title: Sensitivity improvement of an electrical sensor achieved by control of biomolecules based on the negative dielectrophoretic force.
abstract: Effective control of nano-scale biomolecules can enhance the sensitivity and limit of detection of an interdigitated microelectrode (IME) sensor. Manipulation of the biomolecules by dielectrophoresis (DEP), especially the negative DEP (nDEP) force, so that they are trapped between electrodes (sensing regions) was predicted to increase the binding efficiency of the antibody and target molecules, leading to a more effective reaction. To prove this concept, amyloid beta 42 (Aβ42) and prostate specific antigen (PSA) protein were respectively trapped between the sensing region owing to the nDEP force under 5V and 0.05V, which was verified with COMSOL simulation. Using the simulation value, the resistance change (ΔR/Rb) of the IME sensor from the specific antibody-antigen reaction of the two biomolecules and the change in fluorescence intensity were compared in the reference (pDEP) and nDEP conditions. The ΔR/Rb value improved by about 2-fold and 1.66-fold with nDEP compared to the reference condition with various protein concentrations, and these increases were confirmed with fluorescence imaging. Overall, nDEP enhanced the detection sensitivity for Aβ42 and PSA by 128% and 258%, respectively, and the limit of detection improved by up to 2-orders of magnitude. These results prove that DEP can improve the biosensor's performance.
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea; Department of Electrical Engineering, Korea University,145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Hye Jin
authors.initials: HJ
authors.lastname: Kim
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea.
authors.forename: Jinsik
authors.initials: J
authors.lastname: Kim
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea.
authors.forename: Yong Kyoung
authors.initials: YK
authors.lastname: Yoo
authors.affiliation: Department of Electrical Engineering, Kwangwoon University, 20 Gwangun-ro, Nowon-gu, Seoul 01897, Republic of Korea.
authors.forename: Jeong Hoon
authors.initials: JH
authors.lastname: Lee
authors.affiliation: Department of Electrical Engineering, Korea University,145 Anam-ro, Seongbuk-gu, Seoul 02841, Republic of Korea.
authors.forename: Jung Ho
authors.initials: JH
authors.lastname: Park
authors.affiliation: Center for Biomicrosystems, Korea Institute of Science and Technology (KIST), Hwarang-ro 14-gil 5, Seongbuk-gu, Seoul 02792, Republic of Korea. Electronic address: kshwang@kist.re.kr.
authors.forename: Kyo Seon
authors.initials: KS
authors.lastname: Hwang
mesh_terms: D016229:Amyloid beta-Peptides / Q000032:analysis; D015374:Biosensing Techniques / Q000295:instrumentation*; D004560:Electricity; D004586:Electrophoresis / Q000295:instrumentation*; D004867:Equipment Design; D006801:Humans; D007118:Immunoassay / Q000295:instrumentation; D008839:Microelectrodes; D010446:Peptide Fragments / Q000032:analysis; D017430:Prostate-Specific Antigen / Q000032:analysis
chemical_list: D016229:Amyloid beta-Peptides; D010446:Peptide Fragments; C075222:amyloid beta-protein (1-42); D017430:Prostate-Specific Antigen
keywords: Dielectrophoresis; Electrical sensor; Immunochemical method; Limit of detection; Sensitivity