{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,5,6]],"date-time":"2026-05-06T18:00:21Z","timestamp":1778090421724,"version":"3.51.4"},"reference-count":66,"publisher":"MDPI AG","issue":"22","license":[{"start":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T00:00:00Z","timestamp":1762992000000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"funder":[{"DOI":"10.13039\/501100001871","name":"Portuguese Foundation for Science and Technology","doi-asserted-by":"publisher","award":["UIDB\/00616\/2020"],"award-info":[{"award-number":["UIDB\/00616\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["UIDB\/0079\/2020"],"award-info":[{"award-number":["UIDB\/0079\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100001871","name":"European Regional Development Fund","doi-asserted-by":"publisher","award":["UIDP\/00709\/2020"],"award-info":[{"award-number":["UIDP\/00709\/2020"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"name":"National NMR Network"},{"name":"Infrastructure Project","award":["022161"],"award-info":[{"award-number":["022161"]}]},{"name":"the Fluorescence Microscopy Unit of RISE-Health, UBI"},{"DOI":"10.13039\/501100001871","name":"FCT","doi-asserted-by":"publisher","award":["SFRH\/BD\/141900\/2018"],"award-info":[{"award-number":["SFRH\/BD\/141900\/2018"]}],"id":[{"id":"10.13039\/501100001871","id-type":"DOI","asserted-by":"publisher"}]},{"DOI":"10.13039\/501100000348","name":"the Calouste Gulbenkian Foundation","doi-asserted-by":"crossref","id":[{"id":"10.13039\/501100000348","id-type":"DOI","asserted-by":"crossref"}]}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["IJMS"],"abstract":"<jats:p>Squaraine dyes are a class of organic compounds that exhibit some characteristics inherent to those of an \u201cideal photosensitizer\u201d, such as high absorption at near-infrared-close wavelengths and to produce reactive oxygen species. The introduction of amines into their squaric ring, although known to increase the phototoxicity of squaraines, can improve dyes\u2019 water solubility and induce bathochromic shifts compared to their unsubstituted derivatives, interesting effects in biological contexts. In this work, four new squaraines were synthesized and structurally, photophysically, and photochemically characterized (including absorption and aggregation, fluorescence, light stability, and singlet oxygen generation). Their potential as fluorescent probes for albumin detection was assessed through both in silico and in vitro approaches, as well as their suitability as potential photosensitizers for photodynamic therapy. For this last purpose, the 663 nm light-induced effects of the new dyes were evaluated against the PC-3 prostate cancer cell line, while their photocytotoxicity toward normal human dermal fibroblasts was also assessed using the MTT assay, to determine their potential tumor-selective effects. Low singlet oxygen quantum yields suggest that type I reactions predominate in generating cytotoxicity. Overall, the findings indicate that the designed squaraines exhibit moderate yet favorable interactions with albumin protein while demonstrating selective photodynamic effects toward prostate adenocarcinoma cancer cells, highlighting their potential as protein-assisted, tumor-targeted photosensitizers, providing a basis for further mechanistic studies.