Publications

Abstract Over the past few decades, ionic liquids (ILs) have gained attention as electrolytes, although concerns about their environmental persistence and toxicity challenge their status as green solvents. In this framework, choline chloride (ChCl) offers a more sustainable alternative due to its low toxicity, biodegradability, and cost-effectiveness. Although ChCl has a high melting point, its combination with hydrogen bond donor compounds (HBDs) can result in liquid mixtures at much lower temperatures, known as deep eutectic solvents (DESs). This study presents a comparative evaluation of three ChCl-based DESs, glyceline, ethaline, and reline (obtained from mixtures of ChCl and glycerol, ethylene glycol, and urea), with a focus specifically on their potential as electrolyte candidates for supercapacitors. Using differential scanning calorimetry (DSC), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS), and nuclear magnetic resonance (NMR), we assess their thermal, electrochemical, and structural properties. All DESs displayed amorphous behavior and a strong tendency to remain liquid even at very low temperatures. Among them, ethaline showed the most promising electrochemical performance, exhibiting the lowest resistivity and the highest capacity.

Abstract This work aimed to develop a new indirect ELISA for detecting the soybean allergen Gly m TI in processed and complex food matrices and to investigate the influence of antibody batch variability on immunoassay performance. During method development, inconsistencies in Gly m TI detection prompted a comparative evaluation of several batches of anti-Gly m TI IgG using both the newly developed ELISA and an electrochemical immunosensor. The ELISA was optimised in terms of protein extraction, antibody concentration, and linear dynamic range, and successfully applied to model foods simulating biscuits, sausages, and cooked hams, achieving a limit of detection (LOD) of 1,000 mg/kg irrespective of matrix or processing. Given this limited sensitivity, antibody batch variability was further assessed across both ELISA and immunosensor. Antibodies obtained approximately at the same time showed comparable performance, whereas those acquired five years earlier differed substantially. In particular, antibodies of older batches (Ab1/Ab3) outperformed the most recent ones (Ab2/Ab4), exhibiting wider dynamic ranges, lower LOD (0.1 mg/kg), and requiring lower antibody concentrations. These results highlight the significant variability of commercial antibodies and its critical impact on immunoassay sensitivity and reproducibility in food allergen detection.

Abstract While heteroatom doping is widely used to enhance the fluorescence of carbon dots, the actual mechanism underlying this claimed enhancement remains unclear. Herein, we report a systematic comparison between nitrogen-doped carbon dots (N-CDs) and nitrogen/sulfur co-doped carbon dots (N,S-CDs) synthesized hydrothermally, with ethylenediamine and sodium thiosulfate as the N- and S-dopants, respectively. Contrary to expectations, the inclusion of the S-precursor significantly reduced the quantum yield by 63%, from 35.9% to 13.2%, while leaving the emission profile and response largely unchanged. Characterization assays revealed that S-doping in N,S-CDs was residual, whereas the surface oxygen content increased markedly, indicating surface oxidation. The data suggest that sodium thiosulfate acted not as a dopant but overall as an oxidant, generating oxygen-based surface defects that introduced nonradiative recombination pathways. Thus, our findings show that co-doping with this S-precursor can decrease the quantum yield by promoting surface oxidation and the effective formation of more oxidized N-CDs, rather than heteroatom incorporation and production of co-doped CDs. This decreasing effect on the quantum yield was also observed when using thiourea as the S-precursor. Future work should include the study of other common S-precursors. In conclusion, our research shows that specific heteroatom-based precursors can alter the optical characteristics of CDs through redox/surface-modification effects instead of actual compositional doping, and thus, claims based on heteroatom doping may need closer examination.

Abstract Food allergies are a growing global health concern, demanding reliable tools for allergen detection to ensure consumers' safety. This work proposes the development of sustainable carbon dots (CDs) as immunosensor bioreceptors for the sensitive quantification of soybean trypsin inhibitor (Gly m TI) in foods. CDs were synthesised via a green hydrothermal method using eucalyptus leaves as a precursor and integrated onto a gold electrode as a platform to enhance electron transfer, surface functionality, and antibody immobilisation. The resulting immunosensor, constructed with CDs-PAMAM-anti-Gly m TI IgG, exhibited good analytical performance, including a wide dynamic range (1 fg mL(-1) to 0.1 ng mL(-1)), a limit of detection (LOD) of 1 ag mL(-1) in buffer, and high specificity, as confirmed by adsorption isotherm modelling. Its applicability was further validated in complex non-/processed food matrices (dough/biscuits, and raw ham/cooked ham), where it maintained a robust performance (LOD <0.1 mg kg(-1)) regardless of matrix interferences and/or thermal processing effects. At this sensitivity level, the platform meets international food safety requirements, protecting more than 95% of soybean-allergic consumers worldwide. These findings demonstrate the potential of sustainable CDs-based nanointerfaces as eco-friendly, high-performance platforms for food allergen monitoring and future point-of-care diagnostics.

