Two-dimensional (2D) nanomaterials (e.g., graphene) have attracted growing attention in the (bio)sensing area and, in particular, for biomedical applications because of their unique mechanical and physicochemical properties, such as their high thermal and electrical conductivity, biocompatibility, and large surface area. Graphene (G) and its derivatives represent the most common 2D nanomaterials applied to electrochemical (bio)sensors for healthcare applications. This review will pay particular attention to other 2D nanomaterials, such as transition metal dichalcogenides (TMDs), metal-organic frameworks (MOFs), covalent organic frameworks (COFs), and MXenes, applied to the electrochemical biomedical (bio)sensing area, considering the literature of the last five years (2018-2022). An overview of 2D nanostructures focusing on the synthetic approach, the integration with electrodic materials, including other nanomaterials, and with different biorecognition elements such as antibodies, nucleic acids, enzymes, and aptamers, will be provided. Next, significant examples of applications in the clinical field will be reported and discussed together with the role of nanomaterials, the type of (bio)sensor, and the adopted electrochemical technique. Finally, challenges related to future developments of these nanomaterials to design portable sensing systems will be shortly discussed.

A simple and selective method for the determination of caffeine (CAF) and theophylline (THEO) has been developed for a glassy carbon electrode (GCE) modified with a composite including carbon dots (CDs) and chitosan (CS). To our knowledge, there are no previous studies that analyze a CDs-modified GCE for the presence of CAF and THEO. The electrochemical behavior of a GCE modified with a CDs-CS composite was studied in acidic medium by cyclic voltammetry (CV) and differential pulse voltammetry (DPV). Considering the sensor analytical parameters, the same linear concentrations range was found for CAF and THEO ranging from 1 10?5 to 5 10?3 mol L?1 with the same detection limit (LOD) of 1 10?6 mol L?1. The reproducibility and repeatability data were satisfactory in terms of RSD%. Moreover, the storage stability was evaluated, evidencing good results whatever the experimental conditions used. The developed sensor was applied for the simultaneous determination of CAF and THEO in tea and drug, and results were compared with those obtained with HPLC-ESI-MS in SIR mode as an independent method optimized on purpose. The electrochemical sensor presents the undoubled advantages in terms of cheapness, portability, and ease of use, since it does not require skilled personnel.

Electrochemical biosensors are known as analytical tools, guaranteeing rapid and on-site results in medical diagnostics, food safety, environmental protection, and life sciences research. Current research focuses on developing sensors for specific targets and addresses challenges to be solved before their commercialization. These challenges typically include the lowering of the limit of detection, the widening of the linear concentration range, the analysis of real samples in a real environment and the comparison with a standard validation method. Nowadays, functional nanomaterials are designed and applied in electrochemical biosensing to support all these challenges. This review will address the integration of functional nanomaterials in the development of electrochemical biosensors for the rapid diagnosis of viral infections, such as COVID-19, middle east respiratory syndrome (MERS), influenza, hepatitis, human immunodeficiency virus (HIV), and dengue, among others. The role and relevance of the nanomaterial, the type of biosensor, and the electrochemical technique adopted will be discussed. Finally, the critical issues in applying laboratory research to the analysis of real samples, future perspectives, and commercialization aspects of electrochemical biosensors for virus detection will be analyzed.

