{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,1,23]],"date-time":"2026-01-23T09:40:49Z","timestamp":1769161249891,"version":"3.49.0"},"reference-count":49,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T00:00:00Z","timestamp":1700179200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UID\/FIS\/04650\/2013"],"award-info":[{"award-number":["UID\/FIS\/04650\/2013"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["UID\/FIS\/04650\/2019"],"award-info":[{"award-number":["UID\/FIS\/04650\/2019"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["PTDC\/NAN-MAT\/0098\/2020"],"award-info":[{"award-number":["PTDC\/NAN-MAT\/0098\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["POCI-01-0247-FEDER-045939"],"award-info":[{"award-number":["POCI-01-0247-FEDER-045939"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"Funda\u00e7\u00e3o para a Ci\u00eancia e Tecnologia","doi-asserted-by":"publisher","award":["2022.03564.PTDC"],"award-info":[{"award-number":["2022.03564.PTDC"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sustainability"],"abstract":"<jats:p>Hybrid biomaterials were engineered using the electrospinning technique, incorporating the dipeptide Boc\u2013L-phenylalanyl\u2013L-isoleucine into microfibers composed of biocompatible polymers. The examination by scanning electron microscopy affirmed the morphology of the microfibers, exhibiting diameters ranging between 0.9 and 1.8 \u00b5m. The dipeptide self-assembles into spheres with a hydrodynamic size between 0.18 and 1.26 \u00b5m. The dielectric properties of these microfibers were characterized through impedance spectroscopy where variations in both temperature and frequency were systematically studied. The investigation revealed a noteworthy rise in the dielectric constant and AC electric conductivity with increasing temperature, attributable to augmented charge mobility within the material. The successful integration of the dipeptide was substantiated through the observation of Maxwell\u2013Wagner interfacial polarization, affirming the uniform dispersion within the microfibers. In-depth insights into electric permittivity and activation energies were garnered using the Havriliak\u2013Negami model and the AC conductivity behavior. Very importantly, these engineered fibers exhibited pronounced pyroelectric and piezoelectric responses, with Boc\u2013Phe\u2013Ile@PLLA microfibers standing out with the highest piezoelectric coefficient, calculated to be 56 pC\/N. These discoveries help us understand how dipeptide nanostructures embedded into electrospun nano\/microfibers can greatly affect their pyroelectric and piezoelectric properties. They also point out that polymer fibers could be used as highly efficient piezoelectric energy harvesters, with promising applications in portable and wearable devices.<\/jats:p>","DOI":"10.3390\/su152216040","type":"journal-article","created":{"date-parts":[[2023,11,17]],"date-time":"2023-11-17T09:10:38Z","timestamp":1700212238000},"page":"16040","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":5,"title":["Electrospun Microstructured Biopolymer Fibers Containing the Self-Assembled Boc\u2013Phe\u2013Ile Dipeptide: Dielectric and Energy Harvesting Properties"],"prefix":"10.3390","volume":"15","author":[{"ORCID":"https:\/\/orcid.org\/0009-0005-7699-5563","authenticated-orcid":false,"given":"Adelino","family":"Handa","sequence":"first","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5380-9212","authenticated-orcid":false,"given":"Rosa M. F.","family":"Baptista","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Daniela","family":"Santos","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8408-8235","authenticated-orcid":false,"given":"Bruna","family":"Silva","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6094-1713","authenticated-orcid":false,"given":"Ana Rita O.","family":"Rodrigues","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Jo\u00e3o","family":"Oliveira","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Bernardo","family":"Almeida","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"given":"Etelvina","family":"de Matos Gomes","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-7968-5038","authenticated-orcid":false,"given":"Michael","family":"Belsley","sequence":"additional","affiliation":[{"name":"Centre of Physics of Minho and Porto Universities (CF-UM-UP), Laboratory for Materials and Emergent Technologies (LAPMET), University of Minho, Campus de Gualtar, 4710-057 Braga, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2023,11,17]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Shin, D.