{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,10,23]],"date-time":"2026-10-23T21:11:36Z","timestamp":1792789896821,"version":"4.5.0"},"reference-count":32,"publisher":"MDPI AG","issue":"19","license":[{"start":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T00:00:00Z","timestamp":1790553600000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"name":"State Grid Sichuan Electric Power Company Science and Technology Project","award":["5219Z1250001"],"award-info":[{"award-number":["5219Z1250001"]}],"id":[{"id":"https:\/\/ror.org\/059k2yd77","id-type":"ROR","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>The long-term reliability of converter transformers hinges on the integrity of oil reservoir capsules, whose early-stage oil leakage detection remains challenging. We present Probe (R)-1, a novel D\u2013\u03c0\u2013A solvatochromic fluorescent probe synthesized via a binaphthofuran donor\u2013\u03c0-bridge scaffold functionalized with a p-trifluoromethylbenzoyl acceptor, designed for rapid, visual, on-site identification of trace oil leaks. The probe exhibits a pronounced positive solvatochromic shift of 138 nm across solvent polarity gradients, enabling unambiguous, naked-eye discrimination of structurally similar organic liquids through distinct fluorescence color transitions. In ethanol solutions, the probe achieves an exceptionally low detection limit of 5.88 \u03bcL\/mL for insulating oil, surpassing industry sensitivity requirements. On real-world oil capsule surfaces, the probe produces a stark fluorescence contrast between the oil stains and the capsule background, permitting clear visualization of micro-volume droplets under a 365 nm handheld UV lamp. This method eliminates reliance on complex instrumentation, offering a rapid, cost-effective, and field-deployable solution for proactive maintenance in power grid infrastructure.<\/jats:p>","DOI":"10.3390\/molecules31193459","type":"journal-article","created":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T11:35:59Z","timestamp":1790595359000},"page":"3459","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":0,"title":["Ultra-Solvatochromic Probe Based on Binaphthofuran for Visual Detection of Early Trace Oil Leakage in Oil Reservoir Capsules"],"prefix":"10.3390","volume":"31","author":[{"given":"Yihang","family":"Zhang","sequence":"first","affiliation":[{"name":"State Grid Sichuan Electric Power Company DC Branch, Chengdu 610021, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"}]},{"given":"Hanlin","family":"Wen","sequence":"additional","affiliation":[{"name":"State Grid Sichuan Electric Power Company DC Branch, Chengdu 610021, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"given":"Fuzhi","family":"Li","sequence":"additional","affiliation":[{"name":"State Grid Sichuan Electric Power Company DC Branch, Chengdu 610021, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Xinyuan","family":"Huang","sequence":"additional","affiliation":[{"name":"State Grid Sichuan Electric Power Company DC Branch, Chengdu 610021, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"investigation","vocabulary":"credit"}]},{"given":"Wenqi","family":"Fu","sequence":"additional","affiliation":[{"name":"State Grid Sichuan Electric Power Company DC Branch, Chengdu 610021, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"validation","vocabulary":"credit"},{"role":"formal-analysis","vocabulary":"credit"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-5190-5905","authenticated-orcid":false,"given":"Shanshan","family":"Yu","sequence":"additional","affiliation":[{"name":"Sichuan Houying Electric Power Technology Service Co., Ltd., Deyang 618000, China"}],"role":[{"vocabulary":"crossref","role":"author"},{"role":"conceptualization","vocabulary":"credit"},{"role":"methodology","vocabulary":"credit"},{"role":"resources","vocabulary":"credit"},{"role":"writing-original-draft","vocabulary":"credit"},{"role":"writing-review-editing","vocabulary":"credit"},{"role":"visualization","vocabulary":"credit"},{"role":"supervision","vocabulary":"credit"},{"role":"project-administration","vocabulary":"credit"},{"role":"funding-acquisition","vocabulary":"credit"}]}],"member":"1968","published-online":{"date-parts":[[2026,9,28]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Jin, L., Kim, D., Abu-Siada, A., and Kumar, S. (2022). Oil-Immersed Power Transformer Condition Monitoring Methodologies: A Review. Energies, 15.","DOI":"10.3390\/en15093379"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Li, G., Guo, J., Kang, Y., Huang, Q., Zhao, J., and Liu, C. (2025). Classification and Prevention of Electrical Fires: A Comprehensive Review. Fire, 8.","DOI":"10.3390\/fire8040154"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"014501","DOI":"10.1115\/1.4054143","article-title":"Fire and Explosion Risks and Consequences in Electrical Substations\u2014A Transformer Case Study","volume":"1","year":"2022","journal-title":"ASME Open J. Eng."