Au-covered nanographene oxide/PEG/PAMAM for surface-enhanced Raman scattering detection

Surface enhanced Raman spectroscopy (SERS) has been proposed as a promising technique in biological and chemical sample detection. Herein, with nanographene oxide (nGO) as substrate, we firstly prepared facile platforms (PAMAMG1-nGO-PEG and PAMAMG3-nGO-PEG) through the functionalization of nGO with biocompatible poly(ethylene glycol) (PEG) and hyperbranched polyamidamine (PAMAM) dendrimer. nGO/gold nanoparticle nanocomposites (Au@PAMAMG1-nGO-PEG and Au@PAMAMG3-nGO-PEG) were aptly fabricated through in situ covering of gold nanoparticles on PEG/PAMAM-functionalized nGO. A series of techniques were employed to confirm the covalent modification of nGO with different functional polymers and the uniformity of gold nanoparticles scattered over the nGO sheets in the as-prepared nanocomposites. Evidently, taking advantages of inherent electrochemical property of gold nanoparticles and their good dispersity on polymers and functionalized nGO, Au@PAMAMG1-nGO-PEG and Au@PAMAMG3-nGO-PEG both displayed sensitive and efficient SERS detection towards p-phenylenediamine, flavin adenine dinucletide and crystal violet (CV) molecules. It is foreseen that these nanocomposites can meet diverse SERS sensing applications with good dispersity, especially for environmental and clinical samples.