Shedding new light on the integrity of gold nanoparticle-fluorophore conjugates for cell biology with four-wave-mixing microscopy - dataset
This is a cross-disciplinary work at the physics/life science interface which addresses an important question in the use of gold nanoparticles (AuNPs) conjugated to fluorescent molecules for cell biology, namely whether the fluorophore is a faithful reporter of the nanoparticle location.
AuNPs are among the most widely investigated systems in nano-medicine research for applications in intracellular imaging and sensing, drug delivery and photothermal therapy, owing to their small sizes, biocompatibility, ease of surface functionalisation and bio-conjugation.
In this context, a particularly interesting system is that of a AuNP-fluorophore conjugate, whereby a fluorescently labelled biomolecule (e.g. a protein ligand, nucleotide, peptide, antibody) is attached
onto the AuNP surface, and its uptake and intracellular fate is followed in situ in real time by fluorescence microscopy. AuNPs are historically well known to biologists as markers for electron microscopy due to their high electron density; hence these conjugate are specifically useful probes for correlative light electron microscopy. However, an important question that has remained elusive to answer is whether the fluorescence readout is actually a reliable reporter of the AuNP location. This is because it is challenging with current optical techniques to directly visualise a single small AuNP against the endogenous scattering, absorption and phase contrast in a highly heterogeneous three-dimensional cellular environment.
These data demonstrate the application of a novel optical microscopy technique developed in our lab (four-wave mixing (FWM) interferometry) to directly image single small AuNPs background-free inside cells with high 3D spatial resolution. The data show four different AuNP-fluorophore conjugates imaged inside two different cell types. By correlative fluorescence-FWM microscopy, the data show that, in most cases, fluorescence emission originated from unbound fluorophores rather than from fluorophores attached
to nanoparticles. Fluorescence detection was also severely limited by photobleaching, quenching and autofluorescence background.
The datasets consist of images and numerical data.
Images consist of two groups: experimental and calculated datasets.
Experimental images are optical microscopy datasets obtained using: i) Differential Interference Contrast Microscopy (DIC), 2) FWM microscopy, 3) Confocal fluorescence microscopy, 4) extinction microscopy, 5) wide-field epifluorescence microscopy. Calculated datasets are images of the cross correlation coefficient as a function of relative translation coordinates, calculated from the experimental images.
Numerical data consist of:
1) One dimensional cut profiles along images. Data are provided as Origin plots where original datasets can be retrieved.
2) Plots of representative values of extinction cross-sections. Data are provided as Origin plots where original datasets can be retrieved.
3) Scatter plot from a two-channel/colour fluorescence image, showing the intensity of one colour channel in a given pixel as the x-coordinate and the fluorescence intensity of the second channel at the same pixel as the y-coordinate. Data are provided as Origin plots where original datasets can be retrieved.
4) Scatter plot showing the fluorescence flux (in units of detected photoelectrons/s) versus extinction cross-section of nanoparticles. Data are provided as Origin plots where original datasets can be retrieved.
Research results based upon these data are published at https://doi.org/10.1039/C9NR08512B
Funding
Shedding new light on cells with coherent multiphoton nanoscopy
Engineering and Physical Sciences Research Council
Find out more...Physics-life sciences C-DIP fellowship fund (2010-10-01 - 2015-09-30); Borri, Paola. Funder: Engineering and Physical Sciences Research Council
Laser-Guided nanoparticles and Cell Scalextrics
Engineering and Physical Sciences Research Council
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Engineering and Physical Sciences Research Council
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Engineering and Physical Sciences Research Council
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