<\/jats:p>","DOI":"10.3390\/ijms262210989","type":"journal-article","created":{"date-parts":[[2025,11,13]],"date-time":"2025-11-13T12:57:13Z","timestamp":1763038633000},"page":"10989","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":1,"title":["Fluorescent Albumin-Binding N-Propylbenzene Indolenine-Based Squaraines as Potential Candidates for Prostate Cancer Photodynamic Therapy Photosensitizers"],"prefix":"10.3390","volume":"26","author":[{"ORCID":"https:\/\/orcid.org\/0009-0001-9286-7976","authenticated-orcid":false,"given":"Catarina","family":"Costa","sequence":"first","affiliation":[{"name":"CQ-VR\u2014Chemistry Centre of Vila Real, University of Tr\u00e1s-os-Montes and Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-9402-8949","authenticated-orcid":false,"given":"Eurico","family":"Lima","sequence":"additional","affiliation":[{"name":"CQ-VR\u2014Chemistry Centre of Vila Real, University of Tr\u00e1s-os-Montes and Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal"},{"name":"RISE-Health, Faculty of Health Sciences, University of Beira Interior, Avenida Infante D. Henrique, 6201-506 Covilh\u00e3, Portugal"}]},{"given":"Maria","family":"Vaz","sequence":"additional","affiliation":[{"name":"CQ-VR\u2014Chemistry Centre of Vila Real, University of Tr\u00e1s-os-Montes and Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-6230-4080","authenticated-orcid":false,"given":"Oct\u00e1vio","family":"Ferreira","sequence":"additional","affiliation":[{"name":"RISE-Health, Faculty of Health Sciences, University of Beira Interior, Avenida Infante D. Henrique, 6201-506 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-7256-2622","authenticated-orcid":false,"given":"Renato E.","family":"Boto","sequence":"additional","affiliation":[{"name":"RISE-Health, Faculty of Sciences, University of Beira Interior, Rua Marqu\u00eas d\u2019\u00c1vila e Bolama, 6201-001 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-0110-4795","authenticated-orcid":false,"given":"Paulo","family":"Almeida","sequence":"additional","affiliation":[{"name":"RISE-Health, Faculty of Sciences, University of Beira Interior, Rua Marqu\u00eas d\u2019\u00c1vila e Bolama, 6201-001 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-3300-2606","authenticated-orcid":false,"given":"Jos\u00e9 R.","family":"Fernandes","sequence":"additional","affiliation":[{"name":"CQ-VR\u2014Chemistry Centre of Vila Real, University of Tr\u00e1s-os-Montes and Alto Douro, Quinta de Prados, 5001-801 Vila Real, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-4297-5108","authenticated-orcid":false,"given":"Samuel M.","family":"Silvestre","sequence":"additional","affiliation":[{"name":"RISE-Health, Faculty of Sciences, University of Beira Interior, Rua Marqu\u00eas d\u2019\u00c1vila e Bolama, 6201-001 Covilh\u00e3, Portugal"}]},{"ORCID":"https:\/\/orcid.org\/0000-0001-5654-9359","authenticated-orcid":false,"given":"Lucinda V.","family":"Reis","sequence":"additional","affiliation":[{"name":"RISE-Health, Faculty of Health Sciences, University of Beira Interior, Avenida Infante D. Henrique, 6201-506 Covilh\u00e3, Portugal"}]}],"member":"1968","published-online":{"date-parts":[[2025,11,13]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","unstructured":"Lima, E., and Reis, L.V. (2023). Photodynamic Therapy: From the Basics to the Current Progress of N-Heterocyclic-Bearing Dyes as Effective Photosensitizers. Molecules, 28.","DOI":"10.3390\/molecules28135092"},{"key":"ref_2","doi-asserted-by":"crossref","unstructured":"Correia, J.H., Rodrigues, J.A., Pimenta, S., Dong, T., and Yang, Z. (2021). Photodynamic Therapy Review: Principles, Photosensitizers, Applications, and Future Directions. Pharmaceutics, 13.","DOI":"10.3390\/pharmaceutics13091332"},{"key":"ref_3","doi-asserted-by":"crossref","first-page":"250","DOI":"10.3322\/caac.20114","article-title":"Photodynamic therapy of cancer: An update. CA","volume":"61","author":"Agostinis","year":"2011","journal-title":"Cancer J. Clin."