Yihan Zhang, Yubing Hu, Zhenkang Zhu, Yunuen Montelongo, Yanting Liu, Shihabuddeen Waqar, Yoon Soo Park, Leon CZ Chan, Nan Jiang and Ali K. Yetisen
{"title":"Holographic hydrogel bandage sensor for continual monitoring of wound healing†","authors":"Yihan Zhang, Yubing Hu, Zhenkang Zhu, Yunuen Montelongo, Yanting Liu, Shihabuddeen Waqar, Yoon Soo Park, Leon CZ Chan, Nan Jiang and Ali K. Yetisen","doi":"10.1039/D5SD00047E","DOIUrl":null,"url":null,"abstract":"<p >Chronic wounds pose serious health and economic challenges. A low calcium (Ca<small><sup>2+</sup></small>) ion concentration during the early stage often indicates infections. Holographic hydrogel sensors offer label-free sensing platforms, providing real-time and continuous detections of analytes upon diffractive wavelength changes detectable by the naked eye or spectrophotometers, improving the Ca<small><sup>2+</sup></small> ion concentration quantification accessibility. Herein, we present a holographic Ca<small><sup>2+</sup></small> ion bandage sensor using carboxylate-containing hydrogels on polydimethylsiloxane (PDMS) substrates for real-time wound-healing assessment through smartphone readout. Simulations are conducted to investigate the effects of mechanical strength on sensitivity. The holographic Ca<small><sup>2+</sup></small> ion sensor replays blueshifts of 35 nm (hue value change of 7) with 0–4 mmol L<small><sup>−1</sup></small> Ca<small><sup>2+</sup></small> ions, changing colors from dark red to red within 7 minutes. It can accurately and stably (over 24 hours) measure Ca<small><sup>2+</sup></small> ions when bent. The stiffness of PDMS was tuned to balance comfort and sensitivity. In point-of-care settings, holographic bandage sensors, comprising the holographic hydrogel sensor, a backing layer, and a dark cotton layer, can continuously monitor Ca<small><sup>2+</sup></small> ions over 10 hours <em>via</em> a smartphone application using hue values. A guiding square in the application assists users in capturing pictures within the inherently narrow viewing angle range of 20–33°. This holographic Ca<small><sup>2+</sup></small> ion bandage sensor facilitates personalized wound assessment through colorimetric interrogation <em>via</em> smartphone readout.</p>","PeriodicalId":74786,"journal":{"name":"Sensors & diagnostics","volume":" 9","pages":" 736-749"},"PeriodicalIF":4.1000,"publicationDate":"2025-07-02","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"https://pubs.rsc.org/en/content/articlepdf/2025/sd/d5sd00047e?page=search","citationCount":"0","resultStr":null,"platform":"Semanticscholar","paperid":null,"PeriodicalName":"Sensors & diagnostics","FirstCategoryId":"1085","ListUrlMain":"https://pubs.rsc.org/en/content/articlelanding/2025/sd/d5sd00047e","RegionNum":0,"RegionCategory":null,"ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":null,"EPubDate":"","PubModel":"","JCR":"Q2","JCRName":"CHEMISTRY, ANALYTICAL","Score":null,"Total":0}
引用次数: 0
Abstract
Chronic wounds pose serious health and economic challenges. A low calcium (Ca2+) ion concentration during the early stage often indicates infections. Holographic hydrogel sensors offer label-free sensing platforms, providing real-time and continuous detections of analytes upon diffractive wavelength changes detectable by the naked eye or spectrophotometers, improving the Ca2+ ion concentration quantification accessibility. Herein, we present a holographic Ca2+ ion bandage sensor using carboxylate-containing hydrogels on polydimethylsiloxane (PDMS) substrates for real-time wound-healing assessment through smartphone readout. Simulations are conducted to investigate the effects of mechanical strength on sensitivity. The holographic Ca2+ ion sensor replays blueshifts of 35 nm (hue value change of 7) with 0–4 mmol L−1 Ca2+ ions, changing colors from dark red to red within 7 minutes. It can accurately and stably (over 24 hours) measure Ca2+ ions when bent. The stiffness of PDMS was tuned to balance comfort and sensitivity. In point-of-care settings, holographic bandage sensors, comprising the holographic hydrogel sensor, a backing layer, and a dark cotton layer, can continuously monitor Ca2+ ions over 10 hours via a smartphone application using hue values. A guiding square in the application assists users in capturing pictures within the inherently narrow viewing angle range of 20–33°. This holographic Ca2+ ion bandage sensor facilitates personalized wound assessment through colorimetric interrogation via smartphone readout.