BACKGROUND: Brewer's spent grain (BSG) is one of the main by-products of beer industry, little used because of its high moisture making it difficult to transport and store. Mainly used as animal feed and for energy production, the agro-industrial waste have recently attracted attention as source of bioactive compounds, with potential applications in many sectors as food, nutraceutical, pharmaceutical, cosmetic, food packaging. The present work focuses on BSG as potential source of valuable small-size bioactive compounds. METHODS: Laboratory-made BSG was obtained by using four base malts for mashing. After drying, BSG was eco-friendly extracted with water and the extracts analyzed by untargeted ElectroSpray Ionization (ESI)-Mass Spectrometry (MS)/Mass Spectrometry (MS) (ESI-MS/MS) infusion experiments and by targeted High Performance Liquid Chromatography-PhotoDiodeArray-ElectroSpray Ionization-Mass Spectrometry (HPLC-PDA-ESI-MS) in Selected Ion Recording (SIR) mode analysis, to investigate the metabolic profile, the phenolic profile, the individual phenolic content, and tryptophan content. Aqueous extracts of malts and wort samples were also analyzed for a comparison. Data were statistically analyzed by ANOVA test. An explorative analysis based on Principal Component Analysis (PCA) was also carried out on malts, wort and threshes, in order to study correlation among samples and between samples and variables. RESULTS: The untargeted ESI-MS/MS infusion experiments provided the mass spectral fingerprint of BSG, evidencing amino acids (?-aminobutyric acid, proline, valine, threonine, leucine/isoleucine, lysine, histidine, phenylalanine and arginine) and organic and inorganic acids (pyruvic, lactic, phosphoric, valerianic, malonic, 2-furoic, malic, citric and gluconic acids), besides sugars. ?-Aminobutyric acid and lactic acid resulted predominant among the others. The targeted HPLC-PDA-ESI-MS in SIR mode analysis provided the phenolic profile of the polar fraction of BSG, evidenced tryptophan as the main residual metabolite in BSG (62.33-75.35 ?g/g dry BSG), and catechin (1.13-4.24 ?g/g dry BSG) as the representative phenolic antioxidant of not pre-treated BSG samples. The chemometric analysis of the individual compounds content in BSG, malt and wort evidenced similarities and differences among the samples. CONCLUSIONS: As main goal, the phytochemical characterization of BSG from base malts highlighted BSG as a potential source of small biomolecules, as tryptophan and catechin, besides ?-aminobutyric acid and lactic acid, opening to new perspectives of application for BSG. Strategies for their recovery are a future challenge. Moreover, ESI-MS/MS analysis was confirmed as a powerful tool for fast characterization of complex matrix. Last, results obtained by chemometric elaboration of data demonstrated the possibility to monitor a small number of molecules to ensure the quality of a final product.

Food allergy has been indicated as the most frequent adverse reaction to food ingredients over the past few years. Since the only way to avoid the occurrence of allergic phenomena is to eliminate allergenic foods, it is essential to have complete and accurate information on the components of foodstuff. In this framework, it is mandatory and crucial to provide fast, cost-effective, affordable, and reliable analysis methods for the screening of specific allergen content in food products. This review reports the research advancements concerning food allergen detection, involving electrochemical biosensors. It focuses on the sensing strategies evidencing different types of recognition elements such as antibodies, nucleic acids, and cells, among others, the nanomaterial role, the several electrochemical techniques involved and last, but not least, the ad hoc electrodic surface modification approaches. Moreover, a selection of the most recent electrochemical sensors for allergen detection are reported and critically analyzed in terms of the sensors' analytical performances. Finally, advantages, limitations, and potentialities for practical applications of electrochemical biosensors for allergens are discussed.

Current trends for the protection and safeguarding of Cultural Heritage (CH) support cautious and continuous documentation and monitoring of monuments as well as their surroundings with the aim to identify the origin of any alteration and make informed decisions before applying any mitigation action. To that end, a methodological approach and the related guidelines for predictive and cost-effective monitoring of the alterations observed on a CH-built asset are being proposed. This methodology considers the characteristic of the monument and its surroundings, with a thorough risk analysis, in a holistic approach which spans different historical eras, materials and environments. The methodology was based on specific test-beds within theHERACLES(H2020-DRS-2015, GA700395) project, focusing on Climatic Change (CC) related events. The test-beds presented visual damages affected by CC that can be generalized to many other CH assets all over Europe. The concept follows protocol creation, defined in the form of checklists, aiming to estimate and classify the assessed alteration, in correlation with the factors affecting them. The overall goal is to incorporate the proposed methodology into everyday practice which will enable the creation of monitoring reports according to the needs and specificity of each monument/structure/material, supporting the total management cycle, ranging from the initial evaluation of the condition of the monument to specific mitigation actions. This methodology supported by scientific data enables stakeholders or CH managers to prioritize mitigation actions based on informed decisions.

