Cationic Polyfluorenes with Phosphorescent Iridium(III) Complexes for Time‐Resolved Luminescent Biosensing and Fluorescence Lifetime Imaging

The application of a time-resolved photoluminescence technique and fluorescence lifetime imaging microscopy for biosensing and bioimaging based on phosphorescent conjugated polyelectrolytes (PCPEs) containing Ir(III) complexes and polyfluorene units is reported. The specially designed PCPEs form 50 nm nanoparticles with blue fluorescence in aqueous solutions. Electrostatic interaction between the nanoparticles and heparin improves the energy transfer between the polyfluorene units to Ir(III) complex, which lights up the red signal for naked-eye sensing. Good selectivity has been demonstrated for heparin sensing in aqueous solution and serum with quantification ranges of 0–70 μM and 0–5 μM, respectively. The signal-to-noise ratio can be further improved through time-resolved emission spectra, especially when the detection is conducted in complicated environment, e.g., in the presence of fluorescent dyes. In addition to heparin sensing, the PCPEs have also been used for specific labeling of live KB cell membrane with high contrast using both confocal fluorescent cellular imaging and fluorescence lifetime imaging microscopies. This study provides a new perspective for designing promising CPEs for biosensing and bioimaging applications.

[1]  Soo Young Park,et al.  A Phosphorescent Ir(III) Complex for Selective Fluoride Ion Sensing with a High Signal‐to‐Noise Ratio , 2008 .

[2]  Wei Huang,et al.  Butterfly-shaped conjugated oligoelectrolyte/graphene oxide integrated assay for light-up visual detection of heparin. , 2011, Analytical chemistry.

[3]  Wai-Yeung Wong,et al.  A "molecular pivot-hinge" based on the pH-regulated intramolecular switching of Pt-Pt and pi-pi interactions. , 2006, Journal of the American Chemical Society.

[4]  Chunhui Huang,et al.  A nonemissive iridium(III) complex that specifically lights-up the nuclei of living cells. , 2011, Journal of the American Chemical Society.

[5]  Y. Urano,et al.  Development of an Si-rhodamine-based far-red to near-infrared fluorescence probe selective for hypochlorous acid and its applications for biological imaging. , 2011, Journal of the American Chemical Society.

[6]  D. Chiu,et al.  Hybrid semiconducting polymer dot-quantum dot with narrow-band emission, near-infrared fluorescence, and high brightness. , 2012, Journal of the American Chemical Society.

[7]  Hong-Ku Shim,et al.  Cationic conjugated polyelectrolytes-triggered conformational change of molecular beacon aptamer for highly sensitive and selective potassium ion detection. , 2012, Journal of the American Chemical Society.

[8]  J. Werner,et al.  Visualizing Core–Shell Structure in Substituted PPV Oligomer Aggregates Using Fluorescence Lifetime Imaging Microscopy (FLIM) , 2011 .

[9]  J. Lakowicz,et al.  Single-cell fluorescence imaging using metal plasmon-coupled probe 2: single-molecule counting on lifetime image. , 2008, Nano letters.

[10]  C. Chung,et al.  Induced self-assembly and Förster resonance energy transfer studies of alkynylplatinum(II) terpyridine complex through interaction with water-soluble poly(phenylene ethynylene sulfonate) and the proof-of-principle demonstration of this two-component ensemble for selective label-free detection of hum , 2011, Journal of the American Chemical Society.

[11]  Qiang Zhao,et al.  Simple conjugated polymers with on-chain phosphorescent iridium(III) complexes: toward ratiometric chemodosimeters for detecting trace amounts of mercury(II). , 2010, Chemistry.

[12]  Shu Wang,et al.  Water-soluble fluorescent conjugated polymers and their interactions with biomacromolecules for sensitive biosensors. , 2010, Chemical Society reviews.

[13]  Qiang Zhao,et al.  Phosphorescent heavy-metal complexes for bioimaging. , 2011, Chemical Society reviews.

[14]  K. Schanze,et al.  Conjugated polyelectrolytes: Synthesis and applications , 2002 .

