Promising supercapacitor electrodes based immobilization of proteins onto macroporous Ni foam materials

Immobilizing biocomponents on solid surfaces is a critical step in the development of new devices for future biological, medical, and elec- tronic applications. Therefore, numerous integrated films were recently developed by immobilizing different proteins or enzymes on electrode surfaces. In this work, hemeproteins were safely immobilized onto macroporous nickel-based electrodes while maintaining their functionality. Such modified electrodes showed interesting pseudo-capacitive behavior. Among hemeproteins, hemoglobin （Hb） film has a higher electro- chemical performance and greater charge/discharge cycling stability than myoglobin （Mb） and cytochrome C （CytC）. The heme group in an alkaline medium could induce the formation of superoxides on the electrode surface. These capacitive features of hemeprotein-Ni electrode were related to strong binding sites between hemeproteins and porous Ni electrode, the accumulation of superoxide or radicals on the Ni sur- face, and facile electron transfer and electrolyte diffusion through the three-dimensional macroporous network. Thus, these new protein-based supercapacitors have potential use in free-standing platform technology for the development of implantable energy-storage devices.

Comparative study between three carbonaceous nanoblades and nanodarts for antimicrobial applications

The design of nanostructured materials occupies a privileged position in the development and management of affordable and effective technology in the antibacterial sector.Here,we discuss the antimicrobial properties of three carbonaceous nanoblades and nanodarts materials of graphene oxide(GO),reduced graphene oxide(RGO),and single-wall carbon nanotubes(SWCNTs)that have a mechano-bactericidal effect,and the ability to piercing or slicing bacterial membranes.To demonstrate the significance of size,morphology and composition on the antibacterial activity mechanism,the designed nanomaterials have been characterized.The minimum inhibitory concentration(MIC),standard agar well diffusion,and transmission electron microscopy were utilized to evaluate the antibacterial activity of GO,RGO,and SWCNTs.Based on the evidence obtained,the three carbonaceous materials exhibit activity against all microbial strains tested by completely encapsulating bacterial cells and causing morphological disruption by degrading the microbial cell membrane in the order of RGO>GO>SWCNTs.Because of the external cell wall structure and outer membrane proteins,the synthesized carbonaceous nanomaterials exhibited higher antibacterial activity against Gram-positive bacterial strains than Gram-negative and fungal microorganisms.RGO had the lowest MIC values(0.062,0.125,and 0.25 mg/mL against B.subtilis,S.aureus,and E.coli,respectively),as well as minimum fungal concentrations(0.5 mg/mL for both A.fumigatus and C.albicans).At 12 hr,the cell viability values against tested microbial strains were completely suppressed.Cell lysis and death occurred as a result of severe membrane damage caused by microorganisms perched on RGO nanoblades.Our work gives an insight into the design of effective graphene-based antimicrobial materials for water treatment and remediation.

Strain engineering in electrocatalysis:Strategies,characterization,and insights

Strain engineering,as a cutting-edge method for modulating the electronic structure of catalysts,plays a crucial role in regulating the interaction between the catalytic surface and the adsorbed molecules.The electrocatalytic performance is influenced by the electronic structure,which can be achieved by introducing the external forces or stresses to adjust interatomic spacing between surface atoms.The challenges in strain engineering research lie in accurately understanding the mechanical impact of strain on performance.This paper first introduces the basic strategy for generating the strain,summarizes the different strain generation forms and their advantages and disadvantages.The progress in researching the characterization means for the lattice strains and their applications in the field of electrocatalysis is also emphasized.Finally,the challenges of strain engineering are introduced,and an outlook on the future research directions is provided.