Antioxidants play a central role in the development and production of food, cosmetics, and pharmaceuticals, to reduce oxidative processes in the human body. Among them, phenolic antioxidants are considered even more efficient than other antioxidants. They are divided into natural and synthetic. Natural antioxidants are generally found in plants and their synthetic counterparts are generally added as preventing agents of lipid oxidation during the processing and storage of fats, oils, and lipid-containing foods: All of them can exhibit different effects on human health, which are not always beneficial. Because of their relevant bioactivity and importance in several sectors, such as agro-food, pharmaceutical, and cosmetic, it is crucial to have fast and reliable analysis Rmethods available. In this review, different examples of gold nanomaterial-based electrochemical (bio)sensors used for the rapid and selective detection of phenolic compounds are analyzed and discussed, evidencing the important role of gold nanomaterials, and including systems with or without specific recognition elements, such as biomolecules, enzymes, etc. Moreover, a selection of gold nanomaterials involved in the designing of this kind of (bio)sensor is reported and critically analyzed. Finally, advantages, limitations, and potentialities for practical applications of gold nanomaterial- based electrochemical (bio)sensors for detecting phenolic antioxidants are discussed.

Chitosan is a biopolymer derived from chitin. It is a non-toxic, biocompatible, bioactive, and biodegradable polymer. Due to its properties, chitosan has found applications in several and different fields such as agriculture, food industry, medicine, paper fabrication, textile industry, and water treatment. In addition to these properties, chitosan has a good film-forming ability which allows it to be widely used for the development of sensors and biosensors. This review is focused on the use of chitosan for the formulation of electrochemical chemosensors. It also aims to provide an overview of the advantages of using chitosan as an immobilization platform for biomolecules by highlighting its applications in electrochemical biosensors. Finally, applications of chitosan-based electrochemical chemosensors and biosensors in food safety are illustrated.

Safety and quality are key issues for the food industry. Consequently, there is growing demand to preserve the food chain and products against substances toxic, harmful to human health, such as contaminants, allergens, toxins, or pathogens. For this reason, it is mandatory to develop highly sensitive, reliable, rapid, and cost-effective sensing systems/devices, such as electrochem-ical sensors/biosensors. Generally, conventional techniques are limited by long analyses, expen-sive and complex procedures, and skilled personnel. Therefore, developing performant electro-chemical biosensors can significantly support the screening of food chains and products. Here, we report some of the recent developments in this area and analyze the contributions produced by electrochemical biosensors in food screening and their challenges.

Nanomaterials have received increasing attention due to their unique physical and chemical properties such as high surface-to-volume ratio, high electrical conductivity, chemical stability/durability, and high mechanical strength suitable for applications in many fields, such as biotechnology, optics, electronics, and catalysis. In this review, a survey of the application of different nanomaterials and nanocomposites, with the focus on sensing platforms for detection of phenolic antioxidants and serotonin is presented

Recently, nanomaterials have received increasing attention due to their unique physical and chemical properties, which make them of considerable interest for applications in many fields, such as biotechnology, optics, electronics, and catalysis. The development of nanomaterials has proven fundamental for the development of smart electrochemical sensors to be used in dierent application fields such, as biomedical, environmental, and food analysis. In fact, they showed high performances in terms of sensitivity and selectivity. In this report, we present a survey of the application of dierent nanomaterials and nanocomposites with tailored morphological properties as sensing platforms for food analysis. Particular attention has been devoted to the sensors developed with nanomaterials such as carbon-based nanomaterials, metallic nanomaterials, and related nanocomposites. Finally, several examples of sensors for the detection of some analytes present in food and beverages, such as some hydroxycinnamic acids (caeic acid, chlorogenic acid, and rosmarinic acid), caeine (CAF), ascorbic acid (AA), and nitrite are reported and evidenced.

In the frame of the HERACLES (HEritage Resilience Against CLimate Events on Site) project, a set of cultural heritage sites was studied to improve their resilience against climate events. The mediaeval Town Walls of Gubbio, in the centre of Italy, are among these. Over the centuries, several factors including environmental actions and structural and material repairs have produced different criticalities, involving both structure and materials. A severe problem consists in the progressive degradation of the mortars binding the masonry. Since the wall body structure behaves/reacts properly only if the cohesion between mortar and stones is sufficiently large, it follows that mortars degradation represents a quite significant issue that deserves a special attention. The present work focuses on the characterization of the mortars sampled in various parts of the Walls, corresponding to different historical periods, restoration measures and interventions. They were characterized to determine the corresponding mineralogical and chemical compositions along with morphological features and to investigate their mechanical properties. For that purpose, penetrometric and sclerometric tests on site and ex situ laboratory techniques, such as X-ray diffraction, polarized light microscopy, scanning electron microscopy, thermogravimetry and differential thermal analysis, were used to examine the weathering effects on mortars and more generally their degradation state, in order to plan appropriate restoration and repair actions.