},{"key":"ref_4","doi-asserted-by":"crossref","first-page":"3530","DOI":"10.1021\/acs.molpharmaceut.5c00110","article-title":"Recent Advances in Clinically Used and Trialed Photosensitizers for Antitumor Photodynamic Therapy","volume":"22","author":"Chen","year":"2025","journal-title":"Mol. Pharm."},{"key":"ref_5","doi-asserted-by":"crossref","unstructured":"Janas, K., Boniewska-Bernacka, E., Dyrda, G., and S\u0142ota, R. (2021). Porphyrin and phthalocyanine photosensitizers designed for targeted photodynamic therapy of colorectal cancer. Bioorg. Med. Chem., 30.","DOI":"10.1016\/j.bmc.2020.115926"},{"key":"ref_6","doi-asserted-by":"crossref","first-page":"434","DOI":"10.3390\/photochem4040027","article-title":"Photodynamic Therapy Review: Past, Present, Future, Opportunities and Challenges","volume":"4","author":"Allamyradov","year":"2024","journal-title":"Photochem"},{"key":"ref_7","doi-asserted-by":"crossref","first-page":"115","DOI":"10.1038\/s41392-025-02140-y","article-title":"Phototherapy in cancer treatment: Strategies and challenges","volume":"10","author":"Cai","year":"2025","journal-title":"Signal Transduct. Target. Ther."},{"key":"ref_8","doi-asserted-by":"crossref","first-page":"694","DOI":"10.1002\/anie.196506941","article-title":"Cyclotrimethine Dyes Derived from Squaric Acid","volume":"4","author":"Treibs","year":"1965","journal-title":"Angew. Chem. Int. Ed. Engl."},{"key":"ref_9","doi-asserted-by":"crossref","first-page":"194","DOI":"10.1021\/acs.bioconjchem.9b00482","article-title":"Squaraine Dyes: Molecular Design for Different Applications and Remaining Challenges","volume":"31","author":"Ilina","year":"2020","journal-title":"Bioconjug. Chem."},{"key":"ref_10","doi-asserted-by":"crossref","first-page":"108873","DOI":"10.1016\/j.dyepig.2020.108873","article-title":"Interaction of squaraine dyes with proteins: Looking for more efficient fluorescent turn-on probes","volume":"184","author":"Butnarasu","year":"2021","journal-title":"Dye. Pigment."},{"key":"ref_11","doi-asserted-by":"crossref","first-page":"6589","DOI":"10.1039\/D0NJ00852D","article-title":"A squaraine-based dipicolylamine derivative acting as a turn-on mercury(II) fluorescent probe in water","volume":"44","author":"Esteves","year":"2020","journal-title":"New J. Chem."},{"key":"ref_12","doi-asserted-by":"crossref","first-page":"877","DOI":"10.1007\/s10895-008-0317-2","article-title":"Studies of Benzothiazole and Benzoselenazole Squaraines as Fluorescent Probes for Albumins Detection","volume":"18","author":"Volkova","year":"2008","journal-title":"J. Fluoresc."},{"key":"ref_13","doi-asserted-by":"crossref","unstructured":"Gomes, V.S., Boto, R.E., Almeida, P., Coutinho, P.J., Pereira, M.R., Gon\u00e7alves, M.S.T., and Reis, L.V. (2021). Squaraine dyes as serum albumins probes: Synthesis, photophysical experiments and molecular docking studies. Bioorganic Chem., 115.","DOI":"10.1016\/j.bioorg.2021.105221"},{"key":"ref_14","doi-asserted-by":"crossref","first-page":"2302105","DOI":"10.1002\/adom.202302105","article-title":"Squaraine Dyes for Single-Component Shortwave Infrared-Sensitive Photodiodes and Upconversion Photodetectors","volume":"12","author":"Hu","year":"2024","journal-title":"Adv. Opt. Mater."