Graphene-Diatom Silica Aerogels for Efficient Removal of Mercury Ions from Water

Zhang

et al. 2018

Adv Funct Materials

Microorganisms are widely used as the biotemplates for producing micro/ nanomaterials owing to their unique features, such as exquisite morphology, renewable, and environmentally friendly. However, mass intracellular synthesis of uniformly dispersed nanoparticles (NPs) inside microorganisms is still challenging, especially in a predictable and controllable manner. Here, a facile and efficiency strategy is proposed to controllably produce highly dispersed and surfactant-free Pd@Ag core-shell NPs within the Spirulina platensis (Sp.) cells. In this approach, the Sp. cells' permeability is enhanced by the hydrochloric acid treatment first, which enables the Pd NPs penetrate the cell envelope and distribute uniformly inside the cells, and then they can work as the catalytic seeds for the following electroless silver deposition, resulting in the intracellular fabrication of Pd@Ag core-shell NPs with no agglomeration. The Pd@Ag NPs show excellent catalytic activity (turnover frequency is up to 2893 h −1 for the 6.32 nm Pd@Ag NPs), good stability, and recyclability toward the 4-nitrophenol reductions. The excellent properties are attributed to the asymmetrical core-shell structure, small size, and good dispersion of Pd@Ag NPs. Due to its facility, cost-effectiveness, and versatility, this method can be expanded to other microorganisms, so it opens tremendous opportunities for various metallic nanoparticles intracellular synthesis as well as the practical application.

Section: Introductionmentioning

confidence: 99%

Facile Fabrication of Highly Dispersed Pd@Ag Core–Shell Nanoparticles Embedded in Spirulina platensis by Electroless Deposition and Their Catalytic Properties

Zhang

et al. 2018

Adv Funct Materials

“…Other 2D structures include graphene and graphene oxide (GO), which show promising potential for SERS technology due to the high ratio of surface to volume, good electrical performance, and high affinity for some molecules. 75,76 Graphene grown on Cu foils was used as the deposition substrate for Au nanoislands, which increases the enhancement factor. 77 In addition to graphene, silicon is also considered as a potential substrate for plasmonic materials.…”

Section: Structuresmentioning

confidence: 99%

Are plasmonic optical biosensors ready for use in point-of-need applications?

Liu

Jalali

Mahshid

et al. 2020

Analyst

142

Plasmonics has drawn significant attention in the area of biosensors for decades due to the unique optical properties of plasmonic resonant nanostructures. While the sensitivity and specificity of molecular detection relies significantly on the resonance conditions, significant attention has been dedicated to the design, fabrication, and optimization of plasmonic substrates. The adequate choice of materials, structures, and functionality goes hand in hand with a fundamental understanding of plasmonics to enable the development of practical biosensors that can be deployed in real life situations. Here we provide a brief review of plasmonic biosensors detailing most recent developments and applications. Besides metals, novel plasmonic materials such as graphene are highlighted. Sensors based on Surface Plasmon Resonance (SPR), Localized Surface Plasmon Resonance (LSPR), and Surface Enhanced Raman Spectroscopy (SERS) are presented and classified based on their materials and structure. In addition, most recent applications to environment monitoring, health diagnosis, and food safety are presented. Potential problems related to the implementation in such applications are discussed and an outlook is presented. Fundamentals of plasmonic materialsPlasmonics studies the interaction of light with metals or metallic nanostructures. Other materials such as graphene also exhibit plasmonic resonance due to the availability of con-

“…Aerogels of graphene coated, chemically modified silica diatoms, impregnated with iron nanoparticles have shown a high affinity towards mercury ions, with an adsorption capacity of >500 mg/g [193]. The fabrication of GO-microbots, consisting of layers of GO, nickel and platinum have been used as environmental clean-up agents for the removal of lead from water, where depending on the GO-microbot dose, up to 95% removal of lead was observed [194].…”

Section: Emerging Composite Graphene Materials For Enhanced Water Purmentioning

confidence: 99%

Activated Carbon, Carbon Nanotubes and Graphene: Materials and Composites for Advanced Water Purification

Sweetman

May²,

Mebberson³

et al. 2017

160

Abstract:To ensure the availability of clean water for humans into the future, efficient and cost-effective water purification technology will be required. The rapidly decreasing quality of water and the growing global demand for this scarce resource has driven the pursuit of high-performance purification materials, particularly for application as point-of-use devices. This review will introduce the main types of natural and artificial contaminants that are present in water and the challenges associated with their effective removal. The efficiency and performance of recently developed materials for water purification, with a focus on activated carbon, carbon nanotubes and graphene will be discussed. The recent advances in water purification using these materials is reviewed and their applicability as point-of-use water purification systems discussed.