The interaction between monuments and their surrounding environment significantly affects their preservation state. For Cultural Heritage (CH) monuments, the risk analysis investigates how a factor (environmental, socioeconomical, etc.) can cause alteration to the value and integrity of the CH asset, manifested in different forms especially in Climate Change crisis events. The understanding and monitoring of the surroundings of a monument in terms of significance, climate and environment, with the aim to clearly identify the origin of any alteration before applying any treatment, is becoming the current concept for the protection and safeguarding of CH. This work identifies a methodological approach and the related guidelines for predictive and cost-effective monitoring of the alterations observed on a CH monument in correlations to its surroundings. Systematic monitoring protocols and conservation-restoration actions for CH are initially discussed in their general context and in accordance with the international as well as national, legislation. Subsequently the specific needs for conservation-restoration (C-R) actions are set. As case study areas, the HERACLES test-beds, namely the Town Walls and Consoli Palace in Gubbio and the Palace of Knossos and the Venetian Sea fortress of Koules in Heraklion, are been discussed. The objective was to design a general methodology that can be part of the regular monitoring for the condition/ preservation state of built CH. It can lead in the classification of damage or decay and therefore help in prioritizing the need for C-R actions. In particular, protocols are defined in the form of checklists, with the aim to estimate and classify the evidenced damage and decay, in correlation with the factors of alteration. The aim is to be incorporated in the HERACLES platform, which will enable the production of reports according to the needs and specificity of each monument/ structure/ material, supporting the total management cycle, ranging from the initial evaluation of the condition of the monument to the specific maintenance and preservation actions. The proposed methodology can be used as a tool for: a) collecting information about a monument and its surrounding environment through an organized and systematic methodology for monitoring its condition, b) correlate the alteration factors to observed alteration and estimate, or even predict, future damage or decay and therefore help in prioritizing intervention for the maintenance and preservation of the CH monument, and c) help in suggesting preventing actions, directed to the monuments surroundings, in order to prevent or mitigate future damage or decay.

The complexity of degradation and decay phenomena on cultural heritage from artefacts to large scale buildings poses a challenge in the choices made by conservators and restorers for the assessment and protection for future generations of our historical legacy. Cultural Heritage assets on exposed areas are particularly sensitive natural hazards, climate changes and anthropic pressure. The European Commission is perceptive of the importance of preserving our heritage, having proposed 2018 has the European Year of Cultural Heritage and through financial support. The HERACLES project [1] received funding to study climate effects on historical sites and how to improve their resilience against climate events. Four test-beds are currently being monitored and among these is the Consoli Palace in Gubbio (Italy). The present work focuses on the characterization of crusts deposited on the stone used for the construction of the Consoli Palace, collected from different areas on the exterior walls of the monument. They were characterized to determine mineralogical and chemical compositions along with morphological analysis. For that purpose, ex-situ laboratory techniques such as X-ray diffraction (XRD), X-ray fluorescence (XRF), optical microscopy (OM), Fourier transform infrared spectroscopy (FTIR), Polarized Light Microscopy (PLM), Scanning Electron Microscopy (SEM), were used to examine the stone weathering and degradation. [1] HERACLES - HEritage Resilience Against CLimate Events on Site. HERACLES project has received funding from the European Union Framework Programme for Research and Innovation HORIZON 2020 under Grant Agreement nº700395.

