Wireless sensor networks are often located in areas where access to them is difficult or dangerous. Today, in wireless sensor networks, cluster-based routing protocols by dividing sensor nodes into distinct clusters and selecting local head-clusters to combine and send information of each cluster to the base station and balanced energy consumption by network nodes, get the best performance ...

A flexible enzymatic acetylcholinesterase biosensor based on an electrolyte-gated carbon nanotube field effect transistor is demonstrated. The enzyme immobilization is done on a planar gold gate electrode using 3-mercapto propionic acid as the linker molecule. The sensor showed good sensing capability as a sensor for the neurotransmitter acetylcholine, with a sensitivity of 5.7 μA/decade, and d...

Glucose and lactate enzyme electrodes have been fabricated through the deposition of an anionic self-assembled monolayer and subsequent redox polymer/enzyme electrostatic complexation on gold substrates. These surfaces were functionalized with a negative charge using 11-mercaptoundecanoic acid (MUA), followed by alternating immersions in cationic redox polymer solutions and anionic glucose oxid...

Since 1962 when Clark introduced the enzyme electrode, research has been intense for a robust implantable glucose sensor. An alternative "optical affinity sensor" was introduced by Jerome Schultz in 1979. The evolution of this sensor technology into a new methodology is reviewed. The approach integrates a variety of disparate concepts: the selectivity of immunoassays-selectivity for glucose was...

An enzyme-metal-insulator-silicon (EMIS) structured chemical sensor based on photovoltage technology is constructed for potentiometric biosensing of glucose in a flow-injection analysis (FIA) system. To enhance the sensibility of the sensor to glucose, an ultra-thin (60 nm) film of polypyrrole (PPy)-glucose oxidase (GOD) is formed as the glucose-sensitive membrane through a simple electropolyme...

The Mn3O4@ZIF-67 (zeolite imidazole framework) composite material on carbon cloth (Mn3O4@ZIF-67/CC) was successfully synthesized by a one-step hydrothermal method and used as an enzyme-free glucose sensor. Benefit from the oxidation of manganese oxide porous structure ZIF material, Mn3O4@ZIF-67/CC sensor showed good sensing performance with excellent sensitivity 3421.0 μA mM−1 cm−2, wide linear...

A potentiometric microbial biosensor for the direct measurement of organophosphate (OP) nerve agents was developed by modifying a pH electrode with an immobilized layer of Escherichia coli cells expressing organophosphorus hydrolase (OPH) on the cell surface. OPH catalyzes the hydrolysis of organophosporus pesticides to release protons, the concentration of which is proportional to the amount o...

Fluorescent conjugated polyelectrolytes with pendant ionic sulfonate and carboxylate groups are used to sense protease activity. Inclusion of the fluorescent conjugated polyelectrolyte into the assay scheme leads to amplification of the sensory response. The sensing mechanism relies on an electrostatic interaction between the conjugated polyelectrolyte and a peptide substrate that is labeled wi...

Reliable and accurate in situ sensors capable of detecting quantifying troublesome marine biofilms on metallic surfaces are increasingly necessary. A 0.2 mm diameter gold electrochemical sensor was fully characterized using cyclic voltammetry abiotic biotic artificial seawater media within a continuous culture flow cell to detect the growth development an aerobic Pseudoalteromonas sp. biofilm. ...

This paper is focused on a novel design of stepped diaphragm for MEMS capacitive pressure sensor used in tire pressure monitoring system. The structure of sensor diaphragm plays a key role for determining the sensitivity of the sensor and the non-linearity of the output.First the structures of two capacitive pressure sensors with clamped square flatdiaphragms, with different thicknesses are inv...