A possibility of detection of the non-charge based analytes using ultra-thin body field-effect transistors

• Published in: Biosensors & bioelectronics 2008-07, Vol.23 (12), p.1883-1886
• Main Authors: Sheu, J.-T., Chen, C.C., Chang, K.S., Li, Y.-K.
• Format: Article
• Language: English
• Subjects: 19-Norandrostendione; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Electrochemistry - instrumentation; Electrochemistry - methods; Equipment Design; Equipment Failure Analysis; Feasibility Studies; Fundamental and applied biological sciences. Psychology; Gold nanoparticles; Methods. Procedures. Technologies; Miniaturization; N-[3-(Trimethoxysilyl)propyl]ethylenediamine; Static Electricity; Transistors, Electronic; Ultra-thin body field-effect transistor; Various methods and equipments; Δ 5-3-Ketosteroid isomerase
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2008.02.024

Ultra-thin body of p-type field-effect transistors were developed as transducer for biosensors. Changes of conductance resulted from the changes of the surface potentials of ultra-thin body field-effect transistors (UTB-FETs) due to surface chemical modifications were demonstrated. The channel surface of UTB-FETs were modified with N-[3-(trimethoxysilyl)propyl]ethylenediamine (AEAPTMS) and then gold nanoparticles (AuNPs) to immobilize the bio-component, the genetically engineered Δ 5-3-ketosteroid isomerase (Art_KSI) or the Art_KSI conjugated with charged reporter (Art_KSI_mA51). The binding of charge-based molecules or nanoparticles has been demonstrated to strongly affect the conductivity of UTB-FETs; the increase or decrease of the conductance depends on the polarity of the immobilized molecules or nanoparticles. A new protocol involving the detection of a non-charged analyte relied on the competitive binding of analyte (19-norandrostendione) and a charged reporter (mA51) with KSI. When exposed to a 19-norandrostendione solution (10 μM), the conductance of Art_KSI_mA51-modified UTB-FET increased by 265 nS (∼12%). On the other hand, conductance of Art_KSI-modified UTB-FET showed no distinct change under the same detection conditions.