Nasrin Afsarimanesh: School of Engineering and Advanced Technology, Massey University, Palmerston North 4442, New Zealand. afsarimanesh@yahoo.com.
Asif I Zia: School of Engineering and Advanced Technology, Massey University, Palmerston North 4442, New Zealand. a.i.zia@me.com.
Subhas Chandra Mukhopadhyay: Department of Engineering, Macquarie University, North Ryde NSW 2109, Australia. subhas.mukhopadhyay@mq.edu.au.
Marlena Kruger: Institute of Food Science and Technology, Massey University, Palmerston North 4442, New Zealand. M.C.Kruger@massey.ac.nz.
Pak-Lam Yu: School of Engineering and Advanced Technology, Massey University, Palmerston North 4442, New Zealand. P.Yu@massey.ac.nz.
Jurgen Kosel: Sensing, Magnetism and Microsystems Group, King Abdullah University of Science and Technology, Thuwal 23955-6900, Saudi Arabia. jurgen.kosel@kaust.edu.sa.
Zoltan Kovacs: Department of Physics and Control, Faculty of Food Science, Szent István University, Budapest H-1118, Hungary. zoltan.kovacs@chemometrics.hu.
The objective of this paper is to report a novel non-invasive, real-time, and label-free smart assay technique for the prognostic detection of bone loss by electrochemical impedance spectroscopy (EIS). The proposed system incorporated an antibody-antigen-based sensor functionalization to induce selectivity for the C-terminal telopeptide type one collagen (CTx-I) molecules-a bone loss biomarker. Streptavidin agarose was immobilized on the sensing area of a silicon substrate-based planar sensor, patterned with gold interdigital electrodes, to capture the antibody-antigen complex. Calibration experiments were conducted with various known CTx-I concentrations in a buffer solution to obtain a reference curve that was used to quantify the concentration of an analyte in the unknown serum samples. Multivariate chemometric analyses were done to determine the performance viability of the developed system. The analyses suggested that a frequency of 710 Hz is the most discriminating regarding the system sensitivity. A detection limit of 0.147 ng/mL was achieved for the proposed sensor and the corresponding reference curve was linear in the range of 0.147 ng/mL to 2.669 ng/mL. Two sheep blood samples were tested by the developed technique and the results were validated using enzyme-linked immunosorbent assay (ELISA). The results from the proposed technique match those from the ELISA.