The in-depth knowledge of material properties and their weathering behavior is an important basis for developing and planning effective and cost-effective preservation actions, considering the aim of the HERACLES project (HEritage Resilience Against CLimate Events on Site, GA 700395). The well-accepted systematic approach to a sustainable CH asset material preservation can be organized into three phases: anamnesis, diagnosis, and therapy. The anamnesis is followed by the diagnosis. Here, the interdisciplinary research of geologists, chemists, architects, engineers, etc. is required. The overall aim of diagnosis is analysis, quantifications, interpretation, and assessment of material deterioration and damage rate, by considering weathering factors, processes and weathering characteristics as well as the material type, the monument/asset characteristics and the time factor. At the same time, optimization of diagnosis procedures is a crucial step. An accurate diagnosis, together with a correct anamnesis, is the basis of preventive preservation measurements, such as cleaning, desalination, surface protection, materials repair, and replacement, etc. The diagnosis methodological approach includes in-situ materials investigation and ex-situ laboratory analysis and it is focused on the different scale of deterioration. Particularly, the in-situ analyses are applied to obtain information on visible deterioration at mesoscale and at the microscale, while the laboratory (ex-situ) analysis provide information at the microscale and at the nanoscale (non-visible deterioration). Sampling campaigns are necessary for the detailed laboratory analysis. The samples are collected from deteriorated materials (stone, mortars, concrete etc.), located in problematic areas, such as those in close contact with the ground or those exposed to weathering factors. Fresh rock samples are also collected from the original building rocks for comparative analysis. The laboratory analyses of the samples can reveal detailed and accurate information about the not visible degradation. It can also confirm or contradict the suppositions and theories from the in-situ investigations (macroscopic investigations). The laboratory (ex-situ) materials characterization is performed by means of different analytical procedures and allows to assess different properties such as composition, micro-texture, porosity properties, etc. Therefore, it is crucial to select the appropriate method, or combination of methods, which ensure the most effective approach to document the materials degradation issues. The overall approach towards a systematic analytical strategy for material characterization and their degradation state within HERACLES project can be outlined as follows: o Definition of material composition through X-ray Diffraction (also micro) (XRD), X-ray Fluorescence (also micro) (XRF), Fourier Transform Infrared Spectroscopy (FTIR), micro Raman, spectrophotometry (UV-Vis-NIR), X-ray photoelectron spectroscopy (XPS), Laser Induced Breakdown (LIBS) o Definition of material structure and texture through Scanning Electron Microscopy (SEM), Atomic Force Microscopy (AFM), micro Raman, Non-Linear microscopy (NL), 4D Surface Volume Topography o Definition of physical properties through Thermogravimetry, Differential Thermal Analysis and Differential Scanning Calorimetry (TG-DTA and DSC) and Ellipsometry. The methodology developed in the HERACLES project aimed at addressing not only the needs of the four HERACLES test-sites (Knossos Palace and Koules Venetian Fortress in Crete, Greece and Consoli Palace and Town Walls, in Gubbio, Italy), but also for showing that it could be of more general application.

Good conservation and restoration practices of cultural heritage assets rely on the knowledge of original materials. In the framework of the HERACLES Project (HERACLES--HEritage Resilience Against CLimate Events on Site, H2020 Grant Agreement 700395), dealing with the effects of climatic actions and natural hazards on built heritage, a set of important heritage sites are currently under study to improve their resilience against climate events. Among these are the medieval Gubbio Town Walls in Italy. The present work focuses on the mortars and binders of this monument and collected samples related to different parts of the Walls, corresponding to various historical periods of construction and interventions. They were characterized to determine their minerochemical composition, thermal behavior, and morphology. For that purpose, ex-situ laboratory techniques, such as X-ray diffraction (XRD), wavelength dispersive X-ray fluorescence (WDXRF), optical microscopy (OM), polarized light microscopy (PLM), scanning electron microscopy (SEM), and simultaneous differential thermal analysis and thermogravimetry (TG-DTA) were used to discern trends in different sampling areas due to construction/reconstruction periods and building techniques.

[object Object]Background: Antioxidant properties have been recently suggested for caffeine that seems showing protective effects against damages caused by oxidative stress. In particular, a HO% scavenging activity has been ascribed to caffeine. Even if the oxidation of caffeine has been widely studied, the antioxidant mechanism is still far to be understood. Methods: The electrochemical behavior of caffeine, theobromine and theophylline was studied in aprotic medium by cyclic voltammetry and electrolysis in UV-vis cell; a computational analysis of the molecular structures based on the Density Functional Theory was performed; the reactivity of all substrates towards lead dioxide, superoxide and galvinoxyl radical was followed by UV-vis spectrophotometry. Results: Results supported the mono-electronic oxidation of the C4]C5 bond for all substrates at high oxidation potentials, the electron-transfer process leading to a radical cation or a neutral radical according to the starting methylxanthine N7-substituted (caffeine and theobromine) or N7-unsubstituted (theophylline), respectively. A different following chemical fate might be predicted for the radical cation or the neutral radical. No interaction was evidenced towards the tested reactive oxygen species. Conclusions: No reactivity via H-atom transfer was evidenced for all studied compounds, suggesting that an antiradical activity should be excluded. Some reactivity only with strong oxidants could be predicted via electron- transfer. The acclaimed HO% scavenging activity should be interpreted in these terms. The study suggested that CAF might be hardly considered an antioxidant. General significance: Beyond the experimental methods used, the discussion of the present results might provide food for thought to the wide audience working on antioxidants.