-M., Hong, S.W., and Hwang, Y.-H. (2020). Recent advances in organic piezoelectric biomaterials for energy and biomedical applications. Nanomaterials, 10.","DOI":"10.3390\/nano10010123"},{"key":"ref_2","first-page":"11","article-title":"Piezoelectric and ferroelectric properties of various amino acids and dipeptides tubular nanostructures: Molecular modeling","volume":"2","author":"Bystrov","year":"2020","journal-title":"Nanomater. Sci. Eng."},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"180","DOI":"10.1038\/nmat5045","article-title":"Control of piezoelectricity in amino acids by supramolecular packing","volume":"17","author":"Guerin","year":"2018","journal-title":"Nat. Mater."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"68","DOI":"10.1016\/j.jpcs.2016.02.002","article-title":"Piezoelectric properties of diphenylalanine microtubes prepared from the solution","volume":"93","author":"Vasilev","year":"2016","journal-title":"J. Phys. Chem. Solids"},{"key":"ref_5","unstructured":"Ramakrishnan, V., Patel, K., and Goyal, R. (2023). De Novo Peptide Design, Academic Press."},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"e23033","DOI":"10.1002\/bip.23033","article-title":"Self-assembly of t-butyloxycarbonyl protected dipeptide methyl esters composed of leucine, isoleucine, and valine into highly organized structures from alcohol and aqueous alcohol mixtures","volume":"108","author":"Subbalakshmi","year":"2017","journal-title":"Pept. Sci."},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"2744","DOI":"10.1039\/C0SM00897D","article-title":"Self-assembly of peptides: Influence of substrate, pH and medium on the formation of supramolecular assemblies","volume":"7","author":"Kumaraswamy","year":"2011","journal-title":"Soft Matter"},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"15632","DOI":"10.1021\/ja104373e","article-title":"Elementary Building Blocks of Self-Assembled Peptide Nanotubes","volume":"132","author":"Amdursky","year":"2010","journal-title":"J. Am. Chem. Soc."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"261907","DOI":"10.1063\/1.3167354","article-title":"Self-assembled bioinspired quantum dots: Optical properties","volume":"94","author":"Amdursky","year":"2009","journal-title":"Appl. Phys. Lett."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"849","DOI":"10.1038\/nnano.2009.298","article-title":"Self-assembled arrays of peptide nanotubes by vapour deposition","volume":"4","author":"Aronov","year":"2009","journal-title":"Nat. Nanotechnol."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"105","DOI":"10.2174\/157341306776875802","article-title":"Molecular self-assembly of peptide nanostructures: Mechanism of association and potential uses","volume":"2","author":"Reches","year":"2006","journal-title":"Curr. Nanosci."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"195","DOI":"10.1038\/nnano.2006.139","article-title":"Controlled patterning of aligned self-assembled peptide nanotubes","volume":"1","author":"Reches","year":"2006","journal-title":"Nat. Nanotechnol."},{"key":"ref_13","first-page":"2332","article-title":"The structure of nanotubes formed by diphenylalanine, the core recognition motif of Alzheimer\u2019s \u03b2-amyloid polypeptide","volume":"22","year":"2006","journal-title":"Chem. Commun."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"1263","DOI":"10.1039\/b605536m","article-title":"Self-assembled peptide nanostructures: The design of molecular building blocks and their technological utilization","volume":"36","author":"Gazit","year":"2007","journal-title":"Chem. Soc. Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"13566","DOI":"10.1038\/ncomms13566","article-title":"Self-assembly of diphenylalanine peptide with controlled polarization for power generation","volume":"7","author":"Nguyen","year":"2016","journal-title":"Nat. Commun."},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"963","DOI":"10.1016\/j.progpolymsci.2013.02.001","article-title":"Functional materials by electrospinning of polymers","volume":"38","author":"Agarwal","year":"2013","journal-title":"Prog. Polym. Sci."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"64","DOI":"10.1016\/S1359-0294(03)00004-9","article-title":"Polymer nanofibers assembled by electrospinning","volume":"8","author":"Frenot","year":"2003","journal-title":"Curr. Opin. Colloid Interface Sci."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"2223","DOI":"10.1016\/S0266-3538(03)00178-7","article-title":"A review on polymer nanofibers by electrospinning and their applications in nanocomposites","volume":"63","author":"Huang","year":"2003","journal-title":"Compos. Sci. Technol."