title: Novel electrical detection of label-free disease marker proteins using piezoresistive self-sensing micro-cantilevers.
abstract: We report an electro-mechanical biosensor for electrical detection of proteins with disease markers using self-sensing piezoresistive micro-cantilevers. Electrical detection, via surface stress changes, of antigen-antibody (Ag-Ab) specific binding was accomplished through a direct nano-mechanical response of micro-fabricated self-sensing micro-cantilevers. A piezoresistive sensor measures the film resistance variation with respect to surface stress caused by biomolecules specific binding. When specific binding occurred on a functionalized Au surface, surface stress was induced throughout the cantilever, resulting in cantilever bending and resistance change of the piezoresistive layer. The cantilever biosensors were used for the detection of prostate specific antigen (PSA) and C-reactive proteins (CRP), which are a specific marker of prostate cancer and cardiac disease. From the above experiment, it was revealed that the sensor output voltage was proportional to the injected antigen concentration (without antigen, 10 ng/ml, 100 ng/ml, 1 microg/ml). PSA and CRP antibodies were found to be very specific for their antigens, respectively. This indicated that the self-sensing micro-cantilever approach is beneficial for detecting disease markers, and our piezoresistive micro-cantilever sensor system is applicable to miniaturized biosensor systems.
authors.affiliation: Microsystem Research Center, Korea Institute of Science and Technology (KIST), Seoul 136-791, Republic of Korea.
authors.forename: Kyung Wook
authors.initials: KW
authors.lastname: Wee
authors.forename: Ghi Yuun
authors.initials: GY
authors.lastname: Kang
authors.forename: Jaebum
authors.initials: J
authors.lastname: Park
authors.forename: Ji Yoon
authors.initials: JY
authors.lastname: Kang
authors.forename: Dae Sung
authors.initials: DS
authors.lastname: Yoon
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Park
authors.forename: Tae Song
authors.initials: TS
authors.lastname: Kim
mesh_terms: D015415:Biomarkers / Q000097:blood; D014408:Biomarkers, Tumor / Q000097:blood; D015374:Biosensing Techniques / Q000295:instrumentation* / Q000379:methods; D001798:Blood Proteins / Q000032:analysis; D002097:C-Reactive Protein / Q000032:analysis*; D017097:Electric Impedance; D004563:Electrochemistry / Q000295:instrumentation* / Q000379:methods; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006331:Heart Diseases / Q000097:blood* / Q000175:diagnosis; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation* / Q000379:methods; D008297:Male; D008904:Miniaturization; D017430:Prostate-Specific Antigen / Q000097:blood*; D011471:Prostatic Neoplasms / Q000097:blood* / Q000175:diagnosis; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D014159:Transducers
chemical_list: D015415:Biomarkers; D014408:Biomarkers, Tumor; D001798:Blood Proteins; D002097:C-Reactive Protein; D017430:Prostate-Specific Antigen