A. Aliabadi, M. S. Rahmanifar, B. Sohrabi, H. Aghaei and K. Zare
{"title":"Capacitive behavior of electrodes prepared using tragacanth gum modified at various ratios and temperatures","authors":"A. Aliabadi, M. S. Rahmanifar, B. Sohrabi, H. Aghaei and K. Zare","doi":"10.1039/D5MA00328H","DOIUrl":"https://doi.org/10.1039/D5MA00328H","url":null,"abstract":"<p >In the fields of energy conversion and storage, renewable, affordable, and environmentally benign electrode materials have garnered a lot of interest. Tragacanth gum (TG), a natural polymer, exhibits a high degree of biocompatibility; however, it is still difficult to obtain high conductivity. This study uses a TG carbon precursor and ZnCl<small><sub>2</sub></small> as an active agent at 600–900 °C for 2 hours under an N<small><sub>2</sub></small> atmosphere, which, to the best of our knowledge, is a simple approach for creating porous carbon materials with a high nitrogen content. The resulting TGN-3 sample has a nitrogen content of up to 1.23 weight percent and a high specific surface area of 3595.77 m<small><sup>2</sup></small> g<small><sup>−1</sup></small>. Additionally, the N-doped carbon shows good electrochemical properties (with a specific capacitance of 124.78 F g<small><sup>−1</sup></small> in 6 M KOH at a current density of 1 A g<small><sup>−1</sup></small>). Moreover, a TGN-3@Ni composite was prepared from the sustainable carbon source TGN-3 using a straightforward hydrothermal synthesis process. As an electrode material, it demonstrated good electrochemical properties with high rate capability and a specific capacitance of 319.9 F g<small><sup>−1</sup></small> in 6 M KOH at a current density of 5 A g<small><sup>−1</sup></small>. Then, using TGN-3 as the negative electrode, TGN-3@Ni as the positive electrode, and 6 M KOH as the electrolyte solution, an asymmetric supercapacitor (ASC) was fabricated. With a specific capacitance of 40.06 F g<small><sup>−1</sup></small> at 1 A g<small><sup>−1</sup></small> and a high energy density of 16.07 Whkg<small><sup>−1</sup></small> at a power density of 881.07 W kg<small><sup>−1</sup></small>, this supercapacitor demonstrated good electrochemical performance. It also demonstrated exceptional cycle stability, maintaining 96.12% of its initial specific capacitance after 8000 cycles at 5 A g<small><sup>−1</sup></small>. Consequently, these experimental results confirm that porous carbon materials with a high nitrogen content can be prospective electrode materials for supercapacitors.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 20","pages":" 7535-7551"},"PeriodicalIF":4.7,"publicationDate":"2025-09-04","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00328h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145284150","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Evangelia Tsitsou, Danai Prokopiou, Athina Papadopoulou, Alexandros K. Bikogiannakis, Georgios Kyriakou, Elias Sakellis, Nikos Boukos, Marios Kostakis, Nikolaos S. Thomaidis and Eleni K. Efthimiadou
{"title":"Engineering of two-in-one Fe@Eu nanoparticles through hydrothermal synthesis: bimetallic hybrids for theranostic applications","authors":"Evangelia Tsitsou, Danai Prokopiou, Athina Papadopoulou, Alexandros K. Bikogiannakis, Georgios Kyriakou, Elias Sakellis, Nikos Boukos, Marios Kostakis, Nikolaos S. Thomaidis and Eleni K. Efthimiadou","doi":"10.1039/D5MA00659G","DOIUrl":"https://doi.org/10.1039/D5MA00659G","url":null,"abstract":"<p >This study focuses on the synthesis of bimetallic Fe@Eu hybrid nanoparticles (NPs), combining structural and morphological characterization with an <em>in vitro</em> biological evaluation. By merging the superparamagnetic behavior of iron oxide nanoparticles (IONPs) with the distinctive optical properties of europium, these hybrid NPs emerge as strong candidates for a range of biomedical applications, particularly in cancer imaging and therapy. Magnetic IONPs were synthesized <em>via</em> co-precipitation and surface-modified with citrate to enhance colloidal stability. Europium was then introduced at varying Fe : Eu molar ratios (1 : 3, 1 : 1, and 1 : 0.25). Structural and morphological characterization confirmed the successful fabrication of the hybrids. DLS analysis demonstrated the excellent colloidal stability required for biomedical deployment. FT-IR, pXRD, and XPS verified the formation of magnetite and the successful incorporation of europium, which appeared as europium hydroxide nanorods. TEM elemental mapping further confirmed the co-existence of iron and europium within the same nanostructures. PL measurements revealed dual fluorescence capabilities, corroborated by widefield optical fluorescence microscopy, reinforcing their potential in multimodal imaging. <em>In vitro</em> studies showed efficient cellular internalization with minimal cytotoxicity. Mechanistic insights pointed to mild cell cycle disruption, moderate ROS generation, and apoptosis induction as part of the NPs’ biological activity.