},{"key":"ref_15","doi-asserted-by":"crossref","first-page":"11063","DOI":"10.1021\/acsami.8b00047","article-title":"Squaraine Dye for a Visibly Transparent All-Organic Optical Upconversion Device with Sensitivity at 1000 nm","volume":"10","author":"Strassel","year":"2018","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_16","doi-asserted-by":"crossref","first-page":"591","DOI":"10.1016\/j.molstruc.2019.05.068","article-title":"Indoline and benzothiazole-based squaraine dye-sensitized solar cells containing bis-pendent sulfonate groups: Synthesis, characterization and solar cell performance","volume":"1195","author":"Asiri","year":"2019","journal-title":"J. Mol. Struct."},{"key":"ref_17","doi-asserted-by":"crossref","first-page":"621","DOI":"10.1002\/cssc.200900077","article-title":"Panchromatic Cross-Substituted Squaraines for Dye-Sensitized Solar Cell Applications","volume":"2","author":"Beverina","year":"2009","journal-title":"ChemSusChem"},{"key":"ref_18","doi-asserted-by":"crossref","first-page":"847","DOI":"10.1039\/C7TC04639A","article-title":"Novel unsymmetrical squaraine-based small molecules for organic solar cells","volume":"6","author":"Chen","year":"2018","journal-title":"J. Mater. Chem. C"},{"key":"ref_19","doi-asserted-by":"crossref","first-page":"113207","DOI":"10.1016\/j.dyepig.2025.113207","article-title":"Squaraine dye: Promising strategies to boost power conversion efficiencies of OPV cells","volume":"245","author":"Irfan","year":"2026","journal-title":"Dye. Pigment."},{"key":"ref_20","doi-asserted-by":"crossref","first-page":"112159","DOI":"10.1016\/j.dyepig.2024.112159","article-title":"A bichromophoric squaraine based NIR fluorescent probe for G-quadruplex in living cells","volume":"227","author":"Rong","year":"2024","journal-title":"Dye. Pigment."},{"key":"ref_21","doi-asserted-by":"crossref","unstructured":"Hao, X., Li, C., Zhao, H., Wei, W., Li, C., Jin, R., Kang, C., and Gao, L. (2023). Synergistic effect of naphthalenediimide and squaraine ligand targeting G-quadruplex DNA in cancer cells. Chem. Biol. Interact., 370.","DOI":"10.1016\/j.cbi.2022.110330"},{"key":"ref_22","doi-asserted-by":"crossref","unstructured":"Chinig\u00f2, G., Pontremoli, C., Bianco, F., Gilardino, A., Moran Plata, M.J., Brossa, A., Bussolati, B., Visentin, S., Barbero, N., and Fiorio Pla, A. (2025). Intracellular calcium-induced ROS generation promotes squaraine phototoxicity. Biochim. Biophys. Acta BBA\u2014Mol. Cell Res., 1872.","DOI":"10.1016\/j.bbamcr.2025.120055"},{"key":"ref_23","doi-asserted-by":"crossref","first-page":"112138","DOI":"10.1016\/j.dyepig.2024.112138","article-title":"Squaraine-containing polymeric nanoparticles enable photodynamic and photothermal therapy of cancer cells","volume":"226","year":"2024","journal-title":"Dye. Pigment."},{"key":"ref_24","doi-asserted-by":"crossref","first-page":"30637","DOI":"10.1021\/acsami.5c03956","article-title":"Smart Type I Squaraine Nano-Photosensitizer Combined with MnO2 for Tumor-Targeted and Ferroptosis-Induced Immunogenic Photodynamic Therapy","volume":"17","author":"Lu","year":"2025","journal-title":"ACS Appl. Mater. Interfaces"},{"key":"ref_25","doi-asserted-by":"crossref","first-page":"117699","DOI":"10.1016\/j.ejmech.2025.117699","article-title":"D-(+)-Biotinylated squaraine dyes: A journey from synthetic conception, photophysical and -chemical characterization, to the exploration of their photoantitumoral action mechanisms","volume":"293","author":"Lima","year":"2025","journal-title":"Eur. J. Med. Chem."