Publications

Abstract Soybean is a legume with high technological functionality, commonly used by the food industry as an ingredient in different products. However, soybean is an allergenic food whose undeclared presence in processed foods may represent a public health risk. In this work, it was developed an efficient electrochemical immunosensor, targeting the soybean trypsin inhibitor (Gly m TI) allergen using commercial anti-Gly m TI IgG, aiming at detecting/quantifying minute amounts of soybean in different food formulations. For this purpose, model mixtures of different foods (sausages, cooked-hams, biscuits) were prepared to contain known amounts of soybean protein isolate (100,000-0.1 mg kg(-1)) and submitted to specific thermal treatments (autoclaving, oven-cooking, baking). The electrochemical immunosensor allowed quantifying down to 0.1 mg kg(-1) of soybean in the three food matrices, raw and processed (0.0012 mg of Gly m TI/kg of matrix). Accordingly, the immunosensor is suitable for detecting traces of soybean in raw, processed, and complex foods, thus protecting 99 % of soybean-allergic patients.

Abstract Carbon materials are readily available and are essential in energy storage. One of the routes used to enhance their surface area and activity is the decoration of carbons with semiconductors, such as amorphous TiO2, for application in energy storage devices.

Abstract Lithium-sulfur batteries are a promising alternative to lithium-ion batteries as they can potentially offer significantly increased capacities and energy densities. The ever-increasing global battery market demonstrates that there will be an ongoing demand for cost effective battery electrode materials. Materials derived from waste products can simultaneously address two of the greatest challenges of today, i.e., waste management and the requirement to develop sustainable materials. In this study, we detail the carbonisation of gelatin from blue shark and chitin from prawns, both of which are currently considered as waste biproducts of the seafood industry. The chemical and physical properties of the resulting carbons are compared through a correlation of results from structural characterisation techniques, including electron imaging, X-ray diffraction, Raman spectroscopy and nitrogen gas adsorption. We investigated the application of the resulting carbons as sulfur-hosting electrode materials for use in lithium-sulfur batteries. Through comprehensive electrochemical characterisation, we demonstrate that value added porous carbons, derived from marine waste are promising electrode materials for lithium-sulfur batteries. Both samples demonstrated impressive capacity retention when galvanostatically cycled at a rate of C/5 for 500 cycles. This study highlights the importance of looking towards waste products as sustainable feeds for battery material production.

Abstract A plasmonic nanostructure was constructed as a biorecognition element coupled to an optical sensing platform in sandwich format, targeting the hazelnut Cor a 14 allergen-encoding gene. The analytical performance of the genosensor presented a linear dynamic range between 100 amol L-1 and 1 nmol L-1 , a limit of detection (LOD) < 19.9 amol L-1 , and a sensitivity of 13.4 +/- 0.6 m.. The genosensor was successfully hybridized with hazelnut PCR products, tested with model foods, and further validated by real-time PCR. It reached a LOD <0.001% (10 mg kg(-1) ) of hazelnut in wheat material (corresponding to 1.6 mg kg(-1) of protein) and a sensitivity of 17.2 +/- 0.5 m. for a linear range of 0.001%-1%. Herein, a new genosensing approach is proposed as a highly sensitive and specific alternative tool with potential application in monitoring hazelnut as an allergenic food, protecting the health of sensitized/allergic individuals.

Abstract Waste, in particular, biowaste, can be a valuable sourceof novelcarbon materials. Renewable carbon materials, such as biomass-derivedcarbons, have gained significant attention recently as potential electrodematerials for various electrochemical devices, including batteriesand supercapacitors. The importance of renewable carbon materialsas electrodes can be attributed to their sustainability, low cost,high purity, high surface area, and tailored properties. Fish wasterecovered from the fish processing industry can be used for energyapplications and prioritizing the circular economy principles. Herein,a method is proposed to prepare a high surface area biocarbon fromglycogen extracted from mussel cooking wastewater. The biocarbon materialswere characterized using a Brunauer-Emmett-Teller surfacearea analyzer to determine the specific surface area and pore sizeand by scanning electron microscopy coupled with energy-dispersiveX-ray analysis, Raman analysis, attenuated total reflectance Fouriertransform infrared spectroscopy, X-ray diffraction, X-ray photoelectronspectroscopy, and transmission electron microscopy. The electrochemicalcharacterization was performed using a three-electrode system, utilizinga choline chloride-based deep eutectic solvent (DES) as an eco-friendlyand sustainable electrolyte. Optimal time and temperature allowedthe preparation of glycogen-based carbon materials, with a specificsurface area of 1526 m(2) g(-1), a pore volumeof 0.38 cm(3) g(-1), and an associated specificcapacitance of 657 F g(-1) at a current density of1 A g(-1), at 30 degrees C. The optimal material wasscaled up to a two-electrode supercapacitor using a DES-based solid-stateelectrolyte (SSE@DES). This prototype delivered a maximum capacitanceof 703 F g(-1) at a 1 A g(-1) of currentdensity, showing 75% capacitance retention over 1000 cycles, deliveringthe highest energy density of 0.335 W h kg(-1) andpower density of 1341 W kg(-1). Marine waste can bea sustainable source for producing nanoporous carbon materials tobe incorporated as electrode materials in energy storage devices.