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"1896","DOI":"10.1016\/j.egyr.2025.08.016","article-title":"Reliability and condition assessment techniques for oil-immersed power equipment under varying temperatures: A review","volume":"14","author":"Ahmed","year":"2025","journal-title":"Energy Rep."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Tan, W., Thio, T.H.G., Siaw, F.L., Li, X., Shen, F., Yang, J., Zou, T., and Jia, Y. (2026). A Lightweight Infrared Thermal Image Recognition Network with Thermal Noise Suppression and Dynamic Feature Fusion for Transformer Oil Leakage Detection. Processes, 14.","DOI":"10.3390\/pr14132175"},{"key":"ref_6","doi-asserted-by":"crossref","unstructured":"Tan, W., Thio, T.H.G., Siaw, F.L., Jia, Y., Li, X., Yang, J., and Li, H. (2026). A Hybrid CNN-SVM for Oil Leakage Detection in Transformer Monitoring. Processes, 14.","DOI":"10.3390\/pr14060970"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"97","DOI":"10.1049\/nde2.12082","article-title":"Traditional Fault Diagnosis Methods for Mineral Oil-immersed Power Transformer Based on Dissolved Gas Analysis: Past, Present and Future","volume":"7","author":"Nanfak","year":"2024","journal-title":"IET Nanodielectr."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"e38558","DOI":"10.1016\/j.heliyon.2024.e38558","article-title":"Research on the Characteristics of Partial Discharge Gas Generation in Typical Defects of Oil Immersed Current Transformers","volume":"10","author":"Feng","year":"2024","journal-title":"Heliyon"},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"1249","DOI":"10.1109\/TDEI.2017.006110","article-title":"A system to detect small amounts of oil leakage with oil visualization for transformers using fluorescence recognition","volume":"24","author":"Lu","year":"2017","journal-title":"IEEE Trans. Dielectr. Electr. Insul."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"7590","DOI":"10.1039\/D3CS00171G","article-title":"Fluorescent probes for targeting the Golgi apparatus: Design strategies and applications","volume":"53","author":"Xu","year":"2024","journal-title":"Chem. Soc. Rev."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"2322","DOI":"10.1039\/D1CS01097B","article-title":"Photoinduced electron transfer (PeT) based fluorescent probes for cellular imaging and disease therapy","volume":"52","author":"Niu","year":"2023","journal-title":"Chem. Soc. Rev."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"218295","DOI":"10.1016\/j.ccr.2026.218295","article-title":"Chelation-based small molecule fluorescent probes for mercury, Lead, cadmium and arsenic: Progress, limitations and future of toxic heavy metal sensing","volume":"567","author":"Samanta","year":"2026","journal-title":"Coord. Chem. Rev."},{"key":"ref_13","doi-asserted-by":"crossref","first-page":"214966","DOI":"10.1016\/j.ccr.2022.214966","article-title":"Recent advancement in graphene quantum dots based fluorescent sensor: Design, construction and bio-medical applications","volume":"478","author":"Li","year":"2023","journal-title":"Coord. Chem. Rev."},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"216894","DOI":"10.1016\/j.ccr.2025.216894","article-title":"Multi-emission fluorescent array sensors based on metal-organic frameworks: Recent research progress in synthesis strategies and applications","volume":"542","author":"Zhang","year":"2025","journal-title":"Coord. Chem. Rev."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"120871","DOI":"10.1016\/j.saa.2022.120871","article-title":"Rapid chiral assay of amino compounds using diethyl squarate","volume":"272","author":"Tian","year":"2022","journal-title":"Spectrochim. Acta Part A"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"3899","DOI":"10.1021\/cr940745l","article-title":"Structural Changes Accompanying Intramolecular Electron Transfer:\u2009Focus on Twisted Intramolecular Charge-Transfer States and Structures","volume":"103","author":"Grabowski","year":"2003","journal-title":"Chem. Rev."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"e202300321","DOI":"10.1002\/tcr.202300321","article-title":"Fluorescent Probes Based on Charge and Proton Transfer for Probing Biomolecular Environment","volume":"24","author":"Pivovarenko","year":"2024","journal-title":"Chem. Rec."},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"12080","DOI":"10.1039\/D3CS01118F","article-title":"Twisted intramolecular charge transfer (TICT) based fluorescent probes and imaging agents","volume":"54","author":"Wu","year":"2025","journal-title":"Chem. Soc. Rev."