Abstract This work reports on the synthesis and electrochemical investigation of sustainable carbon-TiO2 nanocomposites derived from marine biowaste, designed to elucidate light-assisted charge storage mechanisms in non-aqueous electrolytes. Porous carbons obtained from prawn chitin and blue shark gelatin were decorated in situ with TiO2 nanoparticles using a deep eutectic solvent (DES) as a green synthesis medium. Structural and morphological characterisation revealed that TiO2 incorporation induces significant nanoscale reorganisation of the carbon framework, resulting in hierarchical porosity, increased surface area, and intimate semiconductor-carbon interfaces. Electrochemical evaluation in a three-electrode configuration using an ethaline-based DES electrolyte demonstrated that TiO2 decoration substantially enhances capacitive performance and cycling stability, with the prawn chitin-derived composite achieving a specific capacitance of 54 +/- 3 F g(-1) and 91% retention after 10,000 cycles. Under illumination, all TiO2-containing composites exhibited a pronounced increase in anodic current response and discharge time, indicating photo-assisted surface charge accumulation. Although the absolute capacitance values are modest compared to those of aqueous supercapacitor systems, the results provide mechanistic insight into the interplay among nanostructure, semiconductor photoactivity, and ion transport in viscous, hydrogen-bonded DES electrolytes. By combining waste-derived carbons, green synthesis routes, and photo-responsive nanostructures, this study highlights a sustainable strategy for developing multifunctional carbon-based nanomaterials with light-modulated electrochemical behaviour.

Abstract Abandoned mines are among the main sources of long-term soil contamination, often leaving behind persistent concentrations of potentially toxic elements (PTE) that pose environmental and health risks. Ribeiro da Serra Sb-Au mine, in Portugal, active from 1858 to 1890, has left a significant environmental legacy. This study mapped the spatial distribution of mine processing residues, elemental characterisation distinguishing between anthropogenic and natural enrichment by determining soil sample concentrations of PTE, Hg mobility, and Total Organic Carbon (TOC) quantification. Multivariate analysis, spatial interpolation and comparison with Enrichment Factor were employed with the aim of understanding the distributions and sources of PTEs in the soils. Mercury is still present at the site, revealing high mobile (18.72 mg kg(-1)) and semi-mobile (3.58 mg kg(-1)) concentrations accumulated in waste piles, a remnant of Au amalgamation processes. High Hg concentrations (20.75 mg kg(-1)) pose significant environmental risks, even after more than a century, such as bioaccumulation potential and soil toxicity. Also, there are high concentrations of Pb (449.03 mg kg(-1)) in the waste piles from the Sb processing. This study highlights the critical importance of interpreting natural enrichment values of elements of Hg (EF = 267) and Pb (EF = 18) to discern pollution pathways resulting from mining and processing activities. Interpretation of natural enrichment values leads to a more accurate evaluation of environmental contamination and its sources. The Enrichment Factor shows that Sb (EF = 133) and Hg (EF = 267) are the elements that present extremely high enrichment (EF > 40).

Abstract <jats:p>Educational robotics is increasingly recognized as a promising tool for innovation in teaching and learning. However, its successful integration in schools often depends on the availability of targeted professional development programs that support educators with no prior experience in this field. This study addresses this gap by presenting and evaluating the development and implementation of a training program specifically designed to equip educators with the knowledge, skills, and confidence to integrate robotics into early and primary education. The program, sfera.BOT, was designed as part of a regional educational initiative in Basilicata, Italy, and was conceived within T.I. Abilito, a national initiative that promotes educational inclusion; within this broader framework, however, the training pathway examined here was addressed to educators working with all children in mainstream early childhood and primary classrooms, rather than exclusively with children with disabilities. It followed a blended learning model and was grounded in hands-on exploration, collaborative planning, and weekly mentoring sessions. The research employed a qualitative approach to explore the experiences of four female educators from diverse backgrounds who completed the training. Data was collected through semi-structured interviews, a knowledge assessment questionnaire, and field observations. The findings reveal that participants acquired significant technical and pedagogical competencies, shifted from initial insecurity to confident implementation, and began to see themselves as potential trainers and change agents within their schools. Given the small, purposefully selected sample and the specific regional context, these findings are context-rich rather than statistically generalizable. The study underscores how well-structured, practical, and context-aware training can foster continuing professional development in the field of educational robotics.</jats:p>

Abstract The high costs of equipment and maintenance for Chemistry laboratories are a barrier to quality education in this science. However, the emergence of user-friendly and low-cost technological tools helps to mitigate this problem. This paper presents a STEM proposal for exploring distillation collaboratively in a remote laboratory with live data transmission and sharing online. The approach was analyzed by four teachers from Mozambique who, in that context, highlighted the positive potential for knowledge exchange between schools and cultures and the negative lack of technological means in schools for its implementation. They recognize great potential for implementation in higher education, as institutions have better resources. Thus, richer learning experiences can be promoted for all participants.

Abstract Student-centred learning requires a variety of approaches, such as inquiry-based learning and the tackling of authentic and problem-based learning activities, to make the teaching and learning process more meaningful and to encourage students to participate more actively in class. The inquiry approach enables students to investigate solutions to real problems, awakening their need to ask questions, design and conduct research, collect and analyse data, interpret results and present them in a structured way. This study investigates the influence of an inquiry-based science education (IBSE) module on the development of oral and written communication skills among 10th grade students. The study is set in a secondary school context and focuses on a problem-based learning approach centred around gases and dispersions. A total of 111 students participated in this one-group post-assessment qualitative study, where evaluation rubrics were applied to assess students' written and oral communication, focusing on correctness, clarity and mastery of scientific language. The results showed that the majority of students performed well in both written and oral tasks, demonstrating improved scientific communication skills. This suggests that IBSE, particularly in the context of secondary education, can be an effective approach to fostering students' abilities to communicate scientific concepts. The study has implications for enhancing pedagogical practices and encourages further research on the long-term effects of IBSE on student learning.