Abstract Many theoretical and experimental studies have been focused on the physicochemical properties of dense ionic fluids such as ionic liquids (ILs). However, less attention has been given to interfacial properties involving deep eutectic solvents (DES). The impact of the DES composition, hydrogen bond donor (HBD) structure, temperature, and electrode nature material on the DES-electrode vertical interactions remain vague. The lack of knowledge imposes significant constraints in proposing a suitable Electrical Double Layer model (EDL) to describe the DES at electrified interfaces. Measuring differential capacitance-potential curves is a strategy to assess the EDL structure and understand how ions interact with the electrode surface, which knowledge is fundamental to designing and optimizing electrochemical systems for various applications (e.g., energy storage devices). Accordingly, a set of choline chloride-based DESs was assessed containing distinct HBD at their eutectic composition (the poly-alcohol's 1,2-ethanediol, 1,2-propylene glycol, 1,3-propylene glycol, and the amide urea) against glassy carbon (GC), gold (Au), and the platinum (Pt) electrode at different temperatures. The differential capacitance-potential curves were found to vary significantly in shape in the three different electrode surfaces studied, ranging from camel shape (Au electrode), U-shape (GC), and asymmetric bell shape (polycrystalline Pt). The carboxylic malonic and oxalic acids were also assessed for a proper comparison to understand better the role of the HBD's functional group in shaping the electrode-electrolyte structure against the trend found with diol isomers. A suitable EDL model must inevitably accommodate interfacial properties assessed at the capacitive region, namely the influence of the surface chemistry, potential dependence, DES structure molecules, and temperature in shaping the electrified interfacial anatomy.

Abstract Over the past decade, molecular imprinting (MI) technologyhasmade tremendous progress, and the advancements in nanotechnology havebeen the major driving force behind the improvement of MI technology.The preparation of nanoscale imprinted materials, i.e., molecularlyimprinted polymer nanoparticles (MIP NPs, also commonly called nanoMIPs),opened new horizons in terms of practical applications, includingin the field of sensors. Currently, hydrogels are very promising forapplications in bioanalytical assays and sensors due to their highbiocompatibility and possibility to tune chemical composition, size(microgels, nanogels, etc.), and format (nanostructures, MIP film,fibers, etc.) to prepare optimized analyte-responsive imprinted materials.This review aims to highlight the recent progress on the use of hydrogelMIP NPs for biosensing purposes over the past decade, mainly focusingon their incorporation on sensing devices for detection of a fundamentalclass of biomolecules, the peptides and proteins. The review beginsby directing its focus on the ability of MIPs to replace biologicalantibodies in (bio)analytical assays and highlight their great potentialto face the current demands of chemical sensing in several fields,such as disease diagnosis, food safety, environmental monitoring,among others. After that, we address the general advantages of nanosizedMIPs over macro/micro-MIP materials, such as higher affinity towardtarget analytes and improved binding kinetics. Then, we provide ageneral overview on hydrogel properties and their great advantagesfor applications in the field of Sensors, followed by a brief descriptionon current popular routes for synthesis of imprinted hydrogel nanospherestargeting large biomolecules, namely precipitation polymerizationand solid-phase synthesis, along with fruitful combination with epitopeimprinting as reliable approaches for developing optimized protein-imprintedmaterials. In the second part of the review, we have provided thestate of the art on the application of MIP nanogels for screeningmacromolecules with sensors having different transduction modes (optical,electrochemical, thermal, etc.) and design formats for single use,reusable, continuous monitoring, and even multiple analyte detectionin specialized laboratories or in situ using mobiletechnology. Finally, we explore aspects about the development of thistechnology and its applications and discuss areas of future growth.

