An Ultrasensitive Silicon-Based Electrolyte-Gated Transistor for the Detection of Peanut Allergens

Abstract

The highly sensitive detection of peanut allergens (PAs) using silicon-based electrolyte-gated transistors (Si-EGTs) was demonstrated. The Si-EGT was made using a top-down technique. The fabricated Si-EGT showed excellent intrinsic electrical characteristics, including a low threshold voltage of 0.7 V, low subthreshold swing of <70 mV/dec, and low gate leakage of <10 pA. Surface functionalization and immobilization of antibodies were performed for the selective detection of PAs. The voltage-related sensitivity (SV) showed a constant behavior from the subthreshold regime to the linear regime. The current-related sensitivity (SI) was high in the subthreshold regime and then significantly decreased as the drain current increased. The limit of detection (LOD) was calculated to be as low as 25 pg/mL based on SI characteristics, which is the lowest value reported to date in the literature for various sensor methodologies. The Si-EGT showed selective detection of PA through a non-specific control test. These results confirm that Si-EGT is a high-sensitivity and low-power biosensor for PA detection.

Application performance of silicon-based different biosensors

“…Kim et al constructed a top-down technique silicon-based electrolyte-gated transistors (Si-EGTs) to label-free analyze peanut allergens (PAs): Arachis hypogaea 1 (Ara h1) and Ara h3 extreme sensitively [10]. The introduction of EGT can enhance the binding probability of biomolecules, resulting in an amplification of the absolute sensing current.…”

Polymeric integration of structure-switching aptamers on transistors for histamine sensing

“…Electrolyte-gated eld-effect transistors (EG-FETs) are becoming the transducer of choice for many biosensors due to their superior electronic properties and intrinsic signal amplication, which allows the sensitive detection of small molecules. [1][2][3][4] The formation of an electric double layer at the electrolyte/ semiconductor interface of EG-FETs leads to a large gate capacitance, which enables device functionality below ±1 V, a necessary condition when using waterbased electrolytes; electrochemical decomposition occurs at 1.23 V. 5 Among the channel materials for EG-FETs, carbon nanotubes (CNTs) have demonstrated high potential for sensitive small-molecule biosensing, due to nanometric dimensions comparable to analytes of interest. With diameters that vary from 0.4 nm to 100 nm and a length up to tens of micrometers, CNTs have high aspectratios and subsequently high surface areas available for functionalization with bioreceptors.…”

“…19 While this functionalization strategy provides a durable bond, the procedure of generating functional groups on the CNT surfaces (e.g., the use of strong oxidizing agents) can generate defects in the nanotube structures. Therefore, noncovalent functionalization is favorable, as the carbon atoms in the CNTs keep their sp 2 hybridization and maintain their optimal electrical properties. 8,20 Noncovalent modications involve physical adsorption of biorecognition elements onto the CNT surface through p-p, hydrophobic, or electrostatic interactions.…”

Highly Sensitive Detection of Urea Using Si Electrolyte-Gated Transistor with Low Power Consumption

“…However, the inherent interface between the gate and membrane generates additional parasitic capacitance and resistance, which worsens the sensitivity and reproducibility. More recently, electrolytegated FETs (EGTs) that use a functionalized gate electrode as the sensing surface have been developed [18][19][20][21][22]. The larger gate area, typically one order of magnitude larger than the channel area, is beneficial to achieve higher receptor density, thus enhancing output signals and reducing performance variations, which is crucial for the commercialization of BioFETs.…”