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Heterogeneous sensor network for autonomous mediation of airborne chemical and biological threats
Berg HYACINTHE, Principal Author, FACTORIAEL FRANCE
The proliferation of chemical and biological warfare agents poses an eminent asymmetric threat with disastrous consequences to the national security of any nation. In addition, accidental release of airborne toxic agents in confined spaces constitutes another challenge to public safety worldwide. Accordingly, an array of technologies and techniques ranging from optical to potentiometric, resonant, thermal-detection, Ion-sensitive, electrochemical, conductimetric, amperometric, potentiometric, and calorimetric biosensors has been developed.
Today existing sensor-based solutions operate under a defunct “detect-to-warn” paradigm and, as such, require the post-incident intervention of biohazard experts located hundreds, if not, thousands of miles away. As it will be demonstrated infra, some of the most dangerous airborne chemicals attack, within minutes, the acetylcholinesterase (AChE), the primary target of inhibition by organophosphorus compounds such as nerve agents and pesticides. The AChE is an enzyme that plays an important role in activities linked to the central nervous system, respiratory organs and the immune system, notably at neuromuscular junctions and cholinergic brain synapses, where it is used to terminate synaptic transmission.
As an innovative alternative, the autonomous biochemical mediation method, based on a network of heterogeneous sensors, seeks to automatically detect, identify, notify, and more importantly, neutralize airborne biochemical threats in confined spaces
Impact Of Molecular Surface Charge On Monitoring Of Biorecognition Events By Electrical Impedance Spectroscopy
Yaron Ram, MSc Student, Tel Aviv University
Electrical Impedance Spectroscopy (EIS) is a powerful tool for detection and characterization of biorecognition events taking place on electrode's surface. It enables highly sensitive measurements without destroying the biological samples.
Employing a redox couple as a probe in impedance measurements provides high sensitivity to the change of the surface charge. This change can either increase or decrease the measured resistance to electrochemical charge transfer.
The goal of this work is to use EIS for biodetection of ligand-binding protein interaction, gaining physical understanding of the detection mechanism.
The Avidin-Biotin interaction was used for the study of biotinylated Horseradish Peroxidase (HRP) binding to Avidin adsorbed on the surface of gold electrode.
Using [Fe(CN)6]3-/[Fe(CN)6]4- as redox couple, we discovered that reducing the positive charge of Avidin by chemical modification, enabled recording of high change in resistance, resulting in improved sensitivity. A detection limit of biotinylated HRP in the range of few nM was achieved.
This work shows that the nature and amount of charges on either the analyte or the binding protein have great effect on biosensing by EIS in comparison to Cyclic Voltammetry and ELISA.
Pathogenesis and Clinical Presentation of Throat Candidiasis in Durrës area, Albania.
Anisa Liti, Student, Aleksandër Moisiu University
Candidiasis, commonly called yeast infection or thrush, is a fungal infection of any of the Candida spp., of which Candida albicans is probably the most
common.
In most individuals, C. albicans is a member of the normal human microbiome, resides as a lifelong, harmless commensal. Under certain circumstances, however, C. albicans can cause infections that range from superficial infections of the skin to life-threatening systemic infections. C. albicans is able to switch reversibly between yeast and hyphal growth forms in response to environmental cues.
In this study, 1317 throat sampes were examined. These samples were recived by the Microbiology Laboratory of DRSH, Durrës, Albania, collected between April 2012 and December 2013.
We focused our attention on the prevalence of C. albicans in throat and it’s relation to sex, seasons and age.
It resulted that 372 out of 1317 samples were infected by C. albicans throat infections.
The infection was mostly prevalent in women, 63% out of all positive results.
The age group most affected were 76-90 years old and 46-60 years old.
We found this infection highly prevalent in autumn with 26% of positive results
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