{"entity": "researcher", "timestamp": "2026-08-20T20:35:41.394Z", "family": "Raja", "given": "Shyamprasad N", "initials": "SN", "orcid": "0000-0002-2278-1368", "affiliations": ["Division of Micro and Nanosystems (MST), School of Electrical Engineering and Computer Science (EECS), KTH Royal Institute of Technology, SE-10044 Stockholm, Sweden."], "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/researcher/58df34262ccf4569b54162cfd38525be.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/researcher/58df34262ccf4569b54162cfd38525be"}}, "publications": [{"entity": "publication", "iuid": "09baeb2926c4435d9f51285afdea06bb", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/09baeb2926c4435d9f51285afdea06bb.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/09baeb2926c4435d9f51285afdea06bb"}}, "title": "Sub-5 nm Silicon Nanopore Sensors: Scalable Fabrication via Self-Limiting Metal-Assisted Chemical Etching.", "authors": [{"family": "De Ferrari", "given": "Fabio", "initials": "F", "orcid": "0000-0003-0960-9931", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/21be7bf528794d57b0b1431da2a95247.json"}}, {"family": "Raja", "given": "Shyamprasad N", "initials": "SN", "orcid": "0000-0002-2278-1368", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/58df34262ccf4569b54162cfd38525be.json"}}, {"family": "Herland", "given": "Anna", "initials": "A", "orcid": "0000-0002-5002-2537", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/367ed0d139fe4136808b62ee61baa4f0.json"}}, {"family": "Niklaus", "given": "Frank", "initials": "F", "orcid": "0000-0002-0525-8647", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/cbba7fd047e8468288fc79b7b0275ff3.json"}}, {"family": "Stemme", "given": "G\u00f6ran", "initials": "G", "orcid": "0000-0001-9552-4234", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/122f084eea624e5a801c8fafa6d48f6a.json"}}], "type": "journal article", "published": "2025-02-12", "journal": {"title": "ACS Appl Mater Interfaces", "issn": "1944-8252", "volume": "17", "issue": "6", "pages": "9047-9058", "issn-l": "1944-8244"}, "abstract": "Solid-state nanopores offer unique possibilities for biomolecule sensing; however, scalable production of sub-5 nm pores with precise diameter control remains a manufacturing challenge. In this work, we developed a scalable method to fabricate sub-5 nm nanopores in silicon (Si) nanomembranes through metal-assisted chemical etching (MACE) using gold nanoparticles. Notably, we present a previously unreported self-limiting effect that enables sub-5 nm nanopore formation from both 10 and 40 nm nanoparticles in the 12 nm thick monocrystalline device layer of a silicon-on-insulator substrate. This effect reveals distinctive etching dynamics in ultrathin Si nanomembranes, enabling precise control over nanopore dimensions. The resulting nanopore sensor, suspended over self-aligned spheroidal oxide undercuts with diameters of just a few hundred nanometers, exhibited low electrical noise and high stability due to encapsulation within dielectric layers. In DNA translocation experiments, our nanopore platform could distinguish folded and unfolded DNA conformations and maintained stable baseline conductance for up to 6 h, demonstrating both sensitivity and robustness. Our scalable nanopore fabrication method is compatible with wafer-level and batch processing and holds promise for advancing biomolecular sensing and analysis.", "doi": "10.1021/acsami.4c19750", "pmid": "39882662", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC11826499"}], "notes": [], "created": "2026-08-20T08:08:23.883Z", "modified": "2026-08-20T08:08:23.967Z"}, {"entity": "publication", "iuid": "7d836b85756546f1b18f2851412b8d7e", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/7d836b85756546f1b18f2851412b8d7e.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/7d836b85756546f1b18f2851412b8d7e"}}, "title": "Localized Nanopore Fabrication in Silicon Nitride Membranes by Femtosecond Laser Exposure and Subsequent Controlled Breakdown.", "authors": [{"family": "Leva", "given": "Chrysovalantou V", "initials": "CV"}, {"family": "Jain", "given": "Saumey", "initials": "S", "orcid": "0000-0002-2810-2151", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/969496e3da804b54bea1cf345294433f.json"}}, {"family": "Kistermann", "given": "Kevin", "initials": "K"}, {"family": "Sakurai", "given": "Kasumi", "initials": "K"}, {"family": "Stemme", "given": "G\u00f6ran", "initials": "G", "orcid": "0000-0001-9552-4234", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/122f084eea624e5a801c8fafa6d48f6a.json"}}, {"family": "Herland", "given": "Anna", "initials": "A", "orcid": "0000-0002-5002-2537", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/367ed0d139fe4136808b62ee61baa4f0.json"}}, {"family": "Mayer", "given": "Joachim", "initials": "J", "orcid": "0000-0003-3292-5342", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/6b355f200cc346b389e9dc7901872fe7.json"}}, {"family": "Niklaus", "given": "Frank", "initials": "F", "orcid": "0000-0002-0525-8647", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/cbba7fd047e8468288fc79b7b0275ff3.json"}}, {"family": "Raja", "given": "Shyamprasad N", "initials": "SN", "orcid": "0000-0002-2278-1368", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/58df34262ccf4569b54162cfd38525be.json"}}], "type": "journal article", "published": "2025-02-05", "journal": {"title": "ACS Appl Mater Interfaces", "issn": "1944-8252", "volume": "17", "issue": "5", "pages": "8737-8748", "issn-l": "1944-8244"}, "abstract": "Controlled breakdown has emerged as an effective method for fabricating solid-state