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 20","pages":" 7552-7573"},"PeriodicalIF":4.7,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00659g?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145284151","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Safaa Altves, Nezahat Gokce Ozsamur, Emrah Kavak and Sundus Erbas-Cakmak
{"title":"Modulation of P. aeruginosa quorum sensing and host immune response with biomimetic cyclodextrin enzyme models","authors":"Safaa Altves, Nezahat Gokce Ozsamur, Emrah Kavak and Sundus Erbas-Cakmak","doi":"10.1039/D5MA00162E","DOIUrl":"https://doi.org/10.1039/D5MA00162E","url":null,"abstract":"<p >Scientists working in the field of biomimetic nanomaterials are usually inspired by evolutionary strategies. Bacteria evaluate their own population density and disease causing processes through a unique chemical communication. Language used for this communication, quorum sensing (QS), has been determined to be <em>N</em>-acyl-homoserine lactones (AHLs) for most of the bacteria. AHL hydrolysis by the lactonase enzymes (cysteine hydrolases or metalloenzymes) of host species is known to inhibit QS. Here, we present the first biomimetic quorum quenching approach with the use of supramolecular enzyme mimetics. Thiol bearing (<strong>CD-SH</strong>) and metal chelated (<strong>CD–Cu(<small>II</small>)</strong>) cyclodextrin derivatives are shown to modulate bacterial quorum sensing, and <strong>CD-SH</strong> interferes with the inflammatory immune response of <em>P. aeruginosa</em>-infected host human lung cells. Like natural defensive enzymes against bacteria, CD-based enzyme mimetics with a hydrophobic binding pocket reduce pyocyanin production in <em>P. aeruginosa</em>, modulate QS, and reduce biofilm formation. The viability of infected lung cancer cells is significantly restored, and mucin and interleukin expressions are reduced upon treatment with <strong>CD-SH</strong>. Considering the role of cytokines and mucin glycoproteins in cystic fibrosis pathogenesis, bacterial attachment and accumulation, the host immune modulatory effect of artificial enzyme mimetics can pave the way for the development of potential new treatment modality for patients suffering from CF.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 6970-6977"},"PeriodicalIF":4.7,"publicationDate":"2025-09-03","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00162e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184031","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Natalie Nussbaum, Laura Balmelli, Nadja Steiger, Laura Nyström, Peter Fischer and Patrick A. Rühs
{"title":"Quantifying fungal growth in 3D: an ergosterol-based method to distinguish growth modes","authors":"Natalie Nussbaum, Laura Balmelli, Nadja Steiger, Laura Nyström, Peter Fischer and Patrick A. Rühs","doi":"10.1039/D5MA00811E","DOIUrl":"https://doi.org/10.1039/D5MA00811E","url":null,"abstract":"<p >Mycelium colonization of fungi on solid substrates occurs in three dimensions: hyphal extension on the substrate surface, mycelium network densification, and invasive hyphal growth into the substrate. Quantifying fungal biomass in three dimensions presents a challenge, because current methods either require the separation of mycelium from the host material or rely on pure 2D optical density measurements. Here, we quantitatively assessed fungal growth of <em>Ganoderma sessile</em> by measuring ergosterol, a sterol specific to fungi that effectively represents biomass estimation. To investigate and quantify the global fungal growth in 3D, we focused on two primary growth profiles: extensive growth, describing lateral colonization of hyphae across the substrate surface, and local growth, reflecting invasive penetration into the substrate and mycelium network densification. Distinguishing between these regimes is critical, as they contribute differently to biomass distribution and substrate interaction, enabling a more accurate and functionally relevant assessment of fungal growth in 3D systems. By measuring local and global ergosterol accumulation, we estimated that extensive growth contributes