Localization of the E. coli Dps protein molecules in a silicon wires under removal of residual salt

The work is related to the removal of residual salts in hybrid structures formed as a result of silicon wires arrays combining with a nanomaterial of natural origin – bacterial ferritin-like protein Dps. The study of the morphology and composition of the surface and the bulk part of the hybrid structure as a result of combination and subsequent washing in water was carried out. The method of metal-assisted wet chemical etching was used to obtain silicon wires arrays. To obtain recombinant protein, Escherichia coli BL21*(DE3) cells with chromatographic purification were used as producers. The combination of silicon wires with protein molecules was carried out by layering them in laboratory conditions, followed by drying. The residual salt found earlier in the hybrid material was removed by washing in water. The resulting hybrid material was studied by scanning electron microscopy and X-ray photoelectron spectroscopy. A well-proven complementary combination of scanning electron microscopy and X-ray photoelectron spectroscopy together with ion etching was used to study the morphology of the hybrid material “silicon wires – bacterial protein Dps” and the composition with physico-chemical state respectively. In arrays of silicon wires with a wire diameter of about 100 nm and a distance between them from submicron to nanometer sizes, protein was found as a result of layering and after treatment in water. At the same time, the amount of residual NaCl salt is minimized on the surface of the hybrid structure and in its volume. The obtained data can be used in the development of coating technology for the silicon wires developed surface available for functionalization with controlled delivery of biohybrid materia

Localization of the E. coli Dps protein molecules in a silicon wires matrix according to scanning electron microscopy and X-ray photoelectron spectroscopy

The work is related to the study of the morphological features of silicon wires arrays combined with a nanomaterial of natural origin, a bacterial ferritin-like protein Dps, and their relationship with the composition of the surface and interior. A silicon wires array was formed by metal-assisted wet chemical etching. To obtain recombinant protein, Escherichia coli BL21*(DE3) cells were used as producers, and purification was carried out by the chromatography method. The combination of silicon wires with protein molecules was carried out by layering under laboratory conditions, followed by drying. The resulting hybrid material was studied by scanning electron microscopy and X-ray photoelectron spectroscopy. The initial silicon wires array had sharp boundaries on the surface. The diameter of the silicon wires was about 100 nm, while the distances between the wires can vary widely, reaching several hundred nanometres or be less than 100 nanometres, depending on the formation conditions, in the absence of noticeable transition layers. The pores formed in this way are available for filling with protein during deposition. The effectiveness of using the scanning electron microscopy method to study the morphology of the hybrid material “silicon wires – bacterial protein Dps” as well as X-ray photoelectron spectroscopy method together with ion etching for the investigation of the composition and physico-chemical of the hybrid material was demonstrated. Complementary results have shown that the molecular culture, which is a solution of oligomers of the recombinant Dps protein of E.coli bacterial cells, can penetrate deep into the pores of the silicon wires array with an extremely developed surface. The possibility of the control of the filling of silicon wires arrays by varying the pore morphology and other modes of formation of structures and their surface has been demonstrated. The obtained data can be used to study the possibilities of the functionalization of the developed surface of silicon wires by their driven coating with controlled delivery of biohybrid material