title: BODIPY-based azamacrocyclic ensemble for selective fluorescence detection and quantification of homocysteine in biological applications.
abstract: Considering the significant role of plasma homocysteine in physiological processes, two ensembles (F465-Cu(2+) and F508-Cu(2+)) were constructed based on a BODIPY (4,4-difluoro-1,3,5,7-tetramethyl-4-bora-3a,4a-diaza-s-indacene) scaffold conjugated with an azamacrocyclic (1,4,7-triazacyclononane and 1,4,7,10-tetraazacyclododecane) Cu(2+) complex. The results of this effort demonstrated that the F465-Cu(2+) ensemble could be employed to detect homocysteine in the presence of other biologically relevant species, including cysteine and glutathione, under physiological conditions with high selectivity and sensitivity in the turn-on fluorescence mode, while the F508-Cu(2+) ensemble showed no fluorescence responses toward biothiols. A possible mechanism for this homocysteine-specific specificity involving the formation of a homocysteine-induced six-membered ring sandwich structure was proposed and confirmed for the first time by time-dependent fluorescence spectra, ESI-MS and EPR. The detection limit of homocysteine in deproteinized human serum was calculated to be 241.4 nM with a linear range of 0-90.0 μM and the detection limit of F465 for Cu(2+) is 74.7 nM with a linear range of 0-6.0 μM (F508, 80.2 nM, 0-7.0 μM). We have demonstrated the application of the F465-Cu(2+) ensemble for detecting homocysteine in human serum and monitoring the activity of cystathionine β-synthase in vitro.
authors.affiliation: State key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China.
authors.forename: Zan
authors.initials: Z
authors.lastname: Li
authors.affiliation: State key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China. Electronic address: gengzr@nju.edu.cn.
authors.forename: Zhi-Rong
authors.initials: ZR
authors.lastname: Geng
authors.affiliation: State key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China.
authors.forename: Cui
authors.initials: C
authors.lastname: Zhang
authors.affiliation: State key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China.
authors.forename: Xiao-Bo
authors.initials: XB
authors.lastname: Wang
authors.affiliation: State key Laboratory of Coordination Chemistry, School of Chemistry and Chemical Engineering, Collaborative Innovation Center of Advanced Microstructures, Nanjing University, Nanjing 210093, PR China. Electronic address: wangzl@nju.edu.cn.
authors.forename: Zhi-Lin
authors.initials: ZL
authors.lastname: Wang
mesh_terms: D015374:Biosensing Techniques / Q000379:methods; D001896:Boron Compounds / Q000737:chemistry*; D003300:Copper / Q000737:chemistry*; D000080027:Cyclams; D003541:Cystathionine beta-Synthase / Q000378:metabolism; D005456:Fluorescent Dyes / Q000737:chemistry*; D006571:Heterocyclic Compounds / Q000737:chemistry*; D006710:Homocysteine / Q000097:blood* / Q000378:metabolism; D006801:Humans; D057230:Limit of Detection; D013050:Spectrometry, Fluorescence / Q000379:methods
chemical_list: C095489:4,4-difluoro-4-bora-3a,4a-diaza-s-indacene; D001896:Boron Compounds; D000080027:Cyclams; D005456:Fluorescent Dyes; D006571:Heterocyclic Compounds; D006710:Homocysteine; C075712:1,4,7-triazacyclononane; D003300:Copper; C038072:cyclen; D003541:Cystathionine beta-Synthase
keywords: Azamacrocyclic Cu(2+) ensemble; BODIPY; Cystathionine β-synthase activity; Fluorescent chemosensor; Hcy sensor; Homocysteine sensor