nanopores in thin suspended dielectric membranes for various biomolecular sensing applications. On an unpatterned membrane, the site of nanopore formation by controlled breakdown is random. Nanopore formation on a specific site on the membrane has previously been realized using local thinning of the membrane by lithographic processes or laser-assisted photothermal etching under immersion in an aqueous salt solution. However, these approaches require elaborate and expensive cleanroom-based lithography processes or involve intricate procedures using custom-made equipment. Here, we present a rapid cleanroom-free approach using single pulse femtosecond laser exposures of 50 nm thick silicon nitride membranes in air to localize the site of nanopore formation by subsequent controlled breakdown to an area less than 500 nm in diameter on the membrane. The precise positioning of the nanopores on the membrane could be produced both using laser exposure powers which caused significant thinning of the silicon nitride membrane (up to 60% of the original thickness locally), as well as at laser powers which caused no visible modification of the membrane at all. We show that nanopores made using our approach can work as single-molecule sensors by performing dsDNA translocation experiments. Due to the applicability of femtosecond laser processing to a wide range of membrane materials, we expect our approach to simplify the fabrication of localized nanopores by controlled breakdown in a variety of thin film material stacks, thereby enabling more sophisticated nanopore sensors.", "doi": "10.1021/acsami.5c00255", "pmid": "39870574", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC11803561"}], "notes": [], "created": "2026-08-20T08:08:29.746Z", "modified": "2026-08-20T08:08:29.834Z"}, {"entity": "publication", "iuid": "e154fdd25c074698958523cd700c4ae6", "links": {"self": {"href": "https://publications-affiliated.scilifelab.se/publication/e154fdd25c074698958523cd700c4ae6.json"}, "display": {"href": "https://publications-affiliated.scilifelab.se/publication/e154fdd25c074698958523cd700c4ae6"}}, "title": "Electromigrated Gold Nanogap Tunnel Junction Arrays: Fabrication and Electrical Behavior in Liquid and Gaseous Media.", "authors": [{"family": "Raja", "given": "Shyamprasad N", "initials": "SN", "orcid": "0000-0002-2278-1368", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/58df34262ccf4569b54162cfd38525be.json"}}, {"family": "Jain", "given": "Saumey", "initials": "S", "orcid": "0000-0002-2810-2151", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/969496e3da804b54bea1cf345294433f.json"}}, {"family": "Kipen", "given": "Javier", "initials": "J"}, {"family": "Jald\u00e9n", "given": "Joakim", "initials": "J"}, {"family": "Stemme", "given": "G\u00f6ran", "initials": "G", "orcid": "0000-0001-9552-4234", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/122f084eea624e5a801c8fafa6d48f6a.json"}}, {"family": "Herland", "given": "Anna", "initials": "A", "orcid": "0000-0002-5002-2537", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/367ed0d139fe4136808b62ee61baa4f0.json"}}, {"family": "Niklaus", "given": "Frank", "initials": "F", "orcid": "0000-0002-0525-8647", "researcher": {"href": "https://publications-affiliated.scilifelab.se/researcher/cbba7fd047e8468288fc79b7b0275ff3.json"}}], "type": "journal article", "published": "2024-07-17", "journal": {"title": "ACS Appl Mater Interfaces", "issn": "1944-8252", "volume": "16", "issue": "28", "pages": "37131-37146", "issn-l": "1944-8244"}, "abstract": "Tunnel junctions have been suggested as high-throughput electronic single molecule sensors in liquids with several seminal experiments conducted using break junctions with reconfigurable gaps. For practical single molecule sensing applications, arrays of on-chip integrated fixed-gap tunnel junctions that can be built into compact systems are preferable. Fabricating nanogaps by electromigration is one of the most promising approaches to realize on-chip integrated tunnel junction sensors. However, the electrical behavior of fixed-gap tunnel junctions immersed in liquid media has not been systematically studied to date, and the formation of electromigrated nanogap tunnel junctions in liquid media has not yet been demonstrated. In this work, we perform a comparative study of the formation and electrical behavior of arrays of gold nanogap tunnel junctions made by feedback-controlled electromigration immersed in various liquid and gaseous media (deionized water, mesitylene, ethanol, nitrogen, and air). We demonstrate that tunnel junctions can be obtained from microfabricated gold nanoconstrictions inside liquid media. Electromigration of junctions in air produces the highest yield (61-67%), electromigration in deionized water and mesitylene results in a lower yield than in air (44-48%), whereas electromigration in ethanol fails to produce viable tunnel junctions due to interfering electrochemical processes. We map out the stability of the conductance characteristics of the resulting tunnel junctions and identify medium-specific operational conditions that have an impact on the yield of forming stable junctions. Furthermore, we highlight the unique challenges associated with working with arrays of large numbers of tunnel junctions in batches. Our findings will inform future efforts to build single molecule sensors using on-chip integrated tunnel junctions.", "doi": "10.1021/acsami.4c03282", "pmid": "38954436", "labels": [], "xrefs": [{"db": "pmc", "key": "PMC11261569"}], "notes": [], "created": "2026-08-20T08:08:20.105Z", "modified": "2026-08-20T08:08:20.211Z"}]}