title: Dendrimer enriched single-use aptasensor for impedimetric detection of activated protein C.
abstract: A novel impedimetric aptasensor for detection of human activated protein C (APC) was introduced for the first time in the present study. An enhanced sensor response was obtained using poly(amidoamine) (PAMAM) dendrimer having 16 succinamic acid surface groups (generation 2, G2-PS), that was modified onto the surface of screen printed graphite electrode (G2-PS/SPE). An amino modified DNA aptamer was then immobilized onto the surface of G2-PS modified SPE. The selective interaction of APT with its cognate protein, APC was investigated using different electrochemical techniques; differential pulse voltammetry (DPV), cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The microscopic characterization was consecutively performed before/after each modification/interaction step using scanning electron microscopy (SEM) and atomic force microscopy (AFM). The selectivity of aptasensor was tested in the presence of numerous proteins; protein C, thrombin, bovine serum albumin, factor Va and chromogenic substrate in different buffer mediums. The APC detection in the artificial serum; fetal bovine serum (FBS) was also performed impedimetrically. This dendrimer modified aptasensor technology brings several advantages: being single-use, fast screening with low-cost per measurement and resulting in sensitive detection of APC with the detection limits of 0.74 μg/mL (0.46 pmol in 35 μL sample) in buffer medium, and 2.03 μg/mL (1.27 pmol in 35 μL sample) in serum.
authors.affiliation: Ege University, Faculty of Pharmacy, Analytical Chemistry Department, 35100 Bornova, Izmir, Turkey; Ege University, The Institute of Natural and Applied Sciences, Biotechnology Department, 35100 Bornova, Izmir, Turkey. Electronic address: arzume@hotmail.com.
authors.forename: Arzum
authors.initials: A
authors.lastname: Erdem
authors.affiliation: Ege University, Faculty of Pharmacy, Analytical Chemistry Department, 35100 Bornova, Izmir, Turkey; Ege University, The Institute of Natural and Applied Sciences, Biotechnology Department, 35100 Bornova, Izmir, Turkey.
authors.forename: Gulsah
authors.initials: G
authors.lastname: Congur
mesh_terms: D052157:Aptamers, Nucleotide / Q000737:chemistry*; D050091:Dendrimers / Q000737:chemistry*; D055664:Electrochemical Techniques / Q000379:methods*; D004566:Electrodes; D006108:Graphite / Q000737:chemistry; D006801:Humans; D018625:Microscopy, Atomic Force; D010084:Oxidation-Reduction; D011486:Protein C / Q000032:analysis*
chemical_list: D052157:Aptamers, Nucleotide; D050091:Dendrimers; D011486:Protein C; D006108:Graphite
keywords: Activated protein C (APC); DNA aptamer; Electrochemical impedance spectroscopy; Poly(amidoamine) dendrimer; Screen printed graphite electrode