[{"data":1,"prerenderedAt":-1},["ShallowReactive",2],{"detail-sidebar-cat-0-en-105":3,"doc-seo-462881-105":59,"doc-detail-462881-en":130},{"code":4,"msg":5,"data":6},0,"success",[7,13,18,23,28,33,38,43,48,51,55],{"id":8,"doc_module":4,"doc_module_name":9,"category_name":10,"show_sort_weight":11,"slug":12},1,"Document","Story & Novel",90,"story-novel",{"id":14,"doc_module":4,"doc_module_name":9,"category_name":15,"show_sort_weight":16,"slug":17},2,"Literature",80,"literature",{"id":19,"doc_module":4,"doc_module_name":9,"category_name":20,"show_sort_weight":21,"slug":22},4,"Exam",70,"exam",{"id":24,"doc_module":4,"doc_module_name":9,"category_name":25,"show_sort_weight":26,"slug":27},5,"Comic",60,"comic",{"id":29,"doc_module":4,"doc_module_name":9,"category_name":30,"show_sort_weight":31,"slug":32},6,"Technology",50,"technology",{"id":34,"doc_module":4,"doc_module_name":9,"category_name":35,"show_sort_weight":36,"slug":37},7,"Healthcare",40,"healthcare",{"id":39,"doc_module":4,"doc_module_name":9,"category_name":40,"show_sort_weight":41,"slug":42},8,"Research & Report",30,"research-report",{"id":44,"doc_module":4,"doc_module_name":9,"category_name":45,"show_sort_weight":46,"slug":47},9,"Religion & Spirituality",20,"religion-spirituality",{"id":46,"doc_module":4,"doc_module_name":9,"category_name":49,"show_sort_weight":46,"slug":50},"World Cup","world-cup",{"id":52,"doc_module":4,"doc_module_name":9,"category_name":53,"show_sort_weight":52,"slug":54},10,"Lifestyle","lifestyle",{"id":56,"doc_module":4,"doc_module_name":9,"category_name":57,"show_sort_weight":24,"slug":58},19,"General","general",{"code":4,"msg":60,"data":61},"ok",{"site_id":62,"language":63,"slug":64,"title":65,"keywords":66,"description":67,"schema_data":68,"social_meta":123,"head_meta":125,"extra_data":127,"updated_unix":129},105,"en","psa-responsive-aptamer-based-switchable-aggregates-of-ultrasmall-gold-nanoparticles","PSA-Responsive Aptamer-Based Switchable Aggregates of Ultrasmall Gold Nanoparticles","","Prostate-specific antigen (PSA) is a key biomarker for early detection of prostate cancer recurrence after surgery. This study presents a PSA-responsive aptamer-based switchable aggregate system, AS2-US-AuNP-Aggregate, made from ultrasmall gold nanoparticles linked by (partially) pairing oligomers that selectively disassemble upon PSA binding. The system is optimised using an in silico routine and evaluated for enhanced detection and in vivo applicability. Dynamic light scattering and extinction spectra show PSA-dependent responses down to 10 fM in buffers and 1 pM in filtered plasma, supporting user-friendly diagnostic tools and in vivo development.",{"@graph":69,"@context":122},[70,84,105],{"@type":71,"itemListElement":72},"BreadcrumbList",[73,77,79,82],{"item":74,"name":75,"@type":76,"position":8},"https://docshare.wps.com","Home","ListItem",{"item":78,"name":9,"@type":76,"position":14},"https://docshare.wps.com/document/",{"item":80,"name":35,"@type":76,"position":81},"https://docshare.wps.com/document/healthcare/",3,{"item":83,"name":65,"@type":76,"position":19},"https://docshare.wps.com/document/psa-responsive-aptamer-based-switchable-aggregates-of-ultrasmall-gold-nanoparticles/462881/",{"url":83,"name":65,"@type":85,"image":86,"author":91,"headline":65,"publisher":94,"fileFormat":97,"inLanguage":63,"description":67,"dateModified":98,"datePublished":99,"encodingFormat":97,"isAccessibleForFree":100,"interactionStatistic":101},"DigitalDocument",{"url":87,"@type":88,"width":89,"height":90},"https://docshare.wps.com/thumbnails/psa-responsive-aptamer-based-switchable-aggregates-of-ultrasmall-gold-nanoparticles/462881.png","ImageObject",300,407,{"name":92,"@type":93},"Kurz","Person",{"url":74,"name":95,"@type":96},"DocShare","Organization","application/pdf","2026-11-08","2026-09-30",true,{"@type":102,"interactionType":103,"userInteractionCount":24},"InteractionCounter",{"@type":104},"ViewAction",{"@type":106,"mainEntity":107},"FAQPage",[108,114,118],{"name":109,"@type":110,"acceptedAnswer":111},"What