title: Oriented immobilization of His-tagged protein on a redox active thiol derivative of DPTA-Cu(II) layer deposited on a gold electrode--the base of electrochemical biosensors.
abstract: This paper concerns the development of an electrochemical biosensor for the determination of Aβ(16-23') and A(β1-40) peptides. The His-tagged V and VC1 domains of Receptor for Advanced Glycation end Products (RAGE) immobilized on a gold electrode surface were used as analytically active molecules. The immobilization of His6-RAGE domains consists of: (i) formation of a mixed layer of N-acetylcysteamine (NAC) and the thiol derivative of pentetic acid (DPTA); (ii) complexation of Cu(II) by DPTA; (iii) oriented immobilization of His6-RAGE domains via coordination bonds between Cu(II) sites from DPTA-Cu(II) complex and imidazole nitrogen atoms of a histidine tag. Each modification step was controlled by cyclic voltammetry (CV), Osteryoung square-wave voltammetry (OSWV), and atomic force microscopy (AFM). The applicability of the proposed biosensor was tested in the presence of human plasma, which had no influence on its performance. The detection limits for Aβ(1-40) determination were 1.06 nM and 0.80 nM, in the presence of buffer and human plasma, respectively. These values reach the concentration level of Aβ(1-40) which is relevant for determination of its soluble form in human plasma, as well as in brain. This indicates the promising future application of biosensor presented for early diagnosis of neurodegenerative diseases.
authors.affiliation: Institute of Animal Reproduction and Food Research of Polish Academy of Sciences, Tuwima 10, Olsztyn 10-748, Poland. e.mikula@pan.olsztyn.pl
authors.forename: Edyta
authors.initials: E
authors.lastname: Mikuła
authors.forename: Magdalena
authors.initials: M
authors.lastname: Sulima
authors.forename: Ilona
authors.initials: I
authors.lastname: Marszałek
authors.forename: Aleksandra
authors.initials: A
authors.lastname: Wysłouch-Cieszyńska
authors.forename: Peter
authors.initials: P
authors.lastname: Verwilst
authors.forename: Wim
authors.initials: W
authors.lastname: Dehaen
authors.forename: Jerzy
authors.initials: J
authors.lastname: Radecki
authors.forename: Hanna
authors.initials: H
authors.lastname: Radecka
mesh_terms: D016229:Amyloid beta-Peptides / Q000032:analysis*; D015374:Biosensing Techniques / Q000295:instrumentation*; D020099:Coated Materials, Biocompatible / Q000138:chemical synthesis; D003217:Conductometry / Q000295:instrumentation*; D003300:Copper / Q000737:chemistry; D004566:Electrodes; D004867:Equipment Design; D019544:Equipment Failure Analysis; D006046:Gold / Q000737:chemistry*; D006639:Histidine / Q000737:chemistry*; D010084:Oxidation-Reduction; D004369:Pentetic Acid / Q000737:chemistry*; D010446:Peptide Fragments / Q000032:analysis*; D015203:Reproducibility of Results; D012680:Sensitivity and Specificity; D013438:Sulfhydryl Compounds / Q000737:chemistry
chemical_list: D016229:Amyloid beta-Peptides; D020099:Coated Materials, Biocompatible; D010446:Peptide Fragments; D013438:Sulfhydryl Compounds; C078592:amyloid beta-protein (1-40); D006639:Histidine; D006046:Gold; D003300:Copper; D004369:Pentetic Acid