Introducing a new method for evaluation of the interaction between an antigen and an antibody: single frequency impedance analysis for biosensing systems.
This paper illustrates the application of an antibody, anti-parathyroid hormone (anti-PTH), as a bioreceptor in a biosensor system for the first time, and demonstrates how this biosensor can be used in parathyroid hormone (PTH) determination. The interaction between the biosensor and parathyroid hormone was firstly investigated by a novel electrochemical method, single frequency impedance analysis. The biosensor was based on the gold electrode modified by cysteine self-assembled monolayers. Anti-PTH was covalently immobilized onto cysteine layer by using an EDC/NHS couple. The immobilization of anti-PTH was monitored by cyclic voltammetry and electrochemical impedance spectroscopy techniques. The performance of the biosensor was evaluated in terms of linearity, sensitivity, repeatability and reproducibility, after a few important optimization studies were carried out. In particular, parathyroid hormone was detected within a linear range of 10-60 fg/mL. Kramers-Kronig transform was also performed on the impedance data. The specificity of the biosensor was also evaluated. The biosensor was validated by using a complementary reference technique. Lastly the developed biosensor was used to monitor PTH levels in artificial serum samples.
Namık Kemal University, Faculty of Science and Arts, Chemistry Department, Biochemistry Division, Tekirdağ, Turkey.
Burcu
B
Özcan
Namık Kemal University, Faculty of Science and Arts, Chemistry Department, Biochemistry Division, Tekirdağ, Turkey.
Burçak
B
Demirbakan
Namık Kemal University, Faculty of Science and Arts, Chemistry Department, Biochemistry Division, Tekirdağ, Turkey.
Gülden
G
Yeşiller
Namık Kemal University, Faculty of Science and Arts, Chemistry Department, Biochemistry Division, Tekirdağ, Turkey. Electronic address: msezginturk@hotmail.com.
Mustafa Kemal
MK
Sezgintürk
D000906:Antibodies / Q000737:chemistry; D000937:Antigen-Antibody Reactions; D015374:Biosensing Techniques; D003545:Cysteine / Q000737:chemistry; D058266:Dielectric Spectroscopy / Q000379:methods*; D017097:Electric Impedance; D004563:Electrochemistry / Q000379:methods; D004566:Electrodes; D006046:Gold / Q000737:chemistry; D006801:Humans; D010084:Oxidation-Reduction; D010281:Parathyroid Hormone / Q000032:analysis / Q000097:blood; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity
D000906:Antibodies; D010281:Parathyroid Hormone; D006046:Gold; D003545:Cysteine
Anti-parathyroid hormone; Biomarker; Biosensor; Parathyroid hormone; Parathyroidism; Single frequency impedance