Over the past years, research attention has been focusing more on waste-derived, naturally derived, and renewable materials, in the view of a more sustainable economy. In this work, different topical formulations were obtained from the valorization of marine and agro-industrial by-products and the use of Carbopol 940 as gelling agent. In particular, the combination of extracts obtained from the marine snail, Rapanosa venosa, with Cladophora vagabunda and grape pomace extracts, was investigated for wound healing purposes. Rapana venosa has demonstrated wound healing properties and antioxidant activity. Similarly, grape pomace extracts have been shown to accelerate the healing process. However, their synergic use has not been explored yet. To this aim, four different formulations were produced. Three formulations differed for the presence of a different extract of Rapana venosa: marine collagen, marine gelatin, and collagen hydrolysate, while another formulation used mammalian gelatin as further control. Physico-chemical properties of the extracts as well as of the formulations were analyzed. Furthermore, thermal stability was evaluated by thermogravimetric analysis. Antioxidant capacity and biological behavior, in terms of cytocompatibility, wound healing, and antimicrobial potential, were assessed. The results highlighted for all the formulations (i) a good conservation and thermal stability in time, (ii) a neutralizing activity against free radicals, (iii) and high degree of cytocompatibility and tissue regeneration potential. In particular, collagen, gelatin, and collagen hydrolysate obtained from the Rapana venosa marine snail represent an important, valuable alternative to mammalian products.

In this work, the development of an electrochemical sensor for melatonin determination is presented. The sensor was based on Sonogel-Carbon electrode material (SNGCE) and Au nanoparticles (AuNPs). The low-cost and environmentally friendly SNGCE material was prepared by the ultrasound-assisted sonogel method. AuNPs were prepared by a chemical route and narrow size distribution was obtained. The electrochemical characterization of the SNGCE/AuNP sensor was carried out by cyclic voltammetry in the presence of a redox probe. The analytical performance of the SNGCE/AuNP sensor in terms of linear response range, repeatability, selectivity, and limit of detection was investigated. The optimized SNGCE/AuNP sensor displayed a low detection limit of 8.4 nM melatonin in synthetic samples assessed by means of the amperometry technique. The potential use of the proposed sensor in real sample analysis and the anti-matrix capability were assessed by a recovery study of melatonin detection in human peripheral blood serum with good accuracy.

The aim of this study is the preparation of nanostructured copper(II) oxide-based materials (CuONPs) through a facile additive-free polyol procedure that consists of the hydrolysis of copper(II) acetate in 1,4-butane diol and its application in hydrogen peroxide sensing. The nonenzymatic electrochemical sensor for hydrogen peroxide determination was constructed by drop casting the CuONP sensing material on top of a glassy carbon electrode (GCE) modified by a layer of poly(3,4-ethylenedioxythiophene) conducting polymer (PEDOT). The PEDOT layer was prepared on GCE using the sinusoidal voltage method. The XRD pattern of the CuONPs reveals the formation of the monoclinic tenorite phase, CuO, with average crystallite sizes of 8.7 nm, while the estimated band gap from UV–vis spectroscopy is of 1.2 eV. The SEM, STEM, and BET analyses show the formation of quasi-prismatic microaggregates of nanoparticles, with dimensions ranging from 1 µm up to ca. 200 µm, with a mesoporous structure. The developed electrochemical sensor exhibited a linear response toward H₂O₂ in the concentration range from 0.04 to 10 mM, with a low detection limit of 8.5 μM of H₂O₂. Furthermore, the obtained sensor possessed an excellent anti-interference capability in H₂O₂ determination in the presence of interfering compounds such as KNO₃ and KNO₂.