Advances in Nanomaterials Based on Cashew Nut Shell Liquid

Cashew nut shell liquid (CNSL), obtained as a byproduct of the cashew industry, represents an important natural source of phenolic compounds, with important environmental benefits due to the large availability and low cost of the unique renewable starting material, that can be used as an alternative to synthetic substances in many industrial applications. The peculiarity of the functional groups of CNSL components, such as phenolic hydroxyl, the aromatic ring, acid functionality, and unsaturation(s) in the C15 alkyl side chain, permitted the design of interesting nanostructures. Cardanol (CA), anacardic acid (AA), and cardol (CD), opportunely isolated from CNSL, served as building blocks for generating an amazing class of nanomaterials with chemical, physical, and morphological properties that can be tuned in view of their applications, particularly focused on their bioactive properties

Developments in the synthesis of a water compatible molecularly imprinted polymer as artificial receptor for detection of 3-nitro-L-tyrosine in neurological diseases

A highly selective water compatible molecularly imprinted polymer (MIP) for 3-nitro-L-tyrosine (3NT), an oxidative stress marker associated with neurodegenerative disorders, was prepared and its use as solid-phase extraction (SPE) sorbent material was demonstrated. The MIP was prepared by bulk polymerization using methacrylic acid as functional monomer and acetonitrile as porogen with traces of acetic acid and trifluoroacetic acid. In order to evaluate its binding properties, the MIP was analyzed by batch rebinding experiments and subsequently used as SPE sorbent for the selective clean-up and pre-concentration of 3NT from standard solutions and spiked human urine samples. The results obtained from batch rebinding experiments showed the presence of two association constants corresponding to high-affinity (Ka 4.20X103 M-1) and low-affinity (Ka 0.79X103 M-1) binding sites. Standard mixture solution loaded on MIP-SPE cartridge gave a recovery of 95% for 3NT, while the other compounds were totally eluted during washing step. Percentage of recovery higher than 90%, with relative standard deviation of 2%, was also obtained when a maximum of 55 microg of 3NT is used in spiked urine sample and loaded into the cartridge. Validation of the analytical method for 3NT quantification in human urine gave 0.7 micromg mL-1 of limit of detection, a linear range of 2.5–55 microg mL-1 with a relative standard deviation of 2%

Urinary l-kynurenine quantification and selective extraction through a molecularly imprinted solid-phase extraction device

L-Kynurenine is an endogenous metabolite generated by the catabolic pathway of L-tryptophan and it could be a potential biomarker to test the efficacy of several checkpoint inhibitors that have already reached the clinical trials in the antitumor therapy. Thus, a molecularly imprinted polymer specific for the recognition of this metabolite was synthesized and used as innovative system in solid-phase extraction technique for the specific extraction and quantification of L-kynurenine in human urine. The off-line system was firstly tested on L-kynurenine standard solutions, allowing recoveries up to 97.7% (relative standard deviation = 2.2%) and then applied to fortified and deproteinated human urine samples, where a recovery of 84.1% (relative standard deviation = 3.1%) was obtained. The method was validated and it revealed a good linearity in the range of 0.157–20 μg/mL (r2 = 0.9992). The optimized procedure demonstrated a good feasibility on biological samples, allowing a ready quantification of L-kynurenine in the human urine, where the metabolite was found at a very low concentration (0.80 μg/mL). The extraction system developed could attract attention of pharmaceutical industries for L-kynurenine production as potential drug in the treatment of autoimmune disorders through its extraction and purification from biological matrixes

Novel polymeric sorbents based on imprinted Hg(II)-diphenylcarbazone complexes for mercury removal from drinking water

This study describes the preparation of ion-imprinted polymers (IIPs) for the selective removal of Hg(II) ions from aqueous media. Polymeric sorbents were prepared using different synthesis approaches to understand the influence of diphenylcarbazone (DPC), used as non-polymerizable ligand, on absorption performance. In particular, bulk polymerization was first used to prepare two polymers, IIP1 and IIP2, in the absence and presence of DPC. The trapping of the ligand in IIP2, demonstrated by Fourier Transform Infrared Spectroscopy, promotes the formation of ternary complexes with mercury ions, and 4-vinylpyridine induces an increase in binding performance, as indicated by the Kavalues (1.7 × 103±0.4 M−1 and 12.1 × 103±0.5 M−1, respectively) of IIP1 and IIP2 high affinity binding sites. A third polymer (IIP3) was also synthesized using precipitation polymerization to evaluate the contribution of morphological characteristics on absorption performance compared with the addition of DPC. Competitive studies revealed a stronger influence of IIP3 morphology on selectivity performance. Indeed, monodisperse microbeads were obtained only in this case. Finally, the applicability of the polymers to real-world samples was demonstrated through batch experiments using drinking water spiked with 1μgml−1 of Hg(II) ions, and the best removal efficiency of nearly 80% was obtained for IIP2