Publications

Abstract Urban parks are essential to sustainable cities, providing climate regulation, supporting biodiversity, and offering vital spaces for recreation and overall well-being. At the same time, their soils can act as long-term reservoirs for persistent organic pollutants (POPs), reflecting decades of atmospheric deposition, diffuse urban emissions, and historical land-use practices. This review synthesises current knowledge on the occurrence, sources, and environmental behaviour of priority POPs, including OCPs, PCBs, PCDD/Fs, PBDEs, PFAS, and PAHs, in the soils of urban parks and gardens worldwide. Evidence from multiple regions reveals consistent patterns: urban parks accumulate complex mixtures of legacy and emerging contaminants, reflecting both historical inputs and ongoing urban activities. These contaminants primarily contribute to scenarios of chronic, low-level exposure through the ingestion of soil and dust, inhalation of resuspended particles, dermal contact, and, in some cases, dietary intake when food is cultivated in contaminated park soils. While such exposure pathways have been associated with a range of adverse health outcomes in toxicological and epidemiological studies, the presence of POPs in park soils does not imply that urban parks represent hazardous environments. Instead, it emphasises the importance of proportionate, evidence-based assessments within spaces that yield substantial net benefits to public health. Despite growing research interest, significant gaps remain, including limited understanding of mixture toxicity, insufficient data on temporal trends, a lack of harmonised monitoring strategies, and the absence of exposure scenarios specifically tailored to recreational soils. This review also examines major international and European regulatory frameworks and soil-quality guideline approaches relevant to urban and recreational soils, identifying mismatches between scientific evidence and regulatory practice. By integrating perspectives from environmental chemistry, toxicology, urban ecology, and policy, this review highlights the importance of targeted monitoring and context-specific management strategies to ensure that urban parks remain safe, healthy, and equitable components of increasingly complex urban landscapes.

Abstract A point-of-care test (POCT) based on low-cost and highly sensitive disposable chips was designed for the sensitive and selective detection of proteins. In particular, a pollen-based plasmonic nanostructured probe coupled, for the first time, with biomimetic receptors custom-designed as molecularly imprinted nanoparticles (MIP-NPs) for protein recognition, was developed and interrogated by an extrinsic optical fiber (OF)-based scheme. To this purpose, bovine serum albumin (BSA) was chosen in a proof-of-concept frame as an example of a protein. © 2026 Optica Publishing Group under the terms of the Optica Open Access Publishing Agreement.

Abstract <jats:p>Pollution of soils by heavy metals (HM) is a concerning result of anthropogenic activities. Iron (Fe) and silver (Ag) are HM-deemed essential and non-essential for plants and can induce toxicity when in excess. Metallothioneins (MTs) are small Cys-rich proteins involved in HM binding and oxidative stress mitigation. This study focused on Arabidopsis thaliana MTs types I, II, and III involvement in response to increasing concentrations of Fe and Ag in an organ-specific way - shoots and roots - through RT-qPCR analysis 21 days after germination, as well as biometric and biochemical assessments. The in vivo heterologous expression of AtMT2b in Nicotiana tabacum leaves was performed. Both HM reduced plant growth, with Fe accumulating dose-dependently in both shoots and roots, while Ag mainly accumulated in roots, albeit only at the highest concentration in shoots. Fe exposure caused little change in MT expression, whereas Ag strongly induced it in shoots and, to a lesser extent, in roots (particularly AtMT1a and AtMT1c). Biochemical analyses revealed distinct stress responses: Fe increased lipid peroxidation (MDA) and antioxidant compounds (GSH, thiols) mainly in shoots, while Ag triggered oxidative metabolism predominantly in shoots, with elevated HO, MDA, GSH, thiols, and proline levels. Both HM reduced photosynthetic pigments, notably -carotenes with Fe, and chlorophylls, lutein, and -carotenes with Ag. In vivo localisation showed AtMT2b to be cytosolic. Overall, Fe and Ag induced stress in A. thaliana with organ-specific responses, and MTs played a minor role in Fe tolerance but were strongly activated by Ag, especially in shoots.</jats:p>