},{"key":"ref_26","doi-asserted-by":"crossref","unstructured":"Li, J.-H., You, P.-D., Lu, F., Huang, J.-T., Fu, J.-L., Tang, H.-Y., and Zhou, C.-Q. (2023). Single aromatics sulfonamide substituted dibenzothiazole squaraines for tumor NIR imaging and efficient photodynamic therapy at low drug dose. J. Photochem. Photobiol. B, 240.","DOI":"10.1016\/j.jphotobiol.2023.112653"},{"key":"ref_27","doi-asserted-by":"crossref","first-page":"187","DOI":"10.1016\/j.ejmech.2016.02.035","article-title":"Squaraines bearing halogenated moieties as anticancer photosensitizers: Synthesis, characterization and biological evaluation","volume":"113","author":"Serpe","year":"2016","journal-title":"Eur. J. Med. Chem."},{"key":"ref_28","doi-asserted-by":"crossref","first-page":"101844","DOI":"10.1016\/j.pdpdt.2020.101844","article-title":"In vitro phototherapeutic effects of indolenine-based mono- and dithiosquaraine cyanine dyes against Caco-2 and HepG2 human cancer cell lines","volume":"31","author":"Fernandes","year":"2020","journal-title":"Photodiagnosis Photodyn. Ther."},{"key":"ref_29","doi-asserted-by":"crossref","first-page":"1375","DOI":"10.4155\/fmc-2022-0112","article-title":"\u2018Lights, squaraines, action!\u2019\u2014The role of squaraine dyes in photodynamic therapy","volume":"14","author":"Lima","year":"2022","journal-title":"Future Med. Chem."},{"key":"ref_30","doi-asserted-by":"crossref","unstructured":"Balyan, P., Gupta, S., Mavileti, S.K., Pandey, S.S., and Kato, T. (2024). NIR-Sensitive Squaraine Dye\u2014Peptide Conjugate for Trypsin Fluorogenic Detection. Biosensors, 14.","DOI":"10.3390\/bios14100458"},{"key":"ref_31","doi-asserted-by":"crossref","unstructured":"Gupta, S., Balyan, P., Mavileti, S., Pandey, S., and Kato, T. (2024). Design and Synthesis of Novel Squaraine-Based Fluorescent Probe for Far-Red Detection of Chymotrypsin Enzyme. Molecules, 29.","DOI":"10.3390\/molecules29061282"},{"key":"ref_32","doi-asserted-by":"crossref","first-page":"138226","DOI":"10.1016\/j.molstruc.2024.138226","article-title":"Clarifying the role of carboxyl functionality in squaraines towards aggregation and self-assembly through photophysical characterization and BSA interactions","volume":"1309","author":"Mavileti","year":"2024","journal-title":"J. Mol. Struct."},{"key":"ref_33","doi-asserted-by":"crossref","first-page":"289","DOI":"10.1007\/s44211-024-00697-2","article-title":"Squaraine dye as a fluorescent probe for highly sensitive detection of pyrophosphate and alkaline phosphatase","volume":"41","author":"Zhu","year":"2025","journal-title":"Anal. Sci."},{"key":"ref_34","doi-asserted-by":"crossref","first-page":"170","DOI":"10.1111\/cote.12264","article-title":"Fluorescent amino-substituted squaraine probes for bovine serum albumin","volume":"133","author":"Jurek","year":"2017","journal-title":"Color. Technol."},{"key":"ref_35","doi-asserted-by":"crossref","first-page":"60","DOI":"10.1016\/j.dyepig.2018.01.033","article-title":"An environment-sensitive fluorescent probe for quantification of human serum albumin: Design, sensing mechanism, and its application in clinical diagnosis of hypoalbuminemia","volume":"152","author":"Luo","year":"2018","journal-title":"Dye. Pigment."},{"key":"ref_36","doi-asserted-by":"crossref","first-page":"426","DOI":"10.1016\/j.foodchem.2016.02.026","article-title":"Interaction of glutathione with bovine serum albumin: Spectroscopy and molecular docking","volume":"202","year":"2016","journal-title":"Food Chem."