ABSTRACTIn this study, HeLa cells were transfected to express a recombinant transmembrane domain of the platelet-derived growth factor receptor. Silver nanoparticle (Ag-NP) functionalized with terminal hydrazide was employed to specifically target the ketone-conjugated cell surface proteins. In addition, a nitrile functional group was incorporated onto the Ag nanoprobe to provide unique vibrational signature (∼ 2230 cm−1) in a window which is free from other cellular components. The designed Ag nanoprobe functions as both recognition and transduction elements in the detection of the expressed cell surface protein. Scanning electron microscopy and surface enhanced Raman spectroscopy (SERS) imaging of the nanoparticle (NP) labeled HeLa cells revealed that all the observed intense SERS signals originated from aggregated NPs. Although isolated Ag-NPs is capable of SERS enhancement, its enhancement factor is beyond the detestability of such imaging experiments. The results have implication in the future design of SERS nanosensors for in vivo detection application.
Surface-Enhanced Raman Spectroscopy Combined with Stable Isotope Probing to Monitor Nitrogen Assimilation at Both Bulk and Single-Cell Level