multi-instrumental techniques for evaluating butterfly structural colors: A case study on Polyommatus bellargus (Rottemburg, 1775) (Lepidoptera: Lycaenidae: Polyommatinae).

Color is an important communication channel for day-flying butterflies. Chemical (pigmentary) coloration is often supplemented by physical color generated by photonic nanostructures. These nanoarchitectures - which are characteristic for a given species - exhibit wavelength ranges in which light propagation is forbidden. The photonic nanoarchitectures are located in the lumen of the wing scales and are developed individually by each scale during metamorphosis. This self-assembly process is governed by the genes in the nucleus of the scale producing cell. It is crucial to establish well-defined measurement methods for the unambiguous characterization and comparison of colors generated in such a complex manner. Owing to the intricate architecture ordered at multiple levels (from centimeters to tens of nanometers), the precise quantitative determination of butterfly wing coloration is not trivial. In this paper, we present an overview of several optical spectroscopy measurement methods and illustrate techniques for processing the obtained data, using the species Polyommatus bellargus as a test case, the males of which exhibit a variation in their blue structural color that is easily recognizable to the naked eye. The benefits and drawbacks of these optical methods are discussed and compared. Furthermore, the origin of the color differences is explained in relation to differences in the wing scale nanomorphology revealed by electron microscopy. This in turn is tentatively associated with the unusually large genetic drift reported for this species in the literature.

Magnetic nanoparticle-based amplification of microRNA detection in body fluids for early disease diagnosis.

Circulating biomarkers such as microRNAs (miRNAs), short noncoding RNA strands, represent prognostic and diagnostic indicators for a variety of physiological disorders making their detection and quantification an attractive approach for minimally invasive early disease diagnosis. However, highly sensitive and selective detection methods are required given the generally low abundance of miRNAs in body fluids together with the presence of large amounts of other potentially interfering biomolecules. Although a variety of miRNA isolation and detection methods have been established in clinics, they usually require trained personnel and often constitute labor-, time- and cost-intensive approaches. During the last years, nanoparticle-based biosensors have received increasing attention due to their superior detection efficiency even in very low concentration regimes. This is based on their unique physicochemical properties in combination with their high surface area that allows for the immobilization of multiple recognition sites resulting in fast and effective recognition of analytes. Among various materials, magnetic nanoparticles have been identified as useful tools for the separation, concentration, and detection of miRNAs. Here, we review state-of-the-art technology with regard to magnetic particle-based miRNA detection from body fluids, critically discussing challenges and future perspective of such biosensors while comparing their handling, sensitivity as well as selectivity against the established miRNA isolation and detection methods.