},{"key":"ref_37","doi-asserted-by":"crossref","first-page":"41","DOI":"10.1016\/j.dyepig.2010.11.005","article-title":"Aza-substituted squaraines for the fluorescent detection of albumins","volume":"90","author":"Volkova","year":"2011","journal-title":"Dye. Pigment."},{"key":"ref_38","doi-asserted-by":"crossref","first-page":"552","DOI":"10.1016\/j.saa.2006.03.031","article-title":"Synchronous fluorescence determination of human serum albumin with methyl blue as a fluorescence probe","volume":"66","author":"Hou","year":"2007","journal-title":"Spectrochim. Acta. A Mol. Biomol. Spectrosc."},{"key":"ref_39","doi-asserted-by":"crossref","first-page":"442","DOI":"10.1016\/j.foodchem.2012.09.026","article-title":"Mechanistic and conformational studies on the interaction of food dye amaranth with human serum albumin by multispectroscopic methods","volume":"136","author":"Zhang","year":"2013","journal-title":"Food Chem."},{"key":"ref_40","doi-asserted-by":"crossref","unstructured":"Louren\u00e7o, L.M.O., Beir\u00e3o, S., Melo, A., Fernandes, R., and Tom\u00e9, J.P.C. (2023). Thioglycerol-porphyrin, -chlorin, and -phthalocyanine derivatives for photodynamic therapy of UM-UC-3 bladder cancer cells. J. Photochem. Photobiol. Chem., 442.","DOI":"10.1016\/j.jphotochem.2023.114768"},{"key":"ref_41","doi-asserted-by":"crossref","first-page":"112715","DOI":"10.1016\/j.dyepig.2025.112715","article-title":"Insights into the emissive, theoretical, photobiological, and biomacromolecule-binding properties of new mono-(quinolinyl-triazolyl)-porphyrin hybrid dyes","volume":"238","author":"Diniz","year":"2025","journal-title":"Dye. Pigment."},{"key":"ref_42","doi-asserted-by":"crossref","first-page":"153","DOI":"10.1007\/BF00862734","article-title":"An investigation of squaraines as a new class of fluorophores with long-wavelength excitation and emission","volume":"3","author":"Terpetschnig","year":"1993","journal-title":"J. Fluoresc."},{"key":"ref_43","doi-asserted-by":"crossref","first-page":"108024","DOI":"10.1016\/j.dyepig.2019.108024","article-title":"Photodynamic activity of indolenine-based aminosquaraine cyanine dyes: Synthesis and in vitro photobiological evaluation","volume":"174","author":"Lima","year":"2020","journal-title":"Dye. Pigment."},{"key":"ref_44","doi-asserted-by":"crossref","unstructured":"Martins, T.D., Lima, E., Boto, R.E., Ferreira, D., Fernandes, J.R., Almeida, P., Ferreira, L.F.V., Silva, A.M., and Reis, L.V. (2020). Red and Near-Infrared Absorbing Dicyanomethylene Squaraine Cyanine Dyes: Photophysicochemical Properties and Anti-Tumor Photosensitizing Effects. Materials, 13.","DOI":"10.3390\/ma13092083"},{"key":"ref_45","doi-asserted-by":"crossref","unstructured":"Lima, E., Ferreira, O., Oliveira, J.M., Boto, R.E., Fernandes, J.R., Almeida, P., Silvestre, S.M., Santos, A.O., and Reis, L.V. (2025). \u201cFrom darkness to radiance\u201d: Light-induced type I and II ROS-mediated apoptosis for anticancer effects of dansylpiperazine-bearing squaraine dyes. Bioorganic Chem., 159.","DOI":"10.1016\/j.bioorg.2025.108379"},{"key":"ref_46","doi-asserted-by":"crossref","first-page":"9290","DOI":"10.1039\/D3NR01018J","article-title":"Selection of an aggregation-caused quenching-based fluorescent tracer for imaging studies in nano drug delivery systems","volume":"15","author":"Ji","year":"2023","journal-title":"Nanoscale"},{"key":"ref_47","doi-asserted-by":"crossref","first-page":"e277","DOI":"10.1002\/agt2.277","article-title":"Near-infrared