around 300 times more to global biomass accumulation than local growth. By altering the nutrient density and stiffness of the host materials, we assessed whether global biomass accumulation is primarily driven by extensive or local growth increase. Our results demonstrate that the common assumption that radial extension corresponds to biomass increase is not correct and consequently, not a reliable method for comparing fungal strains or growth conditions when interested in fungal biomass. Therefore, using ergosterol to measure the local and global growth allows the quantification of the contribution of both growth profiles to the final global biomass accumulation, providing an approach that can quantify the effects of substrate morphology and nutrient density.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 20","pages":" 7261-7272"},"PeriodicalIF":4.7,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00811e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145284124","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"One-step solvothermal synthesis of nickel–cobalt sulfides in a low coordination 1,4-dioxane solvent for supercapacitors","authors":"Yao Lei, Qiwei Xu, Yiru Miao and Jiarong Shi","doi":"10.1039/D5MA00795J","DOIUrl":"https://doi.org/10.1039/D5MA00795J","url":null,"abstract":"<p >Renowned for their exceptional specific capacity, high rate performance and good cycling stability, nickel–cobalt sulfides (NCSs) are highly promising electrode materials for supercapacitors. Unlike previous hydrothermal or solvothermal techniques that rely on solvents with strong polarity, high coordination ability and good solubility for synthesizing NCSs, this study employs solvents with low coordination and solubility ability for metal ions. These differences subsequently influence the macroscopic characteristics of the resultant materials. Specifically, the common solvent 1,4-dioxane with low coordination ability was employed. NCSs were synthesized using a straightforward one-step solvothermal method at different temperatures. NCS-180, synthesized at 180 °C, displays a sea urchin-like crystalline structure with aggregated linear nickel cobalt sulfide and demonstrates superior electrochemical performance. At a current density of 1 A g<small><sup>−1</sup></small>, it exhibits a specific capacity of 664.30 C g<small><sup>−1</sup></small>. Moreover, after enduring 5000 cycles at 10 A g<small><sup>−1</sup></small>, its capacity retention rate remains at 97.99%. Additionally, a dual-electrode configuration was constructed, utilizing NCS-180 as the cathode and activated carbon (AC) as the anode. The findings reveal that the NCS-180//AC system demonstrates a notable energy density of 50.35 Wh kg<small><sup>−1</sup></small> at a power density of 750 W kg<small><sup>−1</sup></small>. Furthermore, after enduring 6000 cycles at 10 A g<small><sup>−1</sup></small>, the system retains a capacitance retention rate of 93.30%.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 20","pages":" 7427-7435"},"PeriodicalIF":4.7,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00795j?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145284140","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Antonello Nucera, Rita Guzzi, Giovanni Desiderio, Antonio Ferraro, Giovanni Dal Poggetto, Marco Castriota and Oriella Gennari
{"title":"Size and surface properties of polydopamine nanoparticles tunable via controlled oxidation conditions","authors":"Antonello Nucera, Rita Guzzi, Giovanni Desiderio, Antonio Ferraro, Giovanni Dal Poggetto, Marco Castriota and Oriella Gennari","doi":"10.1039/D5MA00359H","DOIUrl":"https://doi.org/10.1039/D5MA00359H","url":null,"abstract":"<p >Polydopamine nanoparticles (PDA NPs) have emerged as a versatile biomimetic material with tunable physicochemical properties, making them promising candidates for applications in biomedicine, energy storage, and photothermal therapy. In this study, we investigate the structural and functional evolution of PDA NPs synthesized under controlled oxidation conditions, emphasizing the interplay between molecular crosslinking, surface roughness, and optical properties. A systematic analysis using SEM, FTIR, and Raman spectroscopy reveals a progressive transformation of catechol (–OH) groups into quinones, leading to increased π–π stacking and crosslinking, which modulates both electronic and photothermal behaviour. Dynamic light scattering (DLS) analysis identified 24 hours as the optimal synthesis window, yielding uniform and colloidally stable nanoparticles (<em>D</em><small><sub>H</sub></small> ≈ 154 nm; <em>ζ</em>-potential ≈ –41 mV). At early oxidation stages (1–24 h), the high availability of free catechol and amine groups supports enhanced electron delocalization, while at intermediate oxidation times (48 h), excessive crosslinking restricts charge mobility, limiting functional performance. Prolonged oxidation (96–120 h) results in increased roughness, influencing both light absorption and heat diffusion. Comparative photothermal analysis with <em>Sepia melanin</em> demonstrates that PDA NPs exceed the thermal performance of natural eumelanin in both tunability and photothermal conversion efficiency, reaching a Δ<em>T</em> ≈ 48.9 °C, for the 120 h oxidation NPs. The findings highlight the critical role of oxidation-driven molecular modifications in defining PDA's optical and thermal performance. These insights establish a structure–property framework for optimizing PDA NPs for life science applications.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 6956-6969"},"PeriodicalIF":4.7,"publicationDate":"2025-09-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00359h?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184030","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Akram Rahro, Alireza Salimi Beni and Somayeh Abaeezadeh
{"title":"A guanidine-functionalized graphene oxide/Fe3O4 nanocomposite as a magnetically recoverable heterogeneous catalyst for the Hantzsch reaction","authors":"Akram Rahro, Alireza Salimi Beni and Somayeh Abaeezadeh","doi":"10.1039/D5MA00318K","DOIUrl":"https://doi.org/10.1039/D5MA00318K","url":null,"abstract":"<p >In this study, a guanidine-functionalized graphene oxide/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small> nanocomposite (Gu-GO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small>) was synthesized and demonstrated as an efficient and magnetically recoverable catalyst for the synthesis of polyhydroquinoline derivatives <em>via</em> the unsymmetrical Hantzsch reaction under mild conditions. The catalyst was produced by the covalent immobilization of guanidine onto a 3-chloropropyl triethoxysilane-modified graphene/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small> support. The synthesized Gu-GO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small> nanocatalyst was characterized using FT-IR, SEM, VSM, XRD, and TGA. Optimization studies for the unsymmetrical Hantzsch reaction revealed that 0.005 g of Gu-GO/Fe<small><sub>3</sub></small>O<small><sub>4</sub></small> at 50 °C under solvent-free conditions afforded good to excellent product yields. The catalyst exhibited facile magnetic recovery using an external magnet and retained its catalytic activity and structural integrity after nine reuse cycles. A hot-filtration experiment confirmed the heterogeneous nature of the catalytic system.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 6944-6955"},"PeriodicalIF":4.7,"publicationDate":"2025-09-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00318k?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184029","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Nikhil Pais, Manav Jeetendra Shirodkar and Poornima Bhagavath
{"title":"Metal oxide doped organic thin film transistors: a comprehensive review","authors":"Nikhil Pais, Manav Jeetendra Shirodkar and Poornima Bhagavath","doi":"10.1039/D5MA00231A","DOIUrl":"https://doi.org/10.1039/D5MA00231A","url":null,"abstract":"<p >In recent years, organic thin film transistors (OTFTs) have been gaining widespread interest for electronic displays, circuits and sensors over traditional silicon-based transistors due to their unique properties such as low cost, mechanical and electrical stability, low-temperature processability and large-area processability. They are widely used in applications pertaining to flexible displays, wearable devices, radio frequency identification (RFID) tags, e-skin, biosensors, and flexible integrated circuits. However, organic thin film transistors are still inferior to silicon-based technologies, trailing behind in several critical performance metrics such as low mobilities and high operational voltages. These challenges can be mitigated using metal oxides, which, owing to their high work function and stability, can enhance the parameters of OTFT devices. This review aims to provide insights into the usage of metal oxides in organic thin film transistors and highlight their contribution as hole injection layers (HILs), charge transport complexes (CTCs), bilayer source–drain (S–D) electrodes and gate dielectrics.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 6664-6681"},"PeriodicalIF":4.7,"publicationDate":"2025-08-30","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00231a?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145183978","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Chung-Hao Chen, Yaiza Lozano Vilches, David Levy and Ingo Dierking
