title: Single-walled carbon nanotube based transparent immunosensor for detection of a prostate cancer biomarker osteopontin.
abstract: Osteopontin (OPN) is involved in almost all steps of cancer development, and it is being investigated as a potential biomarker for a diagnosis and prognosis of prostate cancer. Here, we report a label-free, highly sensitive and transparent immunosensor based on single-walled carbon nanotubes (SWCNTs) for detection of OPN. A high density of COOH functionalized SWCNTs was deposited between two gold/indium tin oxide electrodes on a glass substrate by dielectrophoresis. Monoclonal antibodies specific to OPN were covalently immobilized on the SWCNTs. Relative resistance change of the immunosensors was measured as the concentration of OPN in phosphate buffer saline (PBS) and human serum was varied from 1 pg mL(-1) to 1 μg mL(-1) for different channel lengths of 2, 5, and 10 μm, showing a highly linear and reproducible behavior (R(2)>97%). These immunosensors were also specific to OPN against another test protein, bovine serum albumin, PBS and human serum, showing that a limit of detection for OPN was 0.3 pg mL(-1). This highly sensitive and transparent immunosensor has a great potential as a simple point-of-care test kit for various protein biomarkers.
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Abhinav
authors.initials: A
authors.lastname: Sharma
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Seongkyeol
authors.initials: S
authors.lastname: Hong
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea.
authors.forename: Renu
authors.initials: R
authors.lastname: Singh
authors.affiliation: School of Mechanical and Nuclear Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea; Department of Biomedical Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea; School of Materials Science and Engineering, Ulsan National Institute of Science and Technology (UNIST), Ulsan 689-798, Republic of Korea. Electronic address: jjang@unist.ac.kr.
authors.forename: Jaesung
authors.initials: J
authors.lastname: Jang
mesh_terms: D014408:Biomarkers, Tumor / Q000032:analysis* / Q000097:blood; D015374:Biosensing Techniques / Q000379:methods*; D004560:Electricity; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D007118:Immunoassay / Q000379:methods*; D057230:Limit of Detection; D008297:Male; D008958:Models, Molecular; D008968:Molecular Conformation; D037742:Nanotubes, Carbon / Q000737:chemistry*; D053495:Osteopontin / Q000032:analysis*; D011471:Prostatic Neoplasms / Q000097:blood; D017971:Tin Compounds / Q000737:chemistry
chemical_list: D014408:Biomarkers, Tumor; D037742:Nanotubes, Carbon; D017971:Tin Compounds; D053495:Osteopontin; C109984:indium tin oxide; D006046:Gold
keywords: Cancer; Carbon nanotubes; Dielectrophoresis; Field effect transistor sensors; Osteopontin; Transparent sensor