Cyclodextrins as a Key Piece in Nanostructured Materials: Quantitation and Remediation of Pollutants

Abstract

Separation and pre-concentration of trace pollutants from their matrix by reversible formation of inclusion complexes has turned into a widely studied field, especially for the benefits provided to different areas. Cyclodextrins are non-toxic oligosaccharides that are well known for their host–guest chemistry, low prices, and negligible environmental impact. Therefore, they have been widely used as chiral selectors and delivery systems in the pharmaceutical and food industry over time. However, their use for extraction purposes is hampered by their high solubility in water. This difficulty is being overcome with a variety of investigations in materials science. The setting-up of novel solid sorbents with improved properties thanks to the presence of cyclodextrins at their structure is still an open research area. Some properties they can offer, such as an increased selectivity or a good distribution along the surface of a solid support, which provides better accessibility for guest molecules, are characteristics of great interest. This systematic review reports the most significant uses of cyclodextrins for the adsorption of pollutants in different-origin samples based on the works reported in the literature in the last years. The study has been carried out indistinctly for quantitation and remediation purposes.

Recent Advancements in Cyclodextrin-Based Adsorbents for the Removal of Hazardous Pollutants from Waters

“…Since cyclodextrins can self-adapt their structure to the structure of the adsorbed pollutant by reorganization, they are an ideal example of a material with great potential to remove organic contaminants from the environment. Adsorption of organic pollutants as a means of removal was tested on cyclodextrin-based [121]. Previous work has shown that cyclodextrins help remove endocrine-active compounds, pharmaceuticals, and other organic compounds [122,123].…”

The Contribution of NMR Spectroscopy in Understanding Perovskite Stabilization Phenomena

“…We recently tested native cyclodextrins (CDs) as solubility promoters for the two precursors [ 21 ]; the increase in the solubility of the inorganic moiety (PbI 2 ) was detected via UV-Vis absorption, whereas NMR was chosen for studying the interactions involving MAI and the macrocycles with different size cavities (α, β and γ in ascending order). Cyclodextrins were chosen because of their well-known ability to establish host-guest interactions with organic molecules: the guest, according to its functional groups, interacts with the hydrophobic inner cavity of the CD and/or with its hydrophilic external surface, decorated by –OH groups [ 52 , 53 , 54 , 55 ].…”

Magnetic material based on mesostructured silica functionalized with β-cyclodextrin to extract opium alkaloids in poppy seed infusions

“…On the other hand, in recent years, there has been an increasing interest of the scientific community the use of cyclodextrin (CD) with different purposes, which are natural products obtained from the enzymatic degradation of starch and therefore have a low price, negligible environmental impact and non-toxicity [14][15][16] . CDs are a family of natural torus-shaped cyclic oligosaccharides composed of 6 ( 𝛼-CD), 7 ( 𝛽-CD), and 8 ( 𝛾-CD) d -glucopyranose units linked by 𝛼− 1,4-glycosidic bonds, possessing hydrophobic inner cavities and hydrophilic outer faces.…”