fluorophores with absolute aggregation-caused quenching and negligible fluorescence re-illumination for in vivo bioimaging of nanocarriers","volume":"4","author":"Cai","year":"2023","journal-title":"Aggregate"},{"key":"ref_48","doi-asserted-by":"crossref","unstructured":"Meng, Z., Xue, H., Wang, T., Chen, B., Dong, X., Yang, L., Dai, J., Lou, X., and Xia, F. (2022). Aggregation-induced emission photosensitizer-based photodynamic therapy in cancer: From chemical to clinical. J. Nanobiotechnol., 20.","DOI":"10.1186\/s12951-022-01553-z"},{"key":"ref_49","doi-asserted-by":"crossref","unstructured":"Gomes, V.S.D., Gon\u00e7alves, H.M.R., Boto, R.E.F., Almeida, P., and Reis, L.V. (2020). Barbiturate squaraine dyes as fluorescent probes for serum albumins detection. J. Photochem. Photobiol. Chem., 400.","DOI":"10.1016\/j.jphotochem.2020.112710"},{"key":"ref_50","doi-asserted-by":"crossref","unstructured":"Sousa, M.A., Lima, E., Ferreira, O., Boto, R.E., Almeida, P., and Reis, L.V. (2022). In Vitro and In Silico Evaluation of Indole-Bearing Squaraine Dyes as Potential Human Serum Albumin Fluorescent Probes. Chemosensors, 10.","DOI":"10.3390\/chemosensors10080314"},{"key":"ref_51","doi-asserted-by":"crossref","first-page":"41991","DOI":"10.1039\/C6RA05820E","article-title":"Modulation of singlet oxygen generation in halogenated BODIPY dyes by substitution at their meso position: Towards a solvent-independent standard in the vis region","volume":"6","author":"Arbeloa","year":"2016","journal-title":"RSC Adv."},{"key":"ref_52","doi-asserted-by":"crossref","unstructured":"Cui, S., Guo, X., Wang, S., Wei, Z., Huang, D., Zhang, X., Zhu, T.C., and Huang, Z. (2024). Singlet Oxygen in Photodynamic Therapy. Pharmaceuticals, 17.","DOI":"10.3390\/ph17101274"},{"key":"ref_53","doi-asserted-by":"crossref","first-page":"111239","DOI":"10.1016\/j.dyepig.2023.111239","article-title":"Benz[e]indole-bearing aminosquaraine dyes: Which of the amines introduced into the squaric ring will be able to induce the best in vitro photodynamic effect?","volume":"215","author":"Lima","year":"2023","journal-title":"Dye. Pigment."},{"key":"ref_54","doi-asserted-by":"crossref","first-page":"4600","DOI":"10.1039\/D3TB00545C","article-title":"Recent advances in type I organic photosensitizers for efficient photodynamic therapy for overcoming tumor hypoxia","volume":"11","author":"Lu","year":"2023","journal-title":"J. Mater. Chem. B"},{"key":"ref_55","doi-asserted-by":"crossref","first-page":"2501911","DOI":"10.1002\/smll.202501911","article-title":"Recent Progress of Molecular Design in Organic Type I Photosensitizers","volume":"21","author":"Xiong","year":"2025","journal-title":"Small"},{"key":"ref_56","doi-asserted-by":"crossref","first-page":"2006742","DOI":"10.1002\/smll.202006742","article-title":"Type I Photosensitizers Revitalizing Photodynamic Oncotherapy","volume":"17","author":"Chen","year":"2021","journal-title":"Small"},{"key":"ref_57","doi-asserted-by":"crossref","first-page":"824","DOI":"10.1016\/j.freeradbiomed.2011.05.023","article-title":"Major determinants of photoinduced cell death: Subcellular localization versus photosensitization efficiency","volume":"51","author":"Oliveira","year":"2011","journal-title":"Free Radic. Biol. Med."},{"key":"ref_58","doi-asserted-by":"crossref","first-page":"995","DOI":"10.1039\/b705853e","article-title":"Singlet oxygen quantum yields of potential porphyrin-based photosensitisers for photodynamic therapy","volume":"6","author":"Mathai","year":"2007","journal-title":"Photochem. Photobiol. Sci."