Abstract The ability to assess molecular binding kinetics in real time is critical for advancing our understanding of molecular interactions in biochemical and biotechnological systems. This work presents a novel optical tweezer (OT)-based method to monitor molecular affinity in real time, focusing on the high-affinity streptavidin-biotin system as a model. Transparent poly(methyl methacrylate) (PMMA) microparticles functionalized with streptavidin were trapped before, during, and after binding with biotinylated bovine serum albumin (biotin-BSA), enabling the analysis of forward-scattered signals to detect nanoscale changes in particle size. By applying the Power Spectral Density method, the friction coefficient of individual particles was calculated, allowing for real-time tracking of binding dynamics and the estimation of the association rate constant (kon approximate to 106M-1s-1). These results are consistent with literature values and demonstrate the potential of this OT-based approach for non-invasive, label-free detection of molecular interactions. Compared to existing techniques, such as atomic force microscopy and cantilever-based sensors, this method offers significant advantages, including real-time monitoring, adaptability to different bioaffinity systems, and compatibility with miniaturized setups. This work establishes a foundation for using OT-based tools to monitor high-affinity molecular interactions in real time. While demonstrated here using biotinylated BSA as a model ligand, future studies will explore the method's applicability to smaller ligands and more subtle surface modifications.

Abstract The transportation sector plays a vital role in managing urban solid waste (USW) and significantly contributes to greenhouse gas (GHG) emissions. This study assesses the carbon footprint of USW collection in Fornos de Algodres, a municipality of Portugal, by comparing diesel trucks and electric trucks under various electricity supply scenarios. The analysis utilizes real-world operational data, including fuel and electricity consumption, emission factors, and vehicle efficiency. The results indicate that electrifying the waste collection fleet can reduce CO₂ emissions by between 29.3% and 87.1%, depending on the electricity supplier and the energy consumption of the trucks. Currently, the municipality sources electricity from Suppliers A and B, with Supplier A resulting in lower emissions (4259–8845 kgCO₂eq per year) compared to Supplier B (9,363–19,445 kgCO₂eq per year). A cleaner option, Supplier C, has the potential to further reduce emissions (3549–7371 kgCO₂eq per year) due to its more favourable energy mix. The findings emphasize that electrification alone is insufficient to fully maximize environmental benefits—the carbon footprint of electric trucks largely depends on energy efficiency and the electricity mix used. To optimize GHG reductions, municipalities should combine fleet electrification with cleaner electricity sources. This study offers valuable insights for policymakers and waste management companies, supporting goals related to sustainable urban mobility and climate action. Future research should focus on the economic feasibility, operational costs, and integration of renewable energy sources to further enhance sustainability. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.

Abstract This study analyses the Portuguese Corporate Income Tax (CIT) exemption provided under Article 53 of the Tax Benefits Code (TBC). This exemption applies exclusively to entities responsible for managing integrated systems of specific waste flows, such as packaging, tyres, used oils and electronic equipment, batteries and accumulators, and end-of-life vehicles. Duly licensed under the General Waste Management Regime (WMR), these entities benefit from tax exemption on reinvested profits or those allocated to legally designated purposes. The results show that, between 2013 and 2022, this exemption was used by the eligible entities despite the amounts claimed annually being relatively modest compared to the total tax benefits granted by the Portuguese government. This may be attributed to the limited number of entities eligible, given the legal requirement for licensing under the WMR, and to the narrow scope of the benefit itself, which applies only to profits that are either reinvested or allocated to legally defined purposes. Nevertheless, this measure has the potential to contribute to the sector’s economic competitiveness, ensuring reinvestment in technology and more efficient processes, strengthening beneficiary entities’ role in promoting the circular economy and the implementation of the European Union directives for waste management. It will also specify the Portuguese tax system's ability to integrate environmental objectives into public policies, highlighting the relevance of extra-fiscal instruments in driving the green transition and supporting the achievement of the global Sustainable Development Goals (SDGs). © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.

