Graphene oxide (GO) is extensively proposed as an effective antibacterial agent in commercial product packaging and for various biomedical applications. However, the antibacterial mode of action of GO is yet hypothetical and unclear. Here we developed a new and sensitive fingerprint approach to study the antibacterial activity of GO and underlying mechanism, using Raman spectroscopy. Spectroscopic signatures obtained from biomolecules such as Adenine and proteins from bacterial cultures with different concentrations of GO, allowed us to probe the antibacterial activity of GO with its mechanism at the molecular level. Escherichia coli (E. coli) and Enterococcus faecalis (E. faecalis) were used as model micro-organisms for all the experiments performed. The observation of higher intensity Raman peaks from Adenine and proteins in GO treated E. coli and E. faecalis; correlated with induced death, confirmed by Scanning electron Microscopy (SEM) and Biological Atomic Force Microscopy (Bio-AFM). Our findings open the way for future investigations of the antibacterial properties of different nanomaterial/GO composites using Raman spectroscopy.
The naturally available cyclodextrin has opened up a wide range of research avenues because of its superior characteristics such as being non‐toxic, biocompatible, and edible. The cyclodextrin is the green multifunctional material that can add to the triboelectric series and extend its self‐powered applications. The ultrasonic synthesized cyclodextrin metal–organic framework (CD‐MOF) designed using sodium as a metal ion and cyclodextrin as a ligand for the triboelectric nanogenerator is reported. The various detailed characterizations of the CD‐MOFs give an insight into the properties of the synthesized material. The Kelvin probe force microscopy suggests three types of CD‐MOFs, exhibiting a positive potential. As per the surface potential, the output of the various CD‐MOF based TENG is varied as alpha CD MOF/Teflon > gamma CD‐MOF/Teflon > beta CD‐MOF/Teflon. The alpha CD MOF/Teflon TENG produces an electrical output of 152 V, 1.2 μA, and 14.3 nC, respectively. The fabricated device output is utilized for powering numerous low‐power electronics through a capacitor and bridge rectifier circuit. The multiunit Z‐shaped TENG device is attached to various surfaces such as the shoe heel and the backside of the school bag, and the corresponding energy harvesting response is demonstrated.
Nanotechnology advancements for stem cell differentiation, labeling, tracking and therapeutic applications in cardiac repair, bone, and liver regeneration are delineated.
The extracellular matrix (ECM) is a macromolecular network that can provide biochemical and structural support for cell adhesion and formation. It regulates cell behavior by influencing biochemical and physical cues. It is a dynamic structure whose components are modified, degraded, or deposited during connective tissue development, giving tissues strength and structural integrity. The physical properties of the natural ECM environment control the design of naturally or synthetically derived biomaterials to guide cell function in tissue engineering. Tissue engineering is an important field that explores physical cues of the ECM to produce new viable tissue for medical applications, such as in organ transplant and organ recovery. Understanding how the ECM exerts physical effects on cell behavior, when cells are seeded in synthetic ECM scaffolds, is of utmost importance. Herein we review recent findings in this area that report on cell behaviors in a variety of ECMs with different physical properties, i.e., topology, geometry, dimensionality, stiffness, and tension.
Label‐free biosensors offer accurate sensing capabilities due to the reliable quantification of biological and biochemical processes. These devices function by establishing a dynamic interaction of analyte and receptor molecules and convert this interaction into a measurable signal through a transducer. In recent decades, label‐free biosensors have attracted attention in biomedical applications due to the ease of linking nanomaterials with bioreceptor molecules. In this review, recent advances in sensitivity, specificity, and sensing mechanism related to label‐free biosensors of metallic nanoparticles of gold, silver, aluminium, copper, and zinc oxide are presented. Selected sensing methods based on fluorescence, surface plasmon resonance, surface‐enhanced Raman scattering, metal‐enhanced fluorescence, and electrochemical sensors are discussed. New measurement techniques and rapid progress of label‐free biosensors are going to play a vital role in the real‐time detection of biomarkers in clinical samples, such as blood plasma, serum, and urine, as well as in targeted drug delivery. Future trends of these label‐free biosensing mechanisms and their development are also discussed.
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