Abstract The scientific community's interest in developing sustainable carbon materials from biomass waste is increasing steadily, responding to the need to reduce dependence on fossil fuels. Every day, different biomass sources are suggested for obtaining porous carbon materials with characteristics for application in different areas. Porous carbon materials with a high specific surface area are a subject of interest for application in energy storage devices. This work reports the use of blue shark chondroitin sulfate and gelatine as precursors for developing porous carbon materials for energy storage devices. Commercial chondroitin sulfate was used for comparison. The porous carbons obtained in this study underwent various characterization techniques to assess their properties. A BET surface area analyzer measured the specific surface area and pore size. Additionally, scanning electron microscopy (SEM) coupled with energy dispersive X-ray analysis (EDX), a high resolution-scanning transmission electron microscope (HR-STEM), Raman spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS) were employed to examine the morphology, composition, and structure of the carbons. A modified glassy carbon (GC) electrode was used as the working electrode for the electrochemical characterization. Cyclic voltammetry and galvanostatic charge/discharge techniques were employed with ethaline, an environmentally friendly and sustainable electrolyte based on choline chloride, to assess the electrochemical performance. Furthermore, the most promising samples were subjected to ball-milling to investigate the impact of this process on surface area and capacitance. Blue shark chondroitin sulfate-based carbon presented a specific surface area of 135.2 m(2) g(-1), compared to 76.11 m(2) g(-1) of commercial chondroitin sulfate, both carbonized for 1 h at 1000 & DEG;C. Blue shark gelatine presented a specific surface area of 30.32 m(2) g(-1). The associated specific capacitance of these three samples is 40 F g(-1), 25 F g(-1), and 7 F g(-1). Ball-milling on these samples increased the specific surface area and capacitance of the three studied samples with different optimal milling times. This study presents the novel utilization of carbon materials derived from blue shark (with and without ball-milling) through a one-step carbonization process. These carbon materials were combined with an environmentally friendly DES electrolyte. The aim was to explore their potential application in energy storage devices, representing the first instance of employing blue shark-based carbon materials in this manner.

Abstract Carbon materials derived from marine waste have been drawing attention for supercapacitor applications. In this work, chitins from squid and prawn marine wastes were used as carbon precursors for further application as electrodes for energy storage devices. Chitins were obtained through a deproteinization method based on enzymatic hydrolysis as an alternative to chemical hydrolysis as commonly presented in the literature. The obtained porous carbons were characterized using a BET surface area analyzer to determine the specific surface area and pore size, as well as scanning electron microscopy (SEM) with energy dispersive X-ray analysis (EDX), transmission electron microscopy (TEM), Raman spectroscopy, attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS), to characterize their morphology, composition, and structure. The electrochemical characterization was performed using a glassy carbon (GC) electrode modified with marine waste-based porous carbons as the working electrode through cyclic voltammetry and galvanostatic charge/discharge using ethaline, a choline chloride-based deep eutectic solvent (DES), as an eco-friendly and sustainable electrolyte. Squid and prawn chitin-based carbons presented a surface area of 149.3 m(2) g(-1) and 85.0 m(2) g(-1), pore volume of 0.053 cm(3) g(-1) and 0.029 cm(3) g(-1), and an associated specific capacitance of 20 and 15 F g(-1) at 1 A g(-1), respectively. Preliminary studies were performed to understand the effect of -OH groups on the chitin-based carbon surface with DES as an electrolyte, as well as the effect of aqueous electrolytes (1 mol L-1 sulphuric acid (H2SO4) and 1 mol L-1 potassium hydroxide (KOH)) on the capacitance and retention of the half-cell set up. It is provided, for the first time, the use of chitin-based carbon materials obtained through a one-step carbonization process combined with an eco-friendly DES electrolyte for potential application in energy storage devices.

Abstract A suitable dispersion of carbon materials (e.g., carbon nanotubes (CNTs)) in an appropriate dispersant media, is a prerequisite for many technological applications (e.g., additive purposes, functionalization, mechanical reinforced materials for electrolytes and electrodes for energy storage applications, etc.). Deep eutectic solvents (DES) have been considered as a promising "green" alternative, providing a versatile replacement to volatile organic solvents due to their unique physical-chemical properties, being recognized as low-volatility fluids with great dispersant ability. The present work aims to contribute to appraise the effect of the presence of MWCNTs and Ag-functionalized MWCNTs on the physicochemical properties (viscosity, density, conductivity, surface tension and refractive index) of glyceline (choline chloride and glycerol, 1:2), a Type III DES. To benefit from possible synergetic effects, AgMWCNTs were prepared through pulse reverse electrodeposition of Ag nanoparticles into MWCNTs. Pristine MWCNTs were used as reference material and water as reference dispersant media for comparison purposes. The effect of temperature (20 to 60 degrees C) and concentration on the physicochemical properties of the carbon dispersions (0.2-1.0 mg cm(-3)) were assessed. In all assessed physicochemical properties, AgMWCNTs outperformed pristine MWCNTs dispersions. A paradoxical effect was found in the viscosity trend in glyceline media, in which a marked decrease in the viscosity was found for the MWCNTs and AgMWCNTs materials at lower temperatures. All physicochemical parameters were statistically analyzed using a two-way analysis of variance (ANOVA), at a 5% level of significance.