},{"key":"ref_19","doi-asserted-by":"crossref","unstructured":"Santos, D., Baptista, R.M.F., Handa, A., Almeida, B., Rodrigues, P.V., Torres, A.R., Machado, A., Belsley, M., and de Matos Gomes, E. (2023). Bioinspired Cyclic Dipeptide Functionalized Nanofibers for Thermal Sensing and Energy Harvesting. Materials, 16.","DOI":"10.20944\/preprints202302.0365.v1"},{"key":"ref_20","doi-asserted-by":"crossref","unstructured":"Santos, D., Baptista, R.M.F., Handa, A., Almeida, B., Rodrigues, P.V., Castro, C., Machado, A., Rodrigues, M.J.L.F., Belsley, M., and de Matos Gomes, E. (2023). Nanostructured Electrospun Fibers with Self-Assembled Cyclo-L-Tryptophan-L-Tyrosine Dipeptide as Piezoelectric Materials and Optical Second Harmonic Generators. Materials, 16.","DOI":"10.20944\/preprints202306.1571.v1"},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Ramakrishna, S., Fujihara, K., Teo, W.-E., Lim, T.-C., and Ma, Z. (2005). An Introduction to Electrospinning and Nanofibers, World Scientific.","DOI":"10.1142\/5894"},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"5670","DOI":"10.1002\/anie.200604646","article-title":"Electrospinning: A Fascinating Method for the Preparation of Ultrathin Fibers","volume":"46","author":"Greiner","year":"2007","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"2332","DOI":"10.1002\/adma.200702802","article-title":"Electrospinning of diphenylalanine nanotubes","volume":"20","author":"Singh","year":"2008","journal-title":"Adv. Mater."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.progpolymsci.2019.01.002","article-title":"Electrospun polymer biomaterials","volume":"90","author":"Ding","year":"2019","journal-title":"Prog. Polym. Sci."},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"7025","DOI":"10.1021\/acsnano.0c01654","article-title":"Diphenylalanine-Derivative Peptide Assemblies with Increased Aromaticity Exhibit Metal-like Rigidity and High Piezoelectricity","volume":"14","author":"Basavalingappa","year":"2020","journal-title":"ACS Nano"},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1016\/j.nanoen.2018.06.061","article-title":"Piezoelectric diphenylalanine peptide for greatly improved flexible nanogenerators","volume":"51","author":"Jenkins","year":"2018","journal-title":"Nano Energy"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"1877","DOI":"10.1039\/b915765b","article-title":"Self-assembly and application of diphenylalanine-based nanostructures","volume":"39","author":"Yan","year":"2010","journal-title":"Chem. Soc. Rev."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"8138","DOI":"10.1021\/acsnano.8b03118","article-title":"Diphenylalanine Peptide Nanotube Energy Harvesters","volume":"12","author":"Lee","year":"2018","journal-title":"ACS Nano"},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"2934","DOI":"10.1039\/D1MA01022K","article-title":"Self-assembly of Boc-p-nitro-l-phenylalanyl-p-nitro-l-phenylalanine and Boc-l-phenylalanyl-l-tyrosine in solution and into piezoelectric electrospun fibers","volume":"3","author":"Baptista","year":"2022","journal-title":"Mater. Adv."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"4339","DOI":"10.1039\/C9NA00464E","article-title":"Self-assembly of dipeptide Boc-diphenylalanine nanotubes inside electrospun polymeric fibers with strong piezoelectric response","volume":"1","author":"Baptista","year":"2019","journal-title":"Nanoscale Adv."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"4373","DOI":"10.3390\/molecules18044373","article-title":"Chemical Methods for Peptide and Protein Production","volume":"18","author":"Chandrudu","year":"2013","journal-title":"Molecules"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"671","DOI":"10.1038\/nmeth.2089","article-title":"NIH Image to ImageJ: 25 years of image analysis","volume":"9","author":"Schneider","year":"2012","journal-title":"Nat. Methods"},{"key":"ref_33","doi-asserted-by":"crossref","unstructured":"Porter, S.L., Coulter, S.M., Pentlavalli, S., and Laverty, G. (2020). Pharmaceutical Formulation and Characterization of Dipeptide Nanotubes for Drug Delivery Applications. Macromol. Biosci., 20.","DOI":"10.1002\/mabi.202000115"},{"key":"ref_34","unstructured":"B\u00f6hmer, R., and Kremer, F. (2003). Broadband Dielectric Spectroscopy, Springer."},{"key":"ref_35","unstructured":"Kremer, F., and Sch\u00f6nhals, A. (2012). Broadband Dielectric Spectroscopy, Springer."