Intracellular SERS hybrid probes using BSA–reporter conjugates
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Surface-enhanced Raman scattering (SERS) hybrid probes are characterized by the typical spectrum of a reporter molecule. In addition, they deliver information from their biological environment. Here, we report SERS hybrid probes generated by conjugating different reporter molecules to bovine serum albumin (BSA) and using gold nanoparticles as plasmonic core. Advantages of the BSA-conjugate hybrid nanoprobes over other SERS nanoprobes are a high biocompatibility, stabilization of the gold nanoparticles in the biological environment, stable reporter signals, and easy preparation. The coupling efficiencies of the BSA–reporter conjugates were determined by MALDI-TOF-MS. The conjugates’ characteristic SERS spectra differ from the spectra of unbound reporter molecules. This is a consequence of the covalent coupling, which leads to altered SERS enhancement and changes in the chemical structures of the reporter and of BSA. The application of the BSA–reporter conjugate hybrid probes in 3T3 cells, including duplex imaging, is demonstrated. Hierarchical cluster analysis and principal components analysis were applied for multivariate imaging using the SERS signatures of the incorporated SERS hybrid nanoprobes along with the spectral information from biomolecules in endosomal structures of cells. The results suggest more successful applications of the SERS hybrid probes in cellular imaging and other unordered high-density bioanalytical sensing.
KeywordsBovine serum albumin Nanosensor SERS multiplexing 3T3 cells Gold nanoparticles Hybrid nanoprobe
We thank M. Weller and R. Schneider (BAM Federal Institute for Materials Research and Testing) for providing the cell culture facility and P. Lasch (CytoSpec, Inc.) for Cytospec software. D. D. and J. K. acknowledge funding from the European Research Council (ERC Starting Grant no. 2594 32 MULTIBIOPHOT).
- 2.Otto A (ed) (1984) ‘Classical’ and ‘Chemical’ origins. Light scattering in solids IV, Electronic Scattering, Spin Effects, SERS and Morphic Effects. Springer, BerlinGoogle Scholar
- 6.Gühlke M, Selve S, Kneipp J (2012) Magnetic separation and SERS observation of analyte molecules on bifunctional silver/iron oxide composite nanostructures. J Raman Spectrosc 43(9):1204–1207Google Scholar
- 12.Kneipp J, Harald K, Anpuchchelvi R, Robert WR, Katrin K (2009) Optical probing and imaging of live cells using SERS labels. 40(1):1–5Google Scholar
- 32.Majoube M, Henry M (1991) Fourier-transform Raman and infrared and surface-enhanced Raman-spectra for rhodamine-6g. Spectrochim Acta A Mol Biomol Spectrosc 47(9–10):1459–1466Google Scholar
- 36.Bright NA, Reaves BJ, Mullock BM, Luzio JP (1997) Dense core lysosomes can fuse with late endosomes and are re-formed from the resultant hybrid organelles. J Cell Sci 110(Pt 17):2027–2040Google Scholar