{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,7,30]],"date-time":"2026-07-30T09:21:20Z","timestamp":1785403280324,"version":"3.56.0"},"reference-count":50,"publisher":"MDPI AG","issue":"15","license":[{"start":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T00:00:00Z","timestamp":1784851200000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22405234"],"award-info":[{"award-number":["22405234"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001809","name":"National Natural Science Foundation of China","doi-asserted-by":"publisher","award":["22401252"],"award-info":[{"award-number":["22401252"]}],"id":[{"id":"10.13039\/501100001809","id-type":"DOI","asserted-by":"publisher"}]},{"award":["22405234"],"award-info":[{"award-number":["22405234"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]},{"award":["22401252"],"award-info":[{"award-number":["22401252"]}],"id":[{"id":"https:\/\/ror.org\/01h0zpd94","id-type":"ROR","asserted-by":"publisher"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Luminescent sensing in aqueous media using organic small-molecule emitters is often constrained by water-induced fluorescence quenching and indicator leakage. In this study, a polymer-confined thermally activated delayed fluorescence (TADF) material, poly-BrTPPz, was synthesized by covalently copolymerizing a donor\u2013acceptor monomer into a polyacrylamide network. Density functional theory calculations indicate spatial frontier orbital separation. The polymer matrix restricts intramolecular motion, while the polar amide microenvironment provides a solid-state solvation effect, decreasing the reverse intersystem crossing barrier to activate delayed luminescence with a lifetime of 303 \u03bcs and a photoluminescence quantum yield of 69.1% in the solid state. In aqueous environments, the material exhibits a selective quenching response toward iron(III) ions (Fe3+) through a mechanism involving the inner filter effect and pyrazine-coordinated static quenching. To mitigate potential secondary environmental contamination, a transmembrane diffusion model was evaluated by encapsulating the polymer within a semi-permeable membrane, which limits indicator leakage while permitting analyte permeation. This work outlines a design approach for environment-responsive luminescent devices in closed aquatic systems.<\/jats:p>","DOI":"10.3390\/molecules31152575","type":"journal-article","created":{"date-parts":[[2026,7,24]],"date-time":"2026-07-24T07:36:13Z","timestamp":1784878573000},"page":"2575","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Polymer Network-Confined Purely Organic Material with Long-Lived Delayed Emission for Aqueous Iron(III) Ion Sensing"],"prefix":"10.3390","volume":"31","author":[{"ORCID":"https:\/\/orcid.org\/0009-0002-2101-9969","authenticated-orcid":false,"given":"Rao","family":"Luo","sequence":"first","affiliation":[{"name":"Polytechnic Institute of Zhejiang University, Zhejiang University, Hangzhou 310015, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-2882-8753","authenticated-orcid":false,"given":"Xiaohan","family":"Lin","sequence":"additional","affiliation":[{"name":"Polytechnic Institute of Zhejiang University, Zhejiang University, Hangzhou 310015, China"},{"name":"Institute of Zhejiang University\u2014Quzhou, Quzhou 324000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-8529-1799","authenticated-orcid":false,"given":"Chen","family":"Xu","sequence":"additional","affiliation":[{"name":"Polytechnic Institute of Zhejiang University, Zhejiang University, Hangzhou 310015, China"},{"name":"Institute of Zhejiang University\u2014Quzhou, Quzhou 324000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-3048-4678","authenticated-orcid":false,"given":"Shaodong","family":"Zhou","sequence":"additional","affiliation":[{"name":"Polytechnic Institute of Zhejiang University, Zhejiang University, Hangzhou 310015, China"},{"name":"Institute of Zhejiang University\u2014Quzhou, Quzhou 324000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Chao","family":"Qian","sequence":"additional","affiliation":[{"name":"Polytechnic Institute of Zhejiang University, Zhejiang University, Hangzhou 310015, China"},{"name":"Institute of Zhejiang University\u2014Quzhou, Quzhou 324000, China"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2026,7,24]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"e70041","DOI":"10.1002\/rpm2.70041","article-title":"Recent advances in fluorescent materials innovation and film-based sensing application","volume":"4","author":"Gou","year":"2026","journal-title":"Responsive Mater."},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Li, L., Wang, J., Xu, S., Li, C., and Dong, B. 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