A possibility of detection of the non-charge based analytes using ultra-thin body field-effect transistors.
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 Delta(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 microM), the conductance of Art_KSI_mA51-modified UTB-FET increased by 265 nS ( approximately 12%). On the other hand, conductance of Art_KSI-modified UTB-FET showed no distinct change under the same detection conditions.
Sheu
J-T
JT
Institute of Nanotechnology, National Chiao Tung University, 1001 Ta-Hsueh Road, Hsinchu 30050, Taiwan. jtsheu@faculty.nctu.edu.tw
Chen
C C
CC
Chang
K S
KS
Li
Y-K
YK
D015374:Biosensing Techniques / Q000295:instrumentation*; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D005240:Feasibility Studies; D008904:Miniaturization; D055672:Static Electricity; D014173:Transistors, Electronic