{"status":"ok","message-type":"work","message-version":"1.0.0","message":{"indexed":{"date-parts":[[2026,6,10]],"date-time":"2026-06-10T21:37:05Z","timestamp":1781127425433,"version":"3.54.1"},"reference-count":57,"publisher":"MDPI AG","issue":"23","license":[{"start":{"date-parts":[[2019,12,1]],"date-time":"2019-12-01T00:00:00Z","timestamp":1575158400000},"content-version":"vor","delay-in-days":0,"URL":"https:\/\/creativecommons.org\/licenses\/by\/4.0\/"}],"content-domain":{"domain":[],"crossmark-restriction":false},"short-container-title":["Molecules"],"abstract":"<jats:p>Switchable luminescent bioprobes whose emission can be turned on as a function of specific enzymatic activity are emerging as important tools in chemical biology. We report a promising platform for the development of label-free and continuous enzymatic assays in high-throughput mode based on the reversible solvent-induced self-assembly of a neutral dinuclear Pt(II) complex. To demonstrate the utility of this strategy, the switchable luminescence of a dinuclear Pt(II) complex was utilized in developing an experimentally simple, fast (10 min), low cost, and label-free turn-on luminescence assay for the endonuclease enzyme DNAse I. The complex displays a near-IR (NIR) aggregation-induced emission at 785 nm in aqueous solution that is completely quenched upon binding to G-quadruplex DNA from the human c-myc oncogene. Luminescence is restored upon DNA degradation elicited by exposure to DNAse I. Correlation between near-IR luminescence intensity and DNAse I concentration in human serum samples allows for fast and label-free detection of DNAse I down to 0.002 U\/mL. The Pt(II) complex\/DNA assembly is also effective for identification of DNAse I inhibitors, and assays can be performed in multiwell plates compatible with high-throughput screening. The combination of sensitivity, speed, convenience, and cost render this method superior to all other reported luminescence-based DNAse I assays. The versatile response of the Pt(II) complex to DNA structures promises broad potential applications in developing real-time and label-free assays for other nucleases as well as enzymes that regulate DNA topology.<\/jats:p>","DOI":"10.3390\/molecules24234390","type":"journal-article","created":{"date-parts":[[2019,12,2]],"date-time":"2019-12-02T10:50:45Z","timestamp":1575283845000},"page":"4390","update-policy":"https:\/\/doi.org\/10.3390\/mdpi_crossmark_policy","source":"Crossref","is-referenced-by-count":11,"title":["Expanding the Toolbox for Label-Free Enzyme Assays: A Dinuclear Platinum(II) Complex\/DNA Ensemble with Switchable Near-IR Emission"],"prefix":"10.3390","volume":"24","author":[{"ORCID":"https:\/\/orcid.org\/0000-0001-9074-3331","authenticated-orcid":false,"given":"Moustafa T.","family":"Gabr","sequence":"first","affiliation":[{"name":"Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]},{"ORCID":"https:\/\/orcid.org\/0000-0003-2700-7141","authenticated-orcid":false,"given":"F. Christopher","family":"Pigge","sequence":"additional","affiliation":[{"name":"Department of Chemistry, University of Iowa, Iowa City, IA 52242, USA"}],"role":[{"vocabulary":"crossref","role":"author"}]}],"member":"1968","published-online":{"date-parts":[[2019,12,1]]},"reference":[{"key":"ref_1","doi-asserted-by":"crossref","first-page":"142","DOI":"10.1021\/cb700248m","article-title":"Bright ideas for chemical biology","volume":"3","author":"Lavis","year":"2008","journal-title":"ACS Chem. Biol."},{"key":"ref_2","doi-asserted-by":"crossref","first-page":"1","DOI":"10.1016\/B978-0-12-386932-6.00001-6","article-title":"The chemistry of small-molecule fluorogenic probes","volume":"113","author":"Grimm","year":"2013","journal-title":"Prog. Mol. Biol. Transl. 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