Abstract Waste separation is a crucial step toward sustainable waste management. Understanding public perception and participation in this process is essential for its success. This study evaluates public perception and participation in the selective collection of general waste and biowaste in Guarda, Portugal, identifying key motivations, barriers, and areas for improvement. A cross-sectional analytical study was conducted using an online survey with 205 residents. Results indicate that 83.4% (95% CI: 77.9%-88.0%) of participants separate waste in the household, while workplace separation is lower (65.9%, 95% CI: 59.2%-72.1%). Paper and cardboard are the most frequently separated materials, whereas used cooking oil receives the least attention (95% CI: 16.5%-30.6%). Regarding biowaste, 92.2% (95% CI: 87.9%-95.3%) of respondents understand the concept, and all recognize its environmental benefits. However, 43.4% (95% CI: 36.8%-50.3%) are unaware of the municipal biowaste collection network, and 57.1% (95% CI: 50.2%-63.7%) find the existing infrastructure inadequate. Municipalities should expand and optimize waste collection systems to improve participation while strengthening public awareness campaigns. Social media is the preferred information channel (91.2%, 95% CI: 86.8%-94.5%), but traditional outreach methods, such as school initiatives and community meetings, could enhance engagement. Addressing infrastructure gaps and promoting consistent separation practices across different settings are key to optimizing waste management. This study highlights the need for improved public engagement and infrastructure to ensure the success of selective waste collection, particularly for biowaste, contributing to enhanced sustainability efforts in the region. © The Author(s), under exclusive license to Springer Nature Switzerland AG 2026.

Abstract Haemoglobin (Hb) concentration is a key biomarker for several diseases. Traditional laboratory methods often have limitations due to their time-consuming nature, the need for skilled personnel, or the use of high-cost instrumentation. This work presents a sensing strategy for developing new point-of-care tests (POCTs) for Hb detection via a proof of concept. The proposed sensing approach is implemented using plasmonic plastic optical fiber (POF) sensor chips that integrate an electropolymerized molecularly imprinted polymer (eMIP) film on the plasmonic surface for Hb-selective detection. The developed sensor system demonstrates an ultra-low detection limit of 80 fM in buffer, about five orders of magnitude lower than that of other comparable Hb sensors. Selectivity tests against common interfering proteins, such as bovine serum albumin (BSA) and immunoglobulin G (IgG), confirmed high specificity towards the target analyte. Moreover, the sensor's performance was tested using a whole-blood sample, yielding results consistent with those of standard haematology analysis. The proposed sensor system, based on simple equipment, provides a quick (about 10 min) and cost-effective (about 10 euros per chip) label-free diagnostic tool for POCTs in real-world scenarios, such as finger-prick sampling, offering a less invasive alternative to traditional laboratory methods, towards devices useful for Internet of Medical Things (IoMT).

Abstract Detection of leaks in hydrogen (H2) infrastructure is required on a large scale to enable a safe widespread use of this clean energy source. Sensing solutions must be low-cost, use scalable fabrication methods and allow multiplexed detection while providing reliable safety alarms as fast as possible. Optical methods can make this possible while avoiding the risk of ignition due to electronics at the point of detection. Metal hydride-based micro-mirror configurations benefit from a simple interrogation scheme, as long as the sensitive element can produce a large optical response. Magnesium thin films undergo a drastic variation of properties when hydrogenated, making them suitable for this application. In this work, a micro-mirror device using single-mode fibers capable of detecting the presence of H2 with a loading t10 and t90 of 1.2 and 3.0 s, respectively, is demonstrated. A complete interrogation unit was developed, presenting a solution suited for widespread deployment using industry-standard optical components and equipment.

Abstract Concrete structures require precise temperature and humidity monitoring during curing to ensure optimal strength and to prevent defects such as cracking. A compact optical sensing system was developed using a single fiber that can be embedded directly within the concrete. When paired with a spectral interrogation unit operating in the low-loss single-mode communications band of 1500-1600 nm, the system functions as both a temperature and relative humidity (RH) sensor. Temperature monitoring is achieved using a Fiber Bragg Grating, while humidity sensing is provided by a Fabry-Perot interferometer (FPI) at the fiber tip. The interferometer cavity is formed with a layer of polyvinylpyrrolidone (PVP), an RH-sensitive polymer. The system exhibited a response time of approximately 3 h and operated over a relative humidity range of 50-95% RH and a temperature range of 30-60 degrees C, with normalized free spectral range sensitivities of the FPI up to 35 m(-1)/%RH at high humidity levels. The system was validated using a small-scale 50-day in-concrete test.