Silicon nanowire biosensors for detection of cardiac troponin I (cTnI) with high sensitivity.
We have demonstrated highly sensitive and label-free detection of cardiac troponin I (cTnI), a biomarker for diagnosis of acute myocardial infarction, using silicon nanowire field-effect transistors. A honeycomb-like structure is utilized for nanowire configuration to offer improved electrical performance and increased sensing area. The fabricated devices show n-type behavior with a relatively high ON-OFF current ratio, small sub-threshold swing and low gate leakage current. Monoclonal antibodies for cTnI were covalently immobilized on the nanowire surface and the attachment of antibodies is clearly visualized by atomic force microscope. The sensitivity with various concentrations of buffer solution was also investigated in order to determine the optimal buffer condition. The devices exhibit highest sensitivity under buffer solutions with low ion concentration. In addition, the detection limit of the sensor is as low as ~5 pg/mL, the lowest reported in the literature to date and nearly an order of magnitude smaller than the suggested threshold limit. The fabricated devices demonstrate a good selectivity for detecting cTnI.
Department of Creative IT Engineering and Future IT Innovation Lab., Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Kihyun
K
Kim
Division of IT-Convergence Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Chanoh
C
Park
Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Donghoon
D
Kwon
Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Donghoon
D
Kim
Department of Creative IT Engineering and Future IT Innovation Lab., Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea; NASA Ames Research Center, Moffett Field, CA 94035, USA.
M
M
Meyyappan
Department of Chemical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea.
Sangmin
S
Jeon
Division of IT-Convergence Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea; Department of Electrical Engineering, Pohang University of Science and Technology (POSTECH), Pohang 37673, Republic of Korea. Electronic address: ljs6951@postech.ac.kr.
Jeong-Soo
JS
Lee
D015415:Biomarkers / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation; D003217:Conductometry / Q000295:instrumentation*; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D007118:Immunoassay / Q000295:instrumentation*; D053770:Nanowires / Q000737:chemistry* / Q000648:ultrastructure; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D012825:Silicon / Q000737:chemistry*; D014173:Transistors, Electronic; D019210:Troponin I / Q000032:analysis*
D015415:Biomarkers; D019210:Troponin I; D012825:Silicon
Biosensor; Cardiac troponin I; Debye length; Field-effect transistor; Honeycomb nanowire; Limit of detection