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Electrochemiluminescence Resonance Energy Transfer between Ru(bpy) <sub/>3</sub><sup>2+</sup> and CdZnSe@ZnSe Quantum Dots for Ovarian Cancer Biomarker Detection
摘要： Herein, an enhanced electrochemiluminescence resonance energy transfer (ECL-RET) from Ru(bpy)3 2+ to the core/shell CdZnSe@ZnSe quantum dots (CdZnSe@ZnSe QDs) was first designed for ovarian cancer biomarker analysis. The TiO2 metal-organic frameworks (TiO2 MOFs) was used as promoter because of its unique semiconductor structure and high loading ability for Ru(bpy)3 2+. Additionally, Envision complex with numerous horseradish peroxidase (HRP) was employed to immobilize CdZnSe@ZnSe QDs, the acceptor of ECL-RET, which further improved the ECL emission of CdZnSe@ZnSe QDs. Concretely, reactive oxygen species (ROS), for instance, O2 ?? and OH?, were firstly yielded due to the catalytic ability of HRP to H2O2, and then the electron from O2 ?? or hole from OH? injection into the CdZnSe@ZnSe QDs, triggering an extremely strong ECL response of CdZnSe@ZnSe QDs. On the basis of all above features, a highly effective ECL-RET biosensor was elaborately established to detect the targets in the range of 1.00×10-6?1.00×102 ng/mL with low detection limit of 3.30×10-1 fg/mL (S/N=3). This work opened up a new avenue for developing high-performance ECL-RET biosensors and demonstrated the high potential of the new biomarker in clinical ovarian cancer screening.
关键词： CdZnSe@ZnSe QDs,TiO2 MOFs,Envision complex,ECL-RET,ovarian cancer biomarker
更新于2025-09-12 10:27:22
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Quenched Stochastic Optical Reconstruction Microscopy (qSTORM) with Graphene Oxide
摘要： Quenched Stochastic Optical Reconstruction Microscopy (qSTORM) was demonstrated with graphene oxide sheets, peptides and bacteria; a method of contrast enhancement with super-resolution fluorescence microscopy. Individual sheets of graphene oxide (GO) were imaged with a resolution of 16 nm using the quenching of fluorescence emission by GO via its large Resonant Energy Transfer (RET) efficiency. The method was then extended to image self-assembled peptide aggregates (resolution 19 nm) and live bacterial cells (resolution 55 nm, the capsular structure of E. coli from urinary tract infections) with extremely low backgrounds and high contrasts (between one and two orders of magnitude contrast factor improvements that depended on the thickness of the graphene oxide layer used). Graphene oxide films combined with STORM imaging thus provide an extremely convenient method to image samples with large backgrounds due to non-specifically bound fluorophores (either due to excess labelling or autofluorescent molecules), which is a common occurrence in studies of both biological cells and soft-condensed matter. The GO quenches the fluorescence across a thin layer at distances of less than 15 nm. Graphene oxide films coated with thin layers (≤15 nm) of polystyrene, polymethylmethacrylate and polylysine are shown to be effective in producing high contrast qSTORM images, providing a convenient modulation of sample/substrate interactions. The GO coatings can also provide an increased image resolution and a factor of 2.3 improvement was observed with the peptide fibres using a feature of interest metric,when there was a large non-specifically bound background.
关键词： Quenched Stochastic Optical Reconstruction Microscopy,contrast enhancement,peptide aggregates,qSTORM,fluorescence quenching,RET,bacterial cells,Resonant Energy Transfer,graphene oxide,super-resolution fluorescence microscopy
更新于2025-09-10 09:29:36
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Resonance Energy Transfer in Arbitrary Media: Beyond the Point Dipole Approximation
摘要： In this work, we present a comprehensive theoretical and computational study of donor/acceptor resonance energy transfer (RET) beyond the dipole approximation, in arbitrary inhomogeneous and dispersive media. The theoretical method extends Fo?rster theory for RET between particles (molecules or nanoparticles) to the case where higher multipole transitions in the donor and/or acceptor play a significant role in the energy transfer process. In our new formulation, the energy transfer matrix element is determined by a fully quantum electrodynamic expression, but its evaluation requires only classical electrodynamics calculations. By means of a time domain electrodynamical approach (TED), the matrix element evaluation involves the electric and magnetic fields generated by the donor and evaluated at the position of the acceptor, including fields associated with transition electric dipoles, electric quadrupoles, and magnetic dipoles in the donor, and the acceptor response to the electric and magnetic fields and to the electric field gradient. As an illustration of the benefits of the new formalism, we tested our method with a 512 atom lead sulfide (PbS) quantum dot as the donor/acceptor in vacuum, and with spherical nanoparticles (toy model) possessing designed transition multipoles. This includes an analysis of the effects of interferences between multipoles in the energy transfer rate. The results show important deviations from the conventional Fo?rster dipole theory that are important even in vacuum but that can be amplified by interaction with a plasmonic nanoparticle.
关键词： multipole transitions,resonance energy transfer,plasmonic nanoparticle,quantum electrodynamics,dipole approximation,RET
更新于2025-09-04 15:30:14