[15]  Fuyou Li,et al.  Highly selective phosphorescent chemosensor for fluoride based on an iridium(III) complex containing arylborane units. , 2008, Inorganic chemistry.

[16]  David K Smith,et al.  Self-assembling ligands for multivalent nanoscale heparin binding. , 2011, Angewandte Chemie.

[17]  He-Fang Wang,et al.  Turn-on room temperature phosphorescence assay of heparin with tunable sensitivity and detection window based on target-induced self-assembly of polyethyleneimine capped Mn-doped ZnS quantum dots. , 2011, Analytical chemistry.

[18]  Wai-Yeung Wong,et al.  Heavy metal organometallic electrophosphors derived from multi-component chromophores , 2009 .

[19]  E. Anslyn,et al.  A functional assay for heparin in serum using a designed synthetic receptor. , 2005, Angewandte Chemie.

[20]  Young-Tae Chang,et al.  Discovery of heparin chemosensors through diversity oriented fluorescence library approach. , 2008, Chemical communications.

[21]  Wenli Song,et al.  Water-Soluble Iridium(III)-Containing Conjugated Polyelectrolytes with Weakened Energy Transfer Properties for Multicolor Protein Sensing Applications , 2011 .

[22]  D. Scholz,et al.  Cellular uptake mediated off/on responsive near-infrared fluorescent nanoparticles. , 2011, Journal of the American Chemical Society.

[23]  Jiasheng Wu,et al.  Ratiometric fluorescence sensor based on a pyrene derivative and quantification detection of heparin in aqueous solution and serum. , 2011, Analytical chemistry.

[24]  K. Elenitoba-Johnson,et al.  Conjugated Polyelectrolyte‐Antibody Hybrid Materials for Highly Fluorescent Live Cell‐Imaging , 2012, Advanced materials.

[25]  V. Yam,et al.  NIR-emissive alkynylplatinum(II) terpyridyl complex as a turn-on selective probe for heparin quantification by induced helical self-assembly behaviour. , 2011, Chemistry.

[26]  K. Schanze,et al.  Conjugated polyelectrolytes: synthesis, photophysics, and applications. , 2009, Angewandte Chemie.

[27]  Qiang Zhao,et al.  Rational design of metallophosphors with tunable aggregation-induced phosphorescent emission and their promising applications in time-resolved luminescence assay and targeted luminescence imaging of cancer cells , 2012 .

[28]  C. Che,et al.  Organic triplet excited states of gold(I) complexes with oligo(o- or m-phenyleneethynylene) ligands: conjunction of steady-state and time-resolved spectroscopic studies on exciton delocalization and emission pathways. , 2011, Journal of the American Chemical Society.

[29]  E. Anslyn,et al.  A colorimetric sensing ensemble for heparin. , 2002, Journal of the American Chemical Society.

[30]  Hok-Lai Wong,et al.  Diarylethene-containing cyclometalated platinum(II) complexes: tunable photochromism via metal coordination and rational ligand design. , 2011, Journal of the American Chemical Society.

[31]  D. Chiu,et al.  Ratiometric temperature sensing with semiconducting polymer dots. , 2011, Journal of the American Chemical Society.

[32]  D. Ding,et al.  Conjugated polyelectrolyte-cisplatin complex nanoparticles for simultaneous in vivo imaging and drug tracking. , 2011, Nanoscale.

[33]  B. Liu,et al.  Naked-eye detection and quantification of heparin in serum with a cationic polythiophene. , 2010, Analytical chemistry.

[34]  Qiang Zhao,et al.  Cationic iridium(III) complex containing both triarylboron and carbazole moieties as a ratiometric fluoride probe that utilizes a switchable triplet-singlet emission. , 2010, Chemistry.

[35]  B. Liu,et al.  Conjugated Polyelectrolytes as Light‐Up Macromolecular Probes for Heparin Sensing , 2009 .

