Interfacing a heteropolytungstate complex and gelatin through a coacervation process: design of bionanocomposite films as novel electrocatalysts

Abstract

Novel modified electrodes exhibit excellent electrocatalytic performance for nitrite detection.

Single‐Molecule Magnet Behavior of Individual Polyoxometalate Molecules Incorporated within Biopolymer or Metal–Organic Framework Matrices

“…Upon drying, the viscous phase evolves to a glassy compound, owing to the vitreous transition of gelatin. As previously reported for other POM–gelatin bionanocomposites, Fe 6 W 18 POMs are confined within a gelatin network composed of coils and triple helices. Its orange color suggests the presence of the POMs, which was confirmed afterwards by a series of characterizations.…”

“…Fe 6 W 18 @Gel was synthesized following a coacervation process previously described for the immobilization of POMs in gelatin matrix . This process is mainly based on attractive electrostatic interactions between negatively charged POMs and positively charged gelatin chains.…”

“…Gelatin (Figure a), a cheap, abundant macromolecule obtained by hydrolytic degradation of mammalian or fish collagen, is widely used in food and pharmaceutical industries, and can form transparent and elastic gels. Gelatin has already proven a good matrix for the synthesis of bionanocomposites with diamagnetic POMs exhibiting topologies as different as heptamolybdate, decavanadate, Keggin‐type, or Keplerate and crown‐shaped species …”

Understanding and Tuning Bioinorganic Interfaces for the Design of Bionanocomposites

“… Schematic representations: (a) of the complex coacervation mechanism occurring between decavanadate entities (red dots) and gelatin chains (black lines), and (b) of a POM‐based electrode in which the [bmim][PF 6 ] ionic liquid insures an optimal interface between the heteropolytungstate‐gelatin film and the glassy carbon surface. Reproduced from refs 24,29. with permission from The Royal Society of Chemistry.…”

“…Overall, these studies confirm that POMs can reinforce gelatin‐based materials by acting as physical cross‐linkers above 27 °C and by stabilizing the thermally induced triple helices below 27 °C. On this principle, the conversion of a complex coacervate into an easily handled material has been achieved with the electroactive heteropolytungstate [BW 12 O 40 ] 5– cluster 29. Tuning the physical‐chemical conditions allowed the layer‐by‐layer deposition of the gelatin–heteropolytungstate coacervates as a well‐defined hybrid hydrogel.…”