{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,8,18]],"date-time":"2026-08-18T14:28:52Z","timestamp":1787063332265,"version":"build-2736575974"},"reference-count":28,"publisher":"MDPI AG","issue":"11","license":[{"start":{"date-parts":[[2025,5,31]],"date-time":"2025-05-31T00:00:00Z","timestamp":1748649600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"Department of Science and Technology\u2014Philippine Council for Health Research and Development (DOST-PCHRD)"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>The pH level of a wound environment is a crucial biomarker for monitoring wound healing, particularly in chronic wounds, where alkalinity (pH &gt; 7) is linked to bacterial colonization and infection. This study developed and optimized a halochromic sensor film composed of polyvinyl alcohol (PVA), polyethylene glycol (PEG), and bromothymol blue (BTB) to enable rapid and reliable pH-responsive color transitions. Feature selection using Principal Component Analysis (PCA) and the ReliefF algorithm identified Hue, Saturation, and a as key features influencing pH responsivity. Optimization of BTB (0.01\u20130.05%) and PEG (6\u201310%) concentrations was conducted using bird-inspired metaheuristic algorithms, including the Parrot Optimizer (PO), Pelican Optimization Algorithm (POA), and Secretary Bird Optimization Algorithm (SBOA). While final fitness values showed negligible variation (188.595647 for GP-PO, 188.595634 for GP-POA, and 188.595634 for GP-SBOA), GP-PO demonstrated superior convergence and stability, efficiently identifying the optimal formulation (0.02% BTB, 6% PEG). The optimized film achieved a complete color transition within 3\u20135 min, a 23.15% reduction compared to the non-optimized formulation. Statistical analysis revealed that BTB concentration significantly affected response time (p = 0.01), while PEG concentration had no significant effect (p &gt; 0.05). These findings highlight the potential of halochromic films for real-time, non-invasive pH monitoring in chronic wounds.<\/jats:p>","DOI":"10.3390\/s25113494","type":"journal-article","created":{"date-parts":[[2025,6,2]],"date-time":"2025-06-02T10:21:49Z","timestamp":1748859709000},"page":"3494","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":3,"title":["Optimization of Dye and Plasticizer Concentrations in Halochromic Sensor Films for Rapid pH Response Using Bird-Inspired Metaheuristic Algorithms"],"prefix":"10.3390","volume":"25","author":[{"ORCID":"https:\/\/orcid.org\/0009-0007-5031-3020","authenticated-orcid":false,"given":"Daeuk","family":"Kim","sequence":"first","affiliation":[{"name":"Department of Manufacturing Engineering and Management, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"},{"name":"Center for Engineering and Sustainable Development Research, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7611-1562","authenticated-orcid":false,"suffix":"II","given":"Ronnie S.","family":"Concepcion","sequence":"additional","affiliation":[{"name":"Department of Manufacturing Engineering and Management, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"},{"name":"Center for Engineering and Sustainable Development Research, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6671-4079","authenticated-orcid":false,"given":"Joseph Rey H.","family":"Sta. Agueda","sequence":"additional","affiliation":[{"name":"Department of Manufacturing Engineering and Management, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"},{"name":"Center for Engineering and Sustainable Development Research, Gokongwei College of Engineering, De La Salle University, Manila 1004, Philippines"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-8541-4362","authenticated-orcid":false,"given":"Jubert C.","family":"Marquez","sequence":"additional","affiliation":[{"name":"Department of Biology, College of Science, De La Salle University, Manila 1004, Philippines"},{"name":"Basic Research Laboratory, Department of Physiology, College of Medicine, Smart Marine Therapeutic Center, Cardiovascular and Metabolic Disease Core Research Support Center, Inje University, Busan 47392, Republic of Korea"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2025,5,31]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2460","DOI":"10.1039\/D4BM00155A","article-title":"Multifunctional Antibacterial Hydrogels for Chronic Wound Management","volume":"12","author":"Hu","year":"2024","journal-title":"Biomater. 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