},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"2415250","DOI":"10.1002\/adfm.202415250","article-title":"Donor\u2013Acceptor Type Solvatochromic Flavonoid Materials Fluorphores for Polarity Sensing and Real-Time Temperature Monitoring","volume":"35","author":"Liu","year":"2025","journal-title":"Adv. Funct. Mater."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"25865","DOI":"10.1002\/anie.202107943","article-title":"A Solvatochromic Fluorescent Probe Reveals Polarity Heterogeneityupon Protein Aggregation in Cells","volume":"60","author":"Wan","year":"2021","journal-title":"Angew. Chem. Int. Ed."},{"key":"ref_21","doi-asserted-by":"crossref","first-page":"148223","DOI":"10.1016\/j.foodchem.2026.148223","article-title":"Rapid on-site quantification of total polar materials in edible oils via a polarity-triggered fluorescent probe and smart 3D-printed sensing platform","volume":"506","author":"Ma","year":"2026","journal-title":"Food Chem."},{"key":"ref_22","doi-asserted-by":"crossref","first-page":"150","DOI":"10.1021\/ar200048d","article-title":"Enantioselective Fluorescent Sensors: A Tale of BINOL","volume":"45","author":"Pu","year":"2012","journal-title":"Acc. Chem. Res."},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"745","DOI":"10.1016\/j.tet.2014.11.007","article-title":"Recent progress on using BINOLs in enantioselective molecular recognition","volume":"71","author":"Yu","year":"2015","journal-title":"Tetrahedron"},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"6769","DOI":"10.1039\/D0AN01225D","article-title":"Recent advances of BINOL-based sensors for enantioselective fluorescence recognition","volume":"145","author":"Yu","year":"2020","journal-title":"Analyst"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"571","DOI":"10.1021\/acs.orglett.4c04175","article-title":"Fluorous-Phase- and Chiral-Axis-Enhanced Fluorescent Sensitivity and Chemoselectivity for Cysteine Recognition","volume":"27","author":"Yang","year":"2025","journal-title":"Org. Lett."},{"key":"ref_26","doi-asserted-by":"crossref","first-page":"141069","DOI":"10.1016\/j.molstruc.2024.141069","article-title":"Synthesis and characterization of a naphthyl-coumarin-based fluorescent probe for the selective recognition of phenylalanine and tyrosine","volume":"1327","author":"Li","year":"2025","journal-title":"J. Mol. Struct."},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"5470","DOI":"10.1002\/chem.202004942","article-title":"Design and Development of Axially Chiral Bis(naphthofuran) Luminogens as Fluorescent Probes for Cell Imaging","volume":"27","author":"Jejurkar","year":"2021","journal-title":"Chem. Eur. J."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"29985","DOI":"10.1039\/C5CP04263A","article-title":"Fluorescence of N-acylated dansylamide with a long hydrophobic tail: Sensitive response to premicellar aggregation of sodium deoxycholate","volume":"17","author":"Tripathi","year":"2015","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"25210","DOI":"10.1039\/C6CP04293G","article-title":"New solvatochromic probes: Performance enhancement via regulation of excited state structures","volume":"18","author":"Liu","year":"2016","journal-title":"Phys. Chem. Chem. Phys."},{"key":"ref_30","doi-asserted-by":"crossref","first-page":"707","DOI":"10.1002\/cjoc.201600732","article-title":"New Fluorescent Conjugates Displaying Solvatochromic Properties","volume":"35","author":"Liu","year":"2017","journal-title":"Chin. J. Chem."},{"key":"ref_31","doi-asserted-by":"crossref","first-page":"2319","DOI":"10.1021\/cr00032a005","article-title":"Solvatochromic Dyes as Solvent Polarity Indicators","volume":"94","author":"Reichardt","year":"1994","journal-title":"Chem. Rev."},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"7258","DOI":"10.1002\/chem.202000423","article-title":"Sulfonation of 3,3\u2032-Diformyl-BINOL for Enantioselective Fluorescent Recognition of Amino Acids in Water","volume":"26","author":"Zhao","year":"2020","journal-title":"Chem. Eur. J."}],"container-title":["Molecules"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/19\/3459\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2026,9,28]],"date-time":"2026-09-28T11:42:56Z","timestamp":1790595776000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1420-3049\/31\/19\/3459"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2026,9,28]]},"references-count":32,"journal-issue":{"issue":"19","published-online":{"date-parts":[[2026,10]]}},"alternative-id":["molecules31193459"],"URL":"https:\/\/doi.org\/10.3390\/molecules31193459","relation":{},"ISSN":["1420-3049"],"issn-type":[{"value":"1420-3049","type":"electronic"}],"subject":[],"published":{"date-parts":[[2026,9,28]]}}}