Highly efficient detector of the neurotransmitter ACh and AChE inhibitors

Among the variety of applications for biosensors one of the exciting frontiers is to utilize those devices as post-synaptic sensing elements in chemical coupling between neurons and solid-state systems. The first necessary step to attain this challenge is to realize highly efficient detector for neurotransmitter acetylcholine (ACh). Herein, we demonstrate that the combination of floating gate configuration of ion-sensitive field effect transistor (ISFET) together with diluted covalent anchoring of enzyme acetylcholinesterase (AChE) onto device sensing area reveals a remarkable improvement of a four orders of magnitude in dose response to ACh. This high range sensitivity in addition to the benefits of peculiar microelectronic design show, that the presented hybrid provides a competent platform for assembly of artificial chemical synapse junction. Furthermore, our system exhibits clear response to eserine, a competitive inhibitor of AChE, and therefore it can be implemented as an effective sensor of pharmacological reagents, organophosphates, and nerve gases as well. © 2007 Materials Research Society.

Addressing the cognitive and social influence inhibitors during the ideation stages of technology roadmapping workshops

Technology roadmapping workshops are essentially a social mechanism for exploring, creating, shaping and implementing ideas. The front-end of a roadmapping session is based on brainstorming in order to tap into the group's diverse knowledge. The aim of this idea stimulation activity is to capture and share as many perspectives as possible across the full scope of the area of interest. The premise to such group brainstorming is that the sharing and exchange of ideas leads to cognitive stimulation resulting in a greater overall group idea generation performance in terms of the number, variety and originality of ideas. However, it must be recognized that the ideation stage in a roadmapping workshop is a complex psychosocial phenomenon with underlying cognitive and social processes. Thus, there are downsides to group interactions and these must be addressed in order to fully benefit from the power of a roadmapping workshop. This paper will highlight and discuss the key cognitive and social inhibitors involved. These include: production blocking, evaluation apprehension, free riding/social loafing, low norm setting/matching. Facilitation actions and process adjustments to counter such negative factors will be identified so as to provide a psychosocial basis for improving the running of roadmapping workshops. © 2009 PICMET.

Enzyme-free glucose biosensor based on low density CNT forest grown directly on a Si/SiO2 substrate

A highly sensitive nonenzymatic amperometric glucose sensor was fabricated by using Ni nanoparticles homogeneously dispersed within and on the top of a vertically aligned CNT forest (CNT/Ni nanocomposite sensor), which was directly grown on a Si/SiO2 substrate. The surface morphology and elemental analysis were characterized using scanning electron microscopy and energy dispersive spectroscopy, respectively. Cyclic voltammetry and chronoamperometry were used to evaluate the catalytic activities of CNT/Ni electrode. The CNT/Ni nanocomposite sensor exhibited a great enhancement of anodic peak current after adding 5 mM glucose in alkaline solution. The sensor can also be applied to the quantification of glucose content with a linear range covering from 5 μM to 7 mM, a high sensitivity of 1433 μA mM-1 cm-2, and a low detection limit of 2 μM. The CNT/Ni nanocomposite sensor exhibits good reproducibility and long-term stability, moreover, it was also relatively insensitive to commonly interfering species, such as uric acid, ascorbic acid, acetaminophen, sucrose and d-fructose. © 2013 Elsevier B.V.