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Both surface-enhanced Raman spectroscopy (SERS) and tip-enhanced Raman spectroscopy (TERS) is benefited from the the localized surface plasmon resonance (LSPR) of metallic nanostructures.They can provide high sensitivity with molecular fingerprint information for ultratrace analysis,even down to single molecules.To take the challenge of using SERS for bioanalysis,we developed a method to modify the surface of SERS active nanoparticle colloids or solid SERS substrates with some halide ions.Proteins were found to interact with the modified substrate via electrostatic interaction.The SERS signal of protein is at least enhanced by 1000 time over the solution species,with almost identical feature to that of the solution signal of proteins.The methods have been applied to study the lysosome,BAS,avidin,hemoglobin,cytochrome c and etc.The detection limit for lysosome can be as low as 3 μg/mL.The ability to obtain SERS signal of protein with very good reproducibility and high sensitivity is extremely important to the wider application of SERS technique to biological systems.We further systematically study the methodology of using a probe molecule to monitor the local pH environment of live cells.It was found that it is vitally important to control the interfacial structure and measuring condition in order to obtain reliable pH response.On the other hand,TERS can not only provide very high sensitivity but also high spatial resolution,which is extremely important when it is used to study the dynamic processes on surfaces.The high spatial resolution allows the extraction of signals from the "some molecules" or even "single molecules" by significantly lowering the background averaged signal.Using thiols for example,we found that TERS can clearly provide the immersing time dependent of the self-assemble mononlayer,which is a reflection of the strong interaction between the thiol molecules.The dynamic diffusion process could be revealed by the combined two-dimensional and autocorrelation analyses.