{"title":"A comparison of smart window approaches with polymer-modified and gel-glass dispersed liquid crystals","authors":"Chung-Hao Chen, Yaiza Lozano Vilches, David Levy and Ingo Dierking","doi":"10.1039/D5MA00646E","DOIUrl":"https://doi.org/10.1039/D5MA00646E","url":null,"abstract":"<p >Various approaches to smart windows, including polymer-stabilised, polymer-dispersed, and gel-glass dispersed liquid crystals (GDLC), are discussed with respect to their electro-optic performance based on diffuse reflectivity. The diffuse backward scattering of different devices under an electric field is analysed in detail. The study focuses on the novelty of GDLCs, which utilised a sol–gel derived matrix embedded with a nematic liquid crystal. The unique porous architecture and surface anchoring of GDLCs enhances the electro-optic properties. A comparison between three polymer-modified liquid crystal systems and the GDLC system demonstrates that GDLC provide new opportunities for optical devices, exhibiting lower switch-on voltage, smaller voltages required to achieve stable states and small voltage hysteresis.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 7067-7075"},"PeriodicalIF":4.7,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00646e?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184055","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Amanda E. Sabaine, Ana C. H. Castro-Kochi, Rodrigo S. N. Mancini, Marcos R. A. Silva, Anderson F. Sepulveda, Jamille R. Oliveira, Cesar Remuzgo, Keity S. Santos, Vivian L. Oliveira, Leandro T. Kochi, Lauro T. Kubota, Mónica B. Mamián-López and Wendel A. Alves
{"title":"Peptide-based biosensors for variant-specific detection of SARS-CoV-2 antibodies†","authors":"Amanda E. Sabaine, Ana C. H. Castro-Kochi, Rodrigo S. N. Mancini, Marcos R. A. Silva, Anderson F. Sepulveda, Jamille R. Oliveira, Cesar Remuzgo, Keity S. Santos, Vivian L. Oliveira, Leandro T. Kochi, Lauro T. Kubota, Mónica B. Mamián-López and Wendel A. Alves","doi":"10.1039/D5MA00485C","DOIUrl":"https://doi.org/10.1039/D5MA00485C","url":null,"abstract":"<p >The pandemic has highlighted an urgent demand for reliable methods to track immunological responses against SARS-CoV-2, especially in vaccinated populations and recovered patients. In this study, we developed biosensors based on the immunodominant peptide P44 (sequence: TGKIADYNYKLPDDF), located in a mutation hotspot of the Spike protein's receptor-binding domain (RBD), to enable the ultrasensitive and specific detection of antibodies against SARS-CoV-2. Gold nanoparticles (AuNPs, ∼30 nm) were synthesized <em>via</em> the Turkevich method and functionalized with P44-WT (wild-type) and its mutated forms, P44-T (gamma) and P44-N (beta), using 4-mercaptobenzoic acid (MBA) as a stabilizer. Functionalization was confirmed by UV-vis spectroscopy and dynamic light scattering (DLS), which revealed shifts in the plasmonic band and increases in the hydrodynamic radius. The optical biosensor, based on surface-enhanced Raman spectroscopy (SERS), analyzed convalescent and control sera (<em>n</em> = 104) using partial least squares discriminant analysis (PLS-DA), achieving 100% sensitivity and 76% specificity. Complementary electrochemical impedance spectroscopy (EIS) on glassy carbon electrodes corroborated the peptide–antibody interaction, yielding detection limits of 0.43, 4.85, and 8.04 ng mL<small><sup>−1</sup></small> for P44-WT, P44-T, and P44-N, respectively. The platform demonstrated high specificity in complex serum matrices and was unaffected by nonspecific biofouling. Our findings underscore the importance of peptide selection and optimization in enhancing biosensor performance and demonstrate the adaptability of this methodology for detecting emerging infectious diseases.</p>","PeriodicalId":18242,"journal":{"name":"Materials Advances","volume":" 19","pages":" 7090-7103"},"PeriodicalIF":4.7,"publicationDate":"2025-08-29","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/ma/d5ma00485c?page=search","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145184057","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"OA","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}