A critical review of nanohybrids: synthesis, applications and environmental implications

Abstract

Environmental context. Recent developments in nanotechnology have focussed towards innovation and usage of multifunctional and superior hybrid nanomaterials. Possible exposure of these novel nanohybrids can lead to unpredicted environmental fate, transport, transformation and toxicity scenarios. Environmentally relevant emerging properties and potential environmental implications of these newer materials need to be systematically studied to prevent harmful effects towards the aquatic environment and ecology.Abstract. Nanomaterial synthesis and modification for applications have progressed to a great extent in the last decades. Manipulation of the physicochemical properties of a material at the nanoscale has been extensively performed to produce materials for novel applications. Controlling the size, shape, surface functionality, etc. has been key to successful implementation of nanomaterials in multidimensional usage for electronics, optics, biomedicine, drug delivery and green fuel technology. Recently, a focus has been on the conjugation of two or more nanomaterials to achieve increased multifunctionality as well as creating opportunities for next generation materials with enhanced performance. With incremental production and potential usage of such nanohybrids come the concerns about their ecological and environmental effects, which will be dictated by their not-yet-understood physicochemical properties. While environmental implication studies concerning the single materials are yet to give an integrated mechanistic understanding and predictability of their environmental fate and transport, the importance of studying the novel nanohybrids with their multidimensional and complex behaviour in environmental and biological exposure systems are immense. This article critically reviews the literature of nanohybrids and identifies potential environmental uncertainties of these emerging 'horizon materials'.

Importance and challenges of environmental ligand binding and exchange: Introducing single molecule imaging as a model characterization technique

“…These can be present as simple monosaccharide structures (composed of 3 to 6 carbon atoms) 16 or more complexbranched polysaccharides (generally composed of 40 to 3000 carbon atoms) 16 . Among these carbohydrates, monosaccharides and disaccharides are the water soluble and biodegradable fractions 50 ; whereas, starch and glycogen, the primary energy sources of plants and animals, respectively, are the most biodegradable fractions in polysaccharides 50 .…”

“…99 The data gap in this literature further exacerbates via the expansion in the material space and development of complex nano-heterostructures 100 . These heterostructures can be classified as carbon-carbon, carbon-metal, core-shell meta-metal, among others 16 .…”

“…Energetic gain due to replacement of relatively smaller ligands with larger NOM 13 or reaction 14,15 of humic functional moieties with those at the capping agents will determine the kinetics and extent of ligand exchange. Furthermore, NM physicochemical properties will also influence NOM adsorption and ligand exchange processes 16 , where complexity in emergent nano-heterostructures present an additional degree of complexity [16][17][18][19] .…”

“…AAC TGA TCC TAC CAA TAC ACG CAT CCT TAG/Cy5/ DNA = (GT)15 -Rnd 16 -Cy5-SWNT, used to encapsulate SWNT:5' GTG TGT GTG TGT GTG TGT GTG TGT GTG TGT CTA AGG ATG CGT GTA T/Cy5/ 3' 4) cDNA = cRnd16 , hybridizes to DNA1 on SWNT:5'ATA CAC GCA TCC TTA G 3'…”

In Vivo Deep Tissue Fluorescence and Magnetic Imaging Employing Hybrid Nanostructures

“…[13][14][15][16][17][18][19][20] The resulting systems are so-called nanohybrids or hybrid nanostructures (HNS). [21][22][23][24] Recently, great efforts have been made to combine iron oxide NPs (IONPs) with visible/infrared luminescent nanoparticles (LNPs) 25 such as rare earth doped NPs or Quantum Dots (QDs). IONPs are known as contrast agents for magnetic resonance imaging (MRI) 26 and magnetic heating mediators.…”