},{"key":"ref_59","doi-asserted-by":"crossref","unstructured":"Costa, L.D., Vieira, C., Mesquita, M.Q., Hackbarth, S., Neves, M.G.P.M.S., Almeida, A., Tom\u00e9, A.C., and Faustino, M.A.F. (2025). Quinolinium-substituted porphyrins as promising antimicrobial photosensitizers. J. Photochem. Photobiol. B, 272.","DOI":"10.1016\/j.jphotobiol.2025.113275"},{"key":"ref_60","doi-asserted-by":"crossref","first-page":"2410992","DOI":"10.1002\/adma.202410992","article-title":"Heterodimeric Photosensitizer as Radical Generators to Promoting Type I Photodynamic Conversion for Hypoxic Tumor Therapy","volume":"37","author":"Xiong","year":"2025","journal-title":"Adv. Mater."},{"key":"ref_61","doi-asserted-by":"crossref","first-page":"e202506412","DOI":"10.1002\/ange.202506412","article-title":"A Hypoxia-Triggered Bioreduction of Hydrophilic Type I Photosensitizer for Switchable In Vivo Photoacoustic Imaging and High-Specificity Cancer Phototherapy","volume":"137","author":"Zhao","year":"2025","journal-title":"Angew. Chem."},{"key":"ref_62","doi-asserted-by":"crossref","unstructured":"Wang, Y., Mu, T., Li, X., Zheng, X., Sha, J., Yu, Z., Qin, Y., Ren, H., Wang, Y., and Liu, W. (2025). Hydroxyl-tunable type I photosensitizer based on curcumin for photodynamic therapy against hypoxic tumor cells. J. Photochem. Photobiol. B, 269.","DOI":"10.1016\/j.jphotobiol.2025.113189"},{"key":"ref_63","doi-asserted-by":"crossref","first-page":"128264","DOI":"10.1016\/j.molstruc.2020.128264","article-title":"Binding properties of pyrene-porphyrin dyad to G-quadruplexes in the presence of K+ and Na+ ion and their effect on stability","volume":"1215","author":"Han","year":"2020","journal-title":"J. Mol. Struct."},{"key":"ref_64","doi-asserted-by":"crossref","first-page":"11698","DOI":"10.1039\/c3cc46744a","article-title":"Pyrene-imidazolium complexed graphene for the selective fluorescent detection of G-quadruplex forming DNA","volume":"49","author":"Moon","year":"2013","journal-title":"Chem. Commun."},{"key":"ref_65","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/j.dyepig.2017.05.045","article-title":"G-quadruplex DNA fluorescence sensing by a bis-amine-substituted styrylquinolinium dye","volume":"145","author":"Wang","year":"2017","journal-title":"Dye. Pigment."},{"key":"ref_66","doi-asserted-by":"crossref","unstructured":"Saha, A., Bombard, S., Granzhan, A., and Teulade-Fichou, M.-P. (2018). Probing of G-Quadruplex Structures via Ligand-Sensitized Photochemical Reactions in BrU-Substituted DNA. Sci. Rep., 8.","DOI":"10.1038\/s41598-018-34141-z"}],"container-title":["International Journal of Molecular Sciences"],"original-title":[],"language":"en","link":[{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/22\/10989\/pdf","content-type":"unspecified","content-version":"vor","intended-application":"similarity-checking"}],"deposited":{"date-parts":[[2025,11,15]],"date-time":"2025-11-15T05:26:10Z","timestamp":1763184370000},"score":1,"resource":{"primary":{"URL":"https:\/\/www.mdpi.com\/1422-0067\/26\/22\/10989"}},"subtitle":[],"short-title":[],"issued":{"date-parts":[[2025,11,13]]},"references-count":66,"journal-issue":{"issue":"22","published-online":{"date-parts":[[2025,11]]}},"alternative-id":["ijms262210989"],"URL":"https:\/\/doi.org\/10.3390\/ijms262210989","relation":{},"ISSN":["1422-0067"],"issn-type":[{"value":"1422-0067","type":"electronic"}],"subject":[],"published":{"date-parts":[[2025,11,13]]}}}