Functionalization of multilayer carbon shell-encapsulated gold nanoparticles for surface-enhanced Raman scattering sensing and DNA immobilization

Abstract

In this paper, we reported the surface modification of multilayer carbon shell-encapsulated gold nanoparticles (Carbon Nanoparticles, or CNPs) via an oxygen plasma treatment approach and their subsequent functionalization with extraneous gold (Au) nanoparticles for Surface-enhanced Raman Scattering (SERS) sensing and DNA immobilization. The oxygen plasma treatment process led to purification of the multilayer carbon shell, reduction of the shell thickness, and derivatization of carbon shell with functional carboxylic groups. This further opens potential opportunities for surface functionalization of CNPs with extraneous Au nanoparticles or λ-DNA fragments, which were both achieved through a well-defined carbodiimide based covalent linking chemistry without removing the CNPs from the substrate. The resulting CNP-Au nanoparticle hybrids as well as the CNP-DNA architectures were characterized using various microscopic and spectroscopic techniques. The CNP-Au nanoparticle hybrids were further used as highly-sensitive SERS substrate for the detection of trace amount water-containing organic molecule. Meanwhile, they were also fundamentally simulated for their plasmonic behavior using discrete dipole approximation (DDA) method to understand the basic Raman enhancement principle. On the other hand, highly-ordered assembly of CNP-DNA architectures were also demonstrated in detail for their great potential in future DNA detection/recognition and bio-device applications.

Superior Oxygen Reduction Reaction on Phosphorus‐Doped Carbon Dot/Graphene Aerogel for All‐Solid‐State Flexible Al–Air Batteries

“…As shown in Figure d, both t‐GO and P‐CD/G sample show the well‐defined D‐band and G‐band at 1344 and 1589 cm −1 , respectively . The former is related to surface defects and partially disordered structures of the sp 2 domains, while the latter stands for the E 2g vibration mode of sp 2 carbon domains, which suggests the degree of graphitization (quality of graphene) . In those two samples, the estimate I D / I G values are very similar (1.11 for t‐GO and 1.12 for P‐CD/G), suggesting that the phosphorus doping has an insignificant effect on the structural quality of the graphene matrix.…”

“…[31] The former is related to surface defects and partially disordered structures of the sp 2 domains, while the latter stands for the E 2g vibration mode of sp 2 carbon domains, which suggests the degree of graphitization (quality of graphene). [30] In those two samples, the estimate I D /I G values are very similar (1.11 for t-GO and 1.12 for P-CD/G), suggesting that the phosphorus doping has an insignificant effect on the structural quality of the graphene matrix. We also observe a slight red-shift of both bands for the doped sample, which is probably due to the change of lattice strain in the graphene matrix or the decrease of thermal conductivity due to the chemical doping.…”

“…The high‐resolution C 1s spectra for the t‐GO and P‐CD/G samples are shown in Figure 3 a,b. The deconvolution of both spectra indicates that the carbon component is dominated by the sp 2 hybridized CC bonds located at 284.8 eV, with some minor presence of hydrocarbon (COH) and carboxyl (COOH) groups . For the P‐CD/G nanocomposites, the P 2p spectra are deconvoluted into two peaks located at 131.2 and 133.8 eV (Figure c), which are corresponding to the PC bonds and PO bonds, respectively …”

“…The deconvolution of both spectra indicates that the carbon component is dominated by the sp 2 hybridized CC bonds located at 284.8 eV, with some minor presence of hydrocarbon (COH) and carboxyl (COOH) groups. [30] For the P-CD/G nanocomposites, the P 2p spectra are deconvoluted into two peaks located at 131.2 and 133.8 eV (Figure 3c), which are corresponding to the PC bonds and PO bonds, respectively. [28] Raman spectra were collected to further demonstrate the crystalline quality and defect information.…”

In-situ synthesis of graphene on surface of copper powder by rotary CVD and its application in fabrication of reinforced Cu-matrix composites

“…So far, most insitu CVD work in literature has been reported for developing carbon nanotubes (CNTs) and carbon nanofibers (CNFs) reinforced metal matrix composites [17][18][19][20][21], very few was dealt with Gr-metal matrix bulk composites [15] despite of some for in-situ CVD synthesis of Grmetal composite powders [22][23][24][25].…”