ABSTRACT
This article aims to unpack global citizenship education (GCE) as a concept, arguing that a certain moving forward is needed in the scholarship to allow true engagement of educators and thus students with the topic. It suggests that the contemporary research directions are entangled with strong trends of political correctness and a contrariness agenda, de facto nullifying school-based praxis. It also notes several assumptions in the GCE literature that may benefit from re-examination to critically engage with criticisms of GCE.
ABSTRACT
The rapid and reliable detection of pathogenic microorganisms is an important issue for the safety and security of our society. Here we describe the use of a sensitive, inexpensive, amperometric, phage-based biosensor for the detection of extremely low concentrations of Bacillus cereus and Mycobacterium smegmatis as models for Bacillus anthracis (the causative agent of anthrax) and for Mycobacterium tuberculosis (the causative agent of tuberculosis), respectively. The detection procedure developed here enabled the determination of bacteria at a low concentration of 10 viable cells/mL within 8 h. This experimental setup allows the simultaneous analysis of up to eight independent samples, using disposable screen-printed electrodes.
Subject(s)
Bacillus cereus/chemistry , Bacteriophages , Biosensing Techniques/methods , Mycobacterium smegmatis/chemistry , Bacillus cereus/enzymology , Bacillus cereus/virology , Electrochemistry , Mycobacterium smegmatis/enzymology , Mycobacterium smegmatis/virology , alpha-Galactosidase/metabolismABSTRACT
The fabrication and notably improved performance of composite electrodes based on modified self-assembled diphenylalanine peptide nanotubes is described. Peptide nanotubes were attached to gold electrodes, and we studied the resulting electrochemical behavior using cyclic voltammetry and chronoamperometry. The peptide nanotube-based electrodes demonstrated a direct and unmediated response to hydrogen peroxide and NADH at a potential of +0.4 V (vs SCE). This biosensor enables a sensitive determination of glucose by monitoring the hydrogen peroxide produced by an enzymatic reaction between the glucose oxidase attached to the peptide nanotubes and glucose. In addition, the marked electrocatalytic activity toward NADH enabled a sensitive detection of ethanol using ethanol dehydrogenase and NAD+. The peptide nanotube-based amperometric biosensor provides a potential new tool for sensitive biosensors and biomolecular diagnostics.
Subject(s)
Biosensing Techniques/instrumentation , Biosensing Techniques/methods , Glucose Oxidase/metabolism , Nanotubes, Peptide/chemistry , Electrodes , Glucose/analysis , Glucose/metabolism , Gold , Hydrogen Peroxide/metabolism , Microscopy, Electron, Scanning , NADP/metabolism , Nanotubes, Peptide/ultrastructure , Sensitivity and SpecificityABSTRACT
Here we describe a novel electrochemical biosensing platform based on biocompatible, well-ordered, self-assembled diphenylalanine peptide nanotubes. Voltammetric and time-based amperometric techniques were applied to demonstrate the ability of the peptide nanotubes to improve the electrochemical parameters of graphite electrodes. The findings clearly show that this novel class of peptide nanotubes provides an attractive component for future electroanalytical devices.