is the purpose of the PSA-responsive AS2-US-AuNP-Aggregate system?","Question",{"text":112,"@type":113},"It is designed to selectively disassemble in the presence of PSA, enabling enhanced detection performance for diagnostic applications after prostate cancer surgery.","Answer",{"name":115,"@type":110,"acceptedAnswer":116},"How are the nanosystems characterized in the study?",{"text":117,"@type":113},"Their sizes and optical properties are measured using dynamic light scattering (DLS) and extinction spectra, including conditions with PSA in buffers and under blood-mimicking conditions.",{"name":119,"@type":110,"acceptedAnswer":120},"What PSA detection limits are reported?",{"text":121,"@type":113},"Responses are reported down to 10 fM PSA in simple buffers and to 1 pM PSA in filtered plasma.","https://schema.org",{"og:url":83,"og:type":124,"og:title":65,"og:site_name":95,"og:description":67},"article",{"robots":126,"canonical":83},"index,follow",{"doc_id":128,"site_id":62},462881,1791112231,{"code":4,"msg":5,"data":131},{"doc_id":128,"user_id":132,"nickname":92,"user_avatar":133,"doc_module":4,"category_id":34,"category_name":35,"doc_title":65,"doc_description":67,"doc_content":134,"file_id":135,"file_url":136,"file_type":137,"file_size":138,"view_count":24,"is_deleted":4,"is_public":8,"is_downloadable":8,"audit_status":8,"page_count":139,"language":140,"language_code":63,"site_id":62,"html_lang":63,"table_of_contents":141,"faqs":142,"seo_title":143,"seo_description":67,"update_tm":144,"read_time":145,"preview_page_count":4},2336478945635,"https://ap-avatar.wpscdn.com/davatar_6f874abed73319feea01a86fa6f0fab8","Article  \nPSA-Responsive Aptamer-Based Switchable Aggregates of Ultrasmall Gold Nanoparticles  \nGiulia Matteoli 1,2,3, *, Pasquale Mastella 1,2, Elisa Ottalagana 1,2, Riccardo Nifosì 1,4, Luca Bellucci 1,4, Fabio Beltram 1,2,4 Giovanni Signore 2,5 and Stefano Luin 1,4, *  \nAcademic Editor: Alfredo de la Escosura-Muñiz  \nReceived: 3 November 2025  \nRevised: 11 December 2025  \nAccepted: 17 December 2025  \nPublished: 20 December 2025  \nCopyright: © 2025 by the authors. Licensee MDPI, Basel, Switzerland. This article is an open access article distributed under the terms and conditions of the Creative Commons Attribution (CC BY) license.  \n1 NEST Laboratory, Scuola Normale Superiore, Piazza San Silvestro 12, 56127 Pisa, PI, Italy; [pasquale.mastella@sns.it](pasquale.mastella@sns.it) (P.M.); [elisa.ottalagana@sns.it](elisa.ottalagana@sns.it) (E.O.); [riccardo.nifosi@nano.cnr.it](riccardo.nifosi@nano.cnr.it) (R.N.); [luca.bellucci@nano.cnr.it](luca.bellucci@nano.cnr.it) (L.B.); [fabio.beltram@sns.it](fabio.beltram@sns.it) (F.B.)  \n2 Fondazione Pisana per la Scienza ONLUS, Via Ferruccio Giovannini 13, 56017 San Giuliano Terme, PI, Italy; [giovanni.signore@unipi.it](giovanni.signore@unipi.it)  \n3 Present Address: Institute of Clinical Physiology-Italian National Research Council, Via Giuseppe Moruzzi 1, 56124 Pisa, PI, Italy  \n4 NEST, Istituto Nanoscienze-CNR, Piazza S. Silvestro 12, 56127 Pisa, PI, Italy  \n5 Biochemistry Unit, Department of Biology, University of Pisa, via san Zeno 51, 56123 Pisa, PI, Italy  \n* Correspondence: [giuliamatteoli@cnr.it](giuliamatteoli@cnr.it) (G.M.); [s.luin@sns.it](s.luin@sns.it) (S.L.)  \nAbstract  \nProstate-specific antigen (PSA) is a key biomarker for the early detection of prostate cancer recurrence following surgical treatment. In this study, we present a PSA-responsive, aptamer-based switchable aggregate system, named AS2-US-AuNP-Aggregate, composed of ultrasmall gold nanoparticles (US-AuNPs) linked by (partially) pairing oligomers that selectively disassemble in the presence of PSA. The system was optimised also using a previously developed in silico routine and is designed for enhanced detection capabilities and for supporting in vivo applicability. We measured the sizes of the nanosystems by dynamic light scattering (DLS) and their extinction spectra, also in the presence of PSA in simple buffers, in the presence of DNaseI, and under blood-mimicking conditions (filtered plasma), obtaining a response down to 10 fM PSA in buffers and to 1 pM in filtered plasma. Our findings highlight the potential of aptamer-based nanoparticle aggregates as a basis for user-friendly diagnostic tools. Additionally, we discuss key optimisation strategies to further advance their development for in vivo diagnostic applications.  \nKeywords: prostate cancer; nanoparticles; aptamers; cancer diagnostics; responsive nanosystems; dynamic light scattering (DLS)  \n1. Introduction  \nProstate cancer (PCa) is the second most diagnosed cancer in men, with approximately 1.4 million new cases per year [1] . One possible treatment for PCa is radical prostatectomy (RP), a surgical procedure involving the complete removal of prostate tissue. Following RP, the prostate-specific antigen (PSA) serum level is monitored over time to detect disease relapse. PSA is a secreted protein with a molecular weight of 33 kDa, expressed in both normal and cancerous prostatic tissue, and should not be present in blood after total prostate resection. However, the presence of residual tumour margins after surgery can lead to a cancer relapse with a progressive increase in serum PSA level. A biochemical recurrence (BCR) occurs when PSA levels rise above 0.2 ng/mL (6 pM, the current critical threshold) in two consecutive measurements, and this is highly indicative of tumour relapse. Using  \nthis threshold (defined also as nadir point [2]), approximately 23% of patients experience BCR within five years after surgery.  \nThe development of novel ultrasensit","cbCaisfhAnxf9ltO","https://ap.wps.com/l/cbCaisfhAnxf9ltO","pdf",1245016,21,"English","# Introduction\n## Prostate cancer, PSA monitoring, and biochemical recurrence threshold\n## Limits of current ultrasensitive assays and point-of-care PSA tests\n## Triggerable in vivo nanostructured systems with ex vivo readout","[{\"question\":\"What is the purpose of the PSA-responsive AS2-US-AuNP-Aggregate system?\",\"answer\":\"It is designed to selectively disassemble in the presence of PSA, enabling enhanced detection performance for diagnostic applications after prostate cancer surgery.\"},{\"question\":\"How are the nanosystems characterized in the study?\",\"answer\":\"Their sizes and optical properties are measured using dynamic light scattering (DLS) and extinction spectra, including conditions with PSA in buffers and under blood-mimicking conditions.\"},{\"question\":\"What PSA detection limits are reported?\",\"answer\":\"Responses are reported down to 10 fM PSA in simple buffers and to 1 pM PSA in filtered plasma.\"}]","PSA-Responsive Aptamer-Based Switchable Aggregates of Ultrasmall Gold Nanoparticles | PDF",1790765624,53]