Gold nanoparticle integrated with nanostructured carbon and quantum dots: synthesis and optical properties

Abstract

Multilayer graphene shell encapsulated gold nanoparticle-quantum dot hybrids were derived by combining wetchemical, thermal, and covalent chemistry approaches. Uniformly patterned gold nanoparticles on a silicon substrate were obtained via gold film deposition in an electroless method followed by a thermal dewetting process. The resulting gold nanoparticles were further surface oxidized and utilized as catalysts for the chemical vapor deposition growth of multilayer graphene shell encapsulated on the gold nanoparticles (referred as "multilayer graphene shell encapsulated Au nanoparticle" or graphene nanoparticles (GNPs)). As a next step, the surface of GNPs was modified to result in carboxylic (−COOH) functionalities, which enabled carbodiimide-based covalent linking of amine-terminated CdS x Se 1-x @ZnS quantum dots (QDs) on the GNP surface. The GNPs and GNP-QD heterostructures were characterized using scanning and transmission electron microscopy for size, morphology, spatial distribution, and crystal structure evaluation. In addition, UV-vis, fluorescence spectroscopy, and discrete dipole approximation (DDA) modeling were utilized for understanding the band gap energies, fluorescence quenching, and light-matter interactions of the derived hybrids/heterostructures.

Review on Carbon Black and Graphite Derivatives-based Natural Rubber Composites

“…GO surfactant for the emulsification of organic solvents in water [57] electrode materials [58] transparent conductive films (touch screens, liquid crystal displays, organic photovoltaic cells, etc.) [40] gas sensor [59] energy storage device [60] EG electrochemical sensor thermal energy storage device [61] [62] rGO gas sensor [59] biosensors (as semi-conductor) [63] hole transport layer in polymer solar cells and LEDs [64] printable electronic device [43] GQD catalysts for the decomposition of solid composite propellants [47] stabilizing agent [65] bioimaging and biosensing [42] Carbon black and Graphene-Derivative-Based Polymer Composites [70] and varying the loading of these fillers. A greater improvement of thermal conductivity at 10 mass% of EG filler was recorded.…”

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

“…The fabrication and pattering of CNPs on the silicon substrate were carried out as previously reported by the authors [26][27][28][29][30][31]. Briefly, the silicon substrate was first treated in the piranha solution (H 2 SO 4 :H 2 O 2 = 4:1) at 100 ºC for 30 min to create surface -OH groups.…”

“…The DNA-anchoring process was continued for 24 h, leading to the formation of CNP-DNA architectures patterned on the silicon substrate. To further understand the SERS effect, discrete dipole approximation (DDA) method was used for simulating the surface plasmonic properties of the as-produced CNPs and CNP-QD hybrids [29,35]. The DDA method is based on the solution of the 3D Maxwell equation via the DDSCAT code developed by Draine and Flatau [35].…”

“…Recently, the authors reported a facile and scalable chemical vapor deposition (CVD) approach for the growth of multilayer carbon shell on Au nanoparticle [26][27][28]. This process led to the fabrication of multilayer carbon shell encapsulated Au nanoparticles (referred as carbon nanoparticles, CNPs), which preserve the unique optical properties from Au nanoparticle [29,30], and at the same time present the excellent surface chemical properties of carbon shell [31], which make CNPs of promise for future chemical sensor and bio-medicine applications. Nevertheless, for the as-produced CNPs, the surface of carbon shell is highly hydrophobic due to the presence of amorphous carbon (a normal by-product from CVD) and lack of surface functionalities such as carboxyl (-COOH) and hydroxyl (-COH) groups [32].…”

“…Nevertheless, for the as-produced CNPs, the surface of carbon shell is highly hydrophobic due to the presence of amorphous carbon (a normal by-product from CVD) and lack of surface functionalities such as carboxyl (-COOH) and hydroxyl (-COH) groups [32]. Meanwhile, the as-produced CNPs show a relatively thick carbon shell (~10-15 layers), which may slightly shadow the plasmonic properties of the Au nanoparticle core [29]. As a result, further surface modification of CNPs is necessary for the purpose of removing extra amorphous carbon, reducing the shell thickness and introducing more surface functionalities (-COOH and -COH).…”