{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,9,21]],"date-time":"2026-09-21T20:53:42Z","timestamp":1790024022766,"version":"4.0.1"},"reference-count":41,"publisher":"MDPI AG","issue":"10","license":[{"start":{"date-parts":[[2018,10,12]],"date-time":"2018-10-12T00:00:00Z","timestamp":1539302400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Sensors"],"abstract":"<jats:p>Quinoxaline-based novel acid-responsive probe Q1 was designed on the basis of a conjugated donor-acceptor (D-A) subunit. Q1 shows colorimetric and fluorometric changes through protonation and deprotonation in dichloromethane. With the addition of the trifluoroacetic acid (TFA), UV-vis absorption spectral changes in peak intensity of Q1 was observed. Moreover, the appearance of a new peaks at 284 nm 434 nm in absorption spectra with the addition of TFA indicating protonation of quinoxaline nitrogen and form Q1.H+ and Q1.2H+. The emission spectra display appearance of new emission peak at 515 nm. The optical property variations were supported by time resolved fluorescence studies. The energy band gap was calculated by employing cyclic voltammetry and density functional calculations. Upon addition of triethylamine (TEA) the fluorescence emission spectral changes of Q1 are found to be reversible. Q1 shows color changes from blue to green in basic and acidic medium, respectively. The paper strip test was developed for making Q1 a colorimetric and fluorometric indicator.<\/jats:p>","DOI":"10.3390\/s18103433","type":"journal-article","created":{"date-parts":[[2018,10,12]],"date-time":"2018-10-12T10:54:03Z","timestamp":1539341643000},"page":"3433","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":24,"title":["Proton Triggered Colorimetric and Fluorescence Response of a Novel Quinoxaline Compromising a Donor-Acceptor System"],"prefix":"10.3390","volume":"18","author":[{"given":"Yogesh W.","family":"More","sequence":"first","affiliation":[{"name":"Polymers and Functional Material Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sachin D.","family":"Padghan","sequence":"additional","affiliation":[{"name":"Polymers and Functional Material Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rajesh S.","family":"Bhosale","sequence":"additional","affiliation":[{"name":"Polymers and Functional Material Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India"},{"name":"Department of Chemistry, Indrashil University, Kadi, Mehsana 382740, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Rajendra P.","family":"Pawar","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Deogiri College, Aurangabad 431005, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Avinash L.","family":"Puyad","sequence":"additional","affiliation":[{"name":"School of Chemical Sciences, Swami Ramanand Teerth Marathwada University, Nanded 436106, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"given":"Sidhanath V.","family":"Bhosale","sequence":"additional","affiliation":[{"name":"Polymers and Functional Material Division, CSIR-Indian Institute of Chemical Technology, Hyderabad 500 007, India"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0002-4150-2600","authenticated-orcid":false,"given":"Sheshanath V.","family":"Bhosale","sequence":"additional","affiliation":[{"name":"Department of Chemistry, Goa University, Taleigao Plateau Goa 403206, India"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2018,10,12]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"2381","DOI":"10.1242\/jcs.107.9.2381","article-title":"Characterization of very acidic phagosomes in breast cancer cells and their association with invasion","volume":"107","author":"Montcourrier","year":"1994","journal-title":"J. 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