title: EIS-based biosensor for ultra-sensitive detection of TNF-α from non-diluted human serum.
abstract: Serum background is a critical issue for biosensor development as it interferes with the detection of target molecules and may give rise to false positive signal. We present here highly sensitive and selective TNF-α biosensor which is able to detect TNF-α from non-diluted human serum using magnetic bead coupled antibody and electrochemical impedance spectroscopy (EIS) techniques. The process is designed to detect TNF-α from human serum in three stages; (1) abundant protein backgrounds are depleted from the serum using magnetic bead coupled albumin and IgG antibodies, (2) after background depletion TNF-α is captured using magnetic bead coupled TNF-α antibody, and (3) the captured TNF-α is eluted from the magnetic beads and measured using EIS technique in which comb structured gold microelectrodes array (CSGM) is utilized to enhance the detection sensitivity. The system is able to achieve the limit of detection (LOD) at 1 pg/ml (57 fM) and a linear relationship between increasing TNF-α concentrations and charge-transfer resistance in a dynamic range of 1-1000 pg/ml.
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore. Electronic address: kongsupholp@ime.a-star.edu.sg.
authors.forename: Patthara
authors.initials: P
authors.lastname: Kongsuphol
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore.
authors.forename: Hui Hwee
authors.initials: HH
authors.lastname: Ng
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore; School of Chemistry and Institute for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
authors.forename: Joanna P
authors.initials: JP
authors.lastname: Pursey
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore.
authors.forename: Sunil K
authors.initials: SK
authors.lastname: Arya
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore.
authors.forename: Chee Chung
authors.initials: CC
authors.lastname: Wong
authors.affiliation: School of Chemistry and Institute for Life Sciences, University of Southampton, Highfield, Southampton SO17 1BJ, UK.
authors.forename: Eugen
authors.initials: E
authors.lastname: Stulz
authors.affiliation: Institute of Microelectronics, A(⁎)STAR (Agency for Science Technology and Research), 11 Science Park Road, Singapore Science Park II, 117685, Singapore.
authors.forename: Mi Kyoung
authors.initials: MK
authors.lastname: Park
mesh_terms: D055910:Antibodies, Immobilized / Q000737:chemistry; D015374:Biosensing Techniques / Q000379:methods*; D058266:Dielectric Spectroscopy / Q000379:methods; D004566:Electrodes; D006801:Humans; D018189:Immunomagnetic Separation; D057230:Limit of Detection; D014409:Tumor Necrosis Factor-alpha / Q000097:blood*
chemical_list: D055910:Antibodies, Immobilized; D014409:Tumor Necrosis Factor-alpha
keywords: EIS; Electrochemical impedance spectroscopy; Non-diluted serum; Serum; TNF-α; Tumor necrosis factor