Multiplex Charge-Transfer Interactions between Quantum Dots and Peptide-Bridged Ruthenium Complexes
详细信息 查看全文
- 作者：Igor L. Medintz ; Dorothy Farrell ; Kimihiro Susumu ; Scott A. Trammell ; Jeffrey R. Deschamps ; Florence M. Brunel ; Philip E. Dawson ; Hedi Mattoussi
- 刊名：Analytical Chemistry
- 出版年：2009
- 出版时间：June 15, 2009
- 年：2009
- 卷：81
- 期：12
- 页码：4831-4839
- 全文大小：616K
- 年卷期：v.81,no.12(June 15, 2009)
- ISSN：1520-6882
文摘
Simultaneous detection of multiple independent fluorescent signals or signal multiplexing has the potential to significantly improve bioassay throughput and to allow visualization of concurrent cellular events. Applications based on signal multiplexing, however, remain hard to achieve in practice due to difficulties in both implementing hardware and the photophysical liabilities associated with available organic dye and protein fluorophores. Here, we used charge-transfer interactions between luminescent semiconductor quantum dots (QDs) and proximal redox complexes to demonstrate controlled quenching of QD photoemission in a multiplexed format. In particular, we show that, because of the ability of the Ru complex to effectively interact with CdSe−ZnS QDs emitting over a broad window of the optical spectrum, higher orders of multiplexed quenching can be achieved in a relatively facile manner. Polyhistidine-appended peptides were site-specifically labeled with a redox-active ruthenium (Ru) phenanthroline complex and self-assembled onto QDs, resulting in controlled quenching of the QD emission. Different QD colors either alone or coupled to Ru−phen−peptide were then mixed together and optically interrogated. Composite spectra collected from mixtures ranging from four up to eight distinct QD colors were deconvoluted, and the individual QD photoluminescence (PL) loss due to charge transfer was quantified. The current multiplexing modality provides a simpler format for exploiting the narrow, size-tunable QD emissions than that offered by resonance energy transfer; for the latter, higher orders of multiplexing are limited by spectral overlap requirements.