An FET-type charge sensor for highly sensitive detection of DNA sequence

Electrochemical and Magnetic Technologies for Bio Applications

“…This integrated circuit (IC) technology is a promising technique for DNA chip systems in addition to biochip systems. Electric (or electrochemical) detection of DNA is also a promising technique; however, research on electric DNA sensors has focused more on label-free DNA hybridization [89][90][91][92][93] because electric detection shows good performance at qualitative assays, such as point-of-care testing, but not in quantitative assays as compared with fluorescence detection. In this section, miniaturized photodetectors towards DNA chip technology are summarized (Table 11.1).…”

Electrochemical Aptasensors

“…Upon changing the potential of the gate electrode as a result of a biosensing event, the source-to-drain current is perturbed and its value can be retained either by changing the V ds potential or by altering the potential between the reference electrode and the source, V gs , for compensation of the potential changes on the gate. For example, alteration of the charge (and thus the potential) on the gate of the ISFETs upon hybridization of the complementary nucleic acid to the gate-confined DNA was used for the label-free reagentless detection of DNA (Fritz et al, 2002;Kim et al, 2004;Shin et al, 2004;Uslu et al, 2004;Sakata and Miyahara, 2005). Binding of a low-molecular-weight substrate (e.g., adenosine) to its aptamer was followed by an ion-selective field-effect transistor, and this demonstrated the development of a label-free aptasensor (Zayats et al, 2006).…”

Chemical and Biological Field‐Effect Sensors for Liquids—A Status Report

“…Therefore, in recent years, a considerable research effort has been devoted to the label-free electronic detection of biomolecules (DNA, proteins) by their intrinsic molecular charge using FEDs. [45][46][47][48][49][50][51][52][53][54][55][56][57][58][59][60] In most cases, the experimentally observed sensor response is interpreted in a way that during the binding event (hybridization of immobilized single-strand DNA (ssDNA) cDNA ssDNA p-Si with its complementary target molecule (cDNA); see Figure 2) the charge associated with the target molecule effectively changes the charge applied to the gate of the FED. As a result, the operating characteristics of the FED, that is, the flat-band voltage and capacitance of the EIS sensor or the threshold voltage and drain current of the FET device, will also change.…”