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dc.contributor.authorvon Witte, Gevin
dc.contributor.authorHimmler, Aaron
dc.contributor.authorHyppönen, Viivi
dc.contributor.authorJäntti, Jiri
dc.contributor.authorAlbannay, Mohammed M.
dc.contributor.authorMoilanen, Jani O.
dc.contributor.authorErnst, Matthias
dc.contributor.authorLehto, Vesa-Pekka
dc.contributor.authorRiikonen, Joakim
dc.contributor.authorKozerke, Sebastian
dc.contributor.authorKettunen, Mikko I.
dc.contributor.authorTamarov, Konstantin
dc.date.accessioned2024-10-23T04:59:57Z
dc.date.available2024-10-23T04:59:57Z
dc.date.issued2024
dc.identifier.citationvon Witte, G., Himmler, A., Hyppönen, V., Jäntti, J., Albannay, M. M., Moilanen, J. O., Ernst, M., Lehto, V.-P., Riikonen, J., Kozerke, S., Kettunen, M. I., & Tamarov, K. (2024). Controlled synthesis and characterization of porous silicon nanoparticles for dynamic nuclear polarization. <i>Nanoscale</i>, <i>Early online</i>. <a href="https://doi.org/10.1039/d4nr02603a" target="_blank">https://doi.org/10.1039/d4nr02603a</a>
dc.identifier.otherCONVID_243260310
dc.identifier.urihttps://jyx.jyu.fi/handle/123456789/97603
dc.description.abstractSi nanoparticles (NPs) have been actively developed as a hyperpolarized magnetic resonance imaging (MRI) contrast agent with an imaging window close to one hour. However, the progress in the development of NPs has been hampered by the incomplete understanding of their structural properties that correspond to efficient hyperpolarization buildup and long polarization decays. In this work we study dynamic nuclear polarization (DNP) of single crystal porous Si (PSi) NPs with defined doping densities ranging from nominally undoped to highly doped with boron or phosphorus. To develop such PSi NPs we perform low-load metal-assisted catalytic etching for electronic grade Si powder followed by thermal oxidation to form the dangling bonds in the Si/SiO2 interface, the Pb centers. Pb centers are the endogenous source of the unpaired electron spins necessary for DNP. The controlled fabrication and oxidation procedures allow us to thoroughly investigate the impact of the magnetic field, temperature and doping on the DNP process. We argue that the buildup and decay rate constants are independent of size of Si crystals between approximately 10 and 60 nm. Instead, the rates are limited by the polarization transfer across the nuclear spin diffusion barrier determined by the large hyperfine shift of the central 29Si nuclei of the Pb centers. The size-independent rates are then weakly affected by the doping degree for low and moderately doped Si although slight doping is required to achieve the highest polarization. Thus, we find the room temperature relaxation of low boron doped PSi NPs reaching 75 ± 3 minutes and nuclear polarization levels exceeding ∼6% when polarized at 6.7 T and 1.4 K. Our study thus establishes solid grounds for further development of Si NPs as hyperpolarized contrast agents.en
dc.format.mimetypeapplication/pdf
dc.language.isoeng
dc.publisherRoyal Society of Chemistry
dc.relation.ispartofseriesNanoscale
dc.rightsCC BY 4.0
dc.titleControlled synthesis and characterization of porous silicon nanoparticles for dynamic nuclear polarization
dc.typeresearch article
dc.identifier.urnURN:NBN:fi:jyu-202410236462
dc.contributor.laitosKemian laitosfi
dc.contributor.laitosDepartment of Chemistryen
dc.type.urihttp://purl.org/eprint/type/JournalArticle
dc.type.coarhttp://purl.org/coar/resource_type/c_2df8fbb1
dc.description.reviewstatuspeerReviewed
dc.relation.issn2040-3364
dc.relation.volumeEarly online
dc.type.versionpublishedVersion
dc.rights.copyright© The Royal Society of Chemistry 2024
dc.rights.accesslevelopenAccessfi
dc.type.publicationarticle
dc.relation.grantnumber338733
dc.subject.ysonanohiukkaset
dc.subject.ysopii
dc.subject.ysokemiallinen synteesi
dc.subject.ysomagneettikuvaus
dc.subject.ysopolarisaatio (aaltoliike)
dc.subject.ysonanotieteet
dc.format.contentfulltext
jyx.subject.urihttp://www.yso.fi/onto/yso/p23451
jyx.subject.urihttp://www.yso.fi/onto/yso/p15609
jyx.subject.urihttp://www.yso.fi/onto/yso/p8468
jyx.subject.urihttp://www.yso.fi/onto/yso/p12131
jyx.subject.urihttp://www.yso.fi/onto/yso/p4793
jyx.subject.urihttp://www.yso.fi/onto/yso/p6228
dc.rights.urlhttps://creativecommons.org/licenses/by/4.0/
dc.relation.datasethttps://doi.org/10.3929/ethz-b-000679152
dc.relation.doi10.1039/d4nr02603a
dc.relation.funderResearch Council of Finlanden
dc.relation.funderSuomen Akatemiafi
jyx.fundingprogramAcademy Project, AoFen
jyx.fundingprogramAkatemiahanke, SAfi
jyx.fundinginformationThe work was supported by Research Council of Finland (grant no. 314551, 331371, 322006, 338733 and Flagship of Advanced Mathematics for Sensing Imaging and Modelling grant 358944), ETH Zürich and the Schweizerischer Nationalfonds zur Förderung der Wissenschaftlichen Forschung (grant no. 200020_188988 and 200020_219375), Finnish Cultural Foundation (North Savo regional fund) and Saastamoinen Foundation. The microscopy studies were performed using the facilities of SIB Labs, Laboratory of Microscopy at the University of Eastern Finland. Part of the work was carried out with the support of Kuopio Biomedical Imaging Unit, University of Eastern Finland, Kuopio, Finland (part of Biocenter Kuopio, Finnish Biomedical Imaging Node, and EuroBioImaging). Silicon was provided by Elkem Silicon Products (Elkem ASA, Norway) and Okmetic (Okmetik Oy, Finland).
dc.type.okmA1


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