With the advantages of small size, reliability, rapid response, compatibility to standard CMOS technology and on-chip signal processing, Ion-Sensitive Field Effect Transistor (ISFET)-based transducers are increasingly being applied in physiological data acquisition and environment monitoring. This paper presents a signal processing Application Specific Integrated Circuit (ASIC) and a discrete t...

The pH values of aqueous solutions are conventionally measured with pH-sensitive electrodes such as glass electrodes or ion-sensitive field-effect transistors (ISFETs) used in conjunction with Ag/AgCl reference electrodes and KCl solutions. The speed of pH measurement with these systems can be deficient, however, as the glass electrode responds slowly during measurements of sample solutions wit...

Measuring pH in glacial meltwaters is challenging, because they are cold, remote, subject to freeze-thaw cycles and have low ionic strength. Traditional methods often perform poorly there; glass electrodes high drift long response times, spectrophotometric techniques unpractical remote environments. Ion selective field effect transistor (ISFET) sensors a promising alternative, proven marine ind...

Acid or base concentrations can be determmed very rapidly by performmg an acid-base titration with coulometncally generated OHor H+ ions at a noble metal actuator electrode m close proximity to the pH-sensitive gate of an ion-sensitive field effect transistor (ISFET) The ISFET is used as the mdicator electrode to detect the eqmvalence point in the titration curve Typical values for the time nee...

The ion-step measuring method was used to determine heparin concentrations in PBS and blood plasma. Heparin is a sulphated polysaccharide which is clinically used as a drug to prevent the clotting of blood. The measuring method is based on detection of changes in charge density in a porous membrane which is deposited on the gate of an ISFET. Protamine was used as affinity ligand in the membrane...

In this paper a short overview is given of the several FET-based sensor devices and the operational principle of the ISFET is summarized. Some of the shortcomings of the FET sensors were circumvented by an alternative operational mode, resulting in a device capable of acid/base concentration determination by coulometric titrant generation as well as in an original pH-static enzyme sensor. A mor...

Graphene, after its first production in 2004 have received lots of attentions from researchers because of its unique properties. High mobility, high sensitivity, high selectivity and high surface area make graphene excellent choice for bio application. One of promising graphene base device that has amazingly high sensitivity is graphene field-effect transistor (GFET). This review selectively su...

Soil testing is the basis for nutrient recommendation and formulated fertilization. This study presented a brief overview of potentiometric electrochemical sensors (ISE and ISFET) for soil NPK detection. The opportunities and challenges for electrochemical sensors in soil testing were

Graphene, after its first production in 2004 have received lots of attentions from researchers because of its unique properties. High mobility, high sensitivity, high selectivity and high surface area make graphene excellent choice for bio application. One of promising graphene base device that has amazingly high sensitivity is graphene field-effect transistor (GFET). This review selectively su...

graphene, after its first production in 2004 have received lots of attentions from researchers because of its unique properties. high mobility, high sensitivity, high selectivity and high surface area make graphene excellent choice for bio application. one of promising graphene base device that has amazingly high sensitivity is graphene field-effect transistor (gfet). this review selectively su...