},{"key":"ref_36","doi-asserted-by":"crossref","unstructured":"Abu Hassan Shaari, H., Ramli, M.M., Mohtar, M.N., Abdul Rahman, N., and Ahmad, A. (2021). Synthesis and Conductivity Studies of Poly(Methyl Methacrylate) (PMMA) by Co-Polymerization and Blending with Polyaniline (PANi). Polymers, 13.","DOI":"10.3390\/polym13121939"},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"108467","DOI":"10.1016\/j.compositesb.2020.108467","article-title":"Extensional flow-induced conductive nanohybrid shish in poly(lactic acid) nanocomposites toward pioneering combination of high electrical conductivity, strength, and ductility","volume":"203","author":"Xue","year":"2020","journal-title":"Compos. Part B Eng."},{"key":"ref_38","doi-asserted-by":"crossref","unstructured":"Poplavko, Y. (2021). Dielectric Spectroscopy of Electronic Materials, Woodhead Publishing.","DOI":"10.1016\/B978-0-12-823518-8.00001-3"},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"626","DOI":"10.1002\/pi.2010","article-title":"Stereocomplexed polylactides (Neo-PLA) as high-performance bio-based polymers: Their formation, properties, and application","volume":"55","author":"Fukushima","year":"2006","journal-title":"Polym. Int."},{"key":"ref_40","doi-asserted-by":"crossref","first-page":"9298","DOI":"10.1039\/C8TA00377G","article-title":"The quest for high glass transition temperature bioplastics","volume":"6","author":"Nguyen","year":"2018","journal-title":"J. Mater. Chem. A"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"123760","DOI":"10.1016\/j.polymer.2021.123760","article-title":"Peculiar \u03b1-\u03b2 relaxations of Syndiotactic-Poly (methyl methacrylate)","volume":"225","author":"Huang","year":"2021","journal-title":"Polymer"},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"051807","DOI":"10.1103\/PhysRevE.64.051807","article-title":"Dynamics of \u03b1 and \u03b2 processes in thin polymer films: Poly (vinyl acetate) and poly (methyl methacrylate)","volume":"64","author":"Fukao","year":"2001","journal-title":"Phys. Rev. E"},{"key":"ref_43","unstructured":"Wubbenhorst, M., Murray, C., Forrest, J., and Dutcher, J. (2002, January 3). Dielectric relaxations in ultra-thin films of PMMA: Assessing the length scale of cooperativity in the dynamic glass transition. Proceedings of the 11th International Symposium on Electrets, Melbourne, Australia."},{"key":"ref_44","doi-asserted-by":"crossref","first-page":"1002","DOI":"10.1021\/ma9913818","article-title":"Relaxation studies in PEO\/PMMA blends","volume":"33","author":"Fernandes","year":"2000","journal-title":"Macromolecules"},{"key":"ref_45","doi-asserted-by":"crossref","first-page":"46","DOI":"10.1016\/j.jascer.2015.11.006","article-title":"Dielectric and electrical properties of LiNbO3 ceramics","volume":"4","author":"Bennani","year":"2016","journal-title":"J. Asian Ceram. Soc."},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"79","DOI":"10.1016\/S0167-2738(00)00737-2","article-title":"Comparison of the universal dynamic response power-law fitting model for conducting systems with superior alternative models","volume":"133","author":"Macdonald","year":"2000","journal-title":"Solid. State Ion."},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"317","DOI":"10.1039\/C7CP04355D","article-title":"Polaron formation mechanisms in conjugated polymers","volume":"20","author":"Bombile","year":"2018","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_48","doi-asserted-by":"crossref","first-page":"560","DOI":"10.1038\/s41578-021-00289-w","article-title":"Polarons in materials","volume":"6","author":"Franchini","year":"2021","journal-title":"Nat. Rev. Mater."},{"key":"ref_49","doi-asserted-by":"crossref","first-page":"299","DOI":"10.1038\/s41428-019-0281-5","article-title":"Towards hydrophilic piezoelectric poly-L-lactide films: Optimal processing, post-heat treatment and alkaline etching","volume":"52","author":"Spreitzer","year":"2020","journal-title":"Polym. J."}],"container-title":["Sustainability"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/2071-1050\/15\/22\/16040\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,10,10]],"date-time":"2025-10-10T21:24:29Z","timestamp":1760131469000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/2071-1050\/15\/22\/16040"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2023,11,17]]},"references-count":49,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2023,11]]}},"alternative-id":["su152216040"],"URL":"https:\/\/doi.org\/10.3390\/su152216040","relation":{},"ISSN":["2071-1050"],"issn-type":[{"value":"2071-1050","type":"electronic"}],"subject":[],"published":{"date-parts":[[2023,11,17]]}}}