[36]  Daoben Zhu,et al.  A Convenient Preparation of Multi‐Spectral Microparticles by Bacteria‐Mediated Assemblies of Conjugated Polymer Nanoparticles for Cell Imaging and Barcoding , 2012, Advanced materials.

[37]  Stanley W Botchway,et al.  Time-resolved and two-photon emission imaging microscopy of live cells with inert platinum complexes , 2008, Proceedings of the National Academy of Sciences.

[38]  Hsien-Chang Chang,et al.  Determination of heparin levels in blood with activated partial thromboplastin time by a piezoelectric quartz crystal sensor , 2001 .

[39]  B. Liu,et al.  Fluorescent Conjugated Polyelectrolytes for Bioimaging , 2011 .

[40]  Bin Liu,et al.  Polymer encapsulated conjugated polymer nanoparticles for fluorescence bioimaging , 2012 .

[41]  Thomas Schneider,et al.  Ultrabright and bioorthogonal labeling of cellular targets using semiconducting polymer dots and click chemistry. , 2010, Angewandte Chemie.

[42]  B. Liu,et al.  Interpolyelectrolyte Complexes of Anionic Water-Soluble Conjugated Polymers and Proteins as Platforms for Multicolor Protein Sensing and Quantification , 2008 .

[43]  Wei Huang,et al.  DNA biosensors based on water-soluble conjugated polymers. , 2011, Biosensors & bioelectronics.

[44]  H. Demir,et al.  Conjugated polymer nanoparticles. , 2010, Nanoscale.

[45]  K. Ohkubo,et al.  Phosphorescent sensor for biological mobile zinc. , 2011, Journal of the American Chemical Society.

[46]  K. K. Lo,et al.  Applications of luminescent inorganic and organometallic transition metal complexes as biomolecular and cellular probes. , 2012, Dalton transactions.

[47]  G. Bazan,et al.  Design and synthesis of monofunctionalized, water-soluble conjugated polymers for biosensing and imaging applications. , 2011, Journal of the American Chemical Society.

[48]  Kenneth Kam-Wing Lo,et al.  Luminescent rhenium(I) polypyridine complexes appended with an α-D-glucose moiety as novel biomolecular and cellular probes. , 2011, Chemistry.

[49]  W. Wong,et al.  A Water-Soluble Organometallic Conjugated Polyelectrolyte for the Direct Colorimetric Detection of Silver Ion in Aqueous Media with High Selectivity and Sensitivity , 2011 .

[50]  J. Olson,et al.  Design of highly emissive polymer dot bioconjugates for in vivo tumor targeting. , 2011, Angewandte Chemie.

[51]  Andreas Winter,et al.  Recent Developments in the Application of Phosphorescent Iridium(III) Complex Systems , 2009 .

[52]  K. Schanze,et al.  Luminescence quenching of a phosphorescent conjugated polyelectrolyte. , 2004, Journal of the American Chemical Society.

[53]  M. Nitz,et al.  Pattern-based recognition of heparin contaminants by an array of self-assembling fluorescent receptors. , 2009, Angewandte Chemie.

[54]  M. Porcionatto,et al.  Heparan sulfates and heparins: similar compounds performing the same functions in vertebrates and invertebrates? , 1999, Brazilian journal of medical and biological research = Revista brasileira de pesquisas medicas e biologicas.

[55]  Deqing Zhang,et al.  The convenient fluorescence turn-on detection of heparin with a silole derivative featuring an ammonium group. , 2008, Chemical communications.

[56]  Fuyou Li,et al.  Phosphorescent chemosensors based on heavy-metal complexes. , 2010, Chemical Society reviews.

[57]  Qiong Yang,et al.  Water-soluble conjugated polymers for imaging, diagnosis, and therapy. , 2012, Chemical reviews.

[58]  B. Liu,et al.  Recent Advances in Conjugated Polyelectrolytes for Emerging Optoelectronic Applications , 2011 .

[59]  T. Schrader,et al.  A fluorescent polymeric heparin sensor. , 2007, Chemistry.

[60]  S. Achilefu,et al.  Fluorescence lifetime measurements and biological imaging. , 2010, Chemical reviews.