A simple and selective method for the determination of caffeine also in complex matrix has been developed at a gold electrode modified with gold nanoparticles (AuNPs) synthetized in a chitosan matrix in the presence of oxalic acid. The electrochemical behaviour of caffeine at both gold bare and gold electrode modifiedwith AuNPs with different morphology was carried out in acidic medium by cyclic voltammetry (CV), differential pulse voltammetry (DPV) and electrochemical impedance spectroscopy (EIS). Electrochemical parameters were optimized in order to improve the electrochemical response to caffeine. The most satisfactory result, that means the higher electrochemical improvement, was obtained using a gold electrode modified with AuNPs synthetized in a chitosan matrix in the presence of oxalic acid, in aqueous solution containing HClO4 0.4 mol L-1 as supporting electrolyte. The performance of the sensor was then evaluated in terms of linearity range (2.0 × 10-6-5.0 × 10-2 mol L-1, R = 0.999), operational and storage stability, reproducibility (RSD = 3.7%), limit of detection (LOD = 1.0 × 10-6 mol L-1) and response to a series of interfering compounds as ascorbic acid, citric acid, gallic acid, caffeic acid, ferulic acid, chlorogenic acid, glucose, catechin and epicatechin. The sensor was then successfully applied to determine the caffeine content in commercial beverages and results were compared with those obtained with HPLC-PDA as an independent method and with those declared from manufacturers.

Caffeine is a natural alkaloid exerting many physiological effects, such as stimulation of the central nervous system, diuresis and gastric acid secretion. It is widely distributed in plant products and beverages and its quantification is mainly of pharmaceutical and alimentary concern. In this paper, we describe an electrochemical study based on the modification of a gold electrode (Au) surface by deposition of functionalized gold nanoparticles by Cyclic Voltammetry (CV). The oxidation system is characterized by an anodic peak in the positive-going step and by the absence of any cathodic peak on the reverse scan, indicating that the oxidation is irreversible. At the modified electrode, the voltammetric peak height increases vs. that @ the bare one, depending on the nanoparticles functionalization. The best performances were observed @ Au electrode modified with colloidal gold nanoparticles (AuNPs) stabilized into a chitosan matrix. In order to optimize the influence of different electrolytes on the sensor response, different electrolytic solutions (nitric acid, sulfuric acid, phosphoric acid and hydrochloric acid) were used. The electro-chemical behavior of caffeine was also studied in aprotic medium with the aim to clear up the different mechanisms the oxidative process occurs through in aqueous and in aprotic medium.

A glucose impedimetric biosensor was assembled using a suggested gold microtubes (AuTs) archi-tecture. A platinum (Pt) electrode (diameter 3 mm) was coated by gold microtubes, synthesized viaelectroless deposition within the pores of polycarbonate particle track-etched membranes (PTM). Thisplatform was successfully used to deposit polypyrrole overoxidized film (OpPy) and to verify the pos-sibility of developing a biosensor using OpPy, the characteristics of the H2O2charge transfer reactionwere studied before the enzyme immobilization. This composite material could be suitable in devices asbiosensors based on oxidase enzymes, just because hydrogen peroxide is a side-product of the catalysisand could be directly related to the concentration of the analyte. Finally, a biosensor consisting in a Ptelectrode modified with AuTs, OpPy and glucose oxidase was assembled to determine the glucose.The most important result of this biosensor was the wide linear range of concentration, ranging from1.0 to 100 mM (18-1800 mg dl-1), covering the hypo- and hyperglycemia range, useful in diabetes, withlimit of detection (LOD) of 0.1 mM (1.8 mg dl-1) and limit of quantification (LOQ) 1.0 mM (18 mg dl-1).