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 human serum albumin.
The interaction of conjugated polyelectrolyte, PPE-SO(3)(-), with platinum(II) complexes, [Pt(tpy)(C≡CC(6)H(4)-CH(2)NMe(3)-4)](OTf)(2) (1) and [Pt(tpy)(C≡C-CH(2)NMe(3))](OTf)(2) (2), has been studied by UV-vis, and steady-state and time-resolved emission spectroscopy. A unique FRET from PPE-SO(3)(-) to the aggregated complex 1 on the polymer chain with Pt···Pt interaction has been demonstrated, resulting in the growth of triplet metal-metal-to-ligand charge transfer ((3)MMLCT) emission in the near-infrared (NIR) region. This two-component ensemble has been employed in a "proof-of-principle" concept for the sensitive and selective label-free detection of human serum albumin (HSA) by the emission spectral changes in the visible and in the NIR region. The spectral changes have been ascribed to the disassembly of the polymer-metal complex aggregates upon the binding of PPE-SO(3)(-) to HSA, which is rich in arginine residues and hydrophobic patches, leading to the decrease in FRET from PPE-SO(3)(-) to the aggregated platinum(II) complex. The ensemble is found to have high selectivity toward HSA over a number of polyelectrolytes, proteins and small amino acids. This has been suggested to be a result of the extra stabilization gained from the Pt···Pt and π-π interactions in addition to the electrostatic and hydrophobic interactions found in the polymer-metal complex aggregates.
Institute of Molecular Functional Materials and Department of Chemistry, The University of Hong Kong, Pokfulam Road, Hong Kong, P.R. China.
Clive Yik-Sham
CY
Chung
Vivian Wing-Wah
VW
Yam
D000476:Alkanesulfonates / Q000737:chemistry*; D000480:Alkynes / Q000737:chemistry*; D004987:Ethers / Q000737:chemistry*; D031541:Fluorescence Resonance Energy Transfer; D006801:Humans; D015394:Molecular Structure; D009942:Organometallic Compounds / Q000737:chemistry*; D010984:Platinum / Q000737:chemistry*; D011725:Pyridines / Q000737:chemistry*; D012709:Serum Albumin / Q000032:analysis* / Q000737:chemistry; D012995:Solubility; D013194:Staining and Labeling; D014867:Water / Q000737:chemistry*
D000476:Alkanesulfonates; D000480:Alkynes; D004987:Ethers; D009942:Organometallic Compounds; D011725:Pyridines; D012709:Serum Albumin; C436384:phenyleneethynylene; D014867:Water; D010984:Platinum