title: Impedimetric monitoring of apoptosis using cytochrome-aptamer bioconjugated silver nanocluster.
abstract: It is well known that cytochrome c (Cyt c) is a crucial death regulator that triggers programmed cell death, apoptosis. Here, we report on the successful application of an aptamer bioconjugated nanoclusters for the detection of apoptosis based on release of cytochrome c from mitochondria in lysates human embryonic kidney cells HEK293T. The aptamer-conjugated silver nanoclusters (Apt@AgNCs) were synthesized and immobilized on gold electrode for impedimetric detection of Cyt c over the range of 0.15-375nM. It was found that the presence of Ag(I) ions shell at the surface of prepared NCs could increase their affinity to the donor groups (COO-and some amine groups in its deprotonated form, NH2) of cysteine attached on the gold electrode surface. The use of NCs, which play the role of conductive holders, established a simple immobilization procedure based on a low cost non-functionalized DNA sequence. To diminish the probable nonspecific impedance changes and decrease time of measurement, a rapid single frequency measurements (SFM) was assessed based on recording total impedance |Z| in different individual frequencies.
authors.affiliation: Department of Chemistry, Razi University, Kermanshah, Iran. Electronic address: mshamsipur@yahoo.com.
authors.forename: Mojtaba
authors.initials: M
authors.lastname: Shamsipur
authors.affiliation: Department of Chemistry, Razi University, Kermanshah, Iran. Electronic address: afshin.pashabadi@gmail.com.
authors.forename: Afshin
authors.initials: A
authors.lastname: Pashabadi
authors.affiliation: Department of Chemistry, Tarbiat Modares University, Tehran, Iran.
authors.forename: Fatemeh
authors.initials: F
authors.lastname: Molaabasi
authors.affiliation: Department of Biochemistry, Faculty of Biological Sciences, Tarbiat Modares University, Tehran, Iran.
authors.forename: Saman
authors.initials: S
authors.lastname: Hosseinkhani
mesh_terms: D017209:Apoptosis; D052157:Aptamers, Nucleotide / Q000737:chemistry*; D015374:Biosensing Techniques / Q000379:methods*; D045304:Cytochromes c / Q000032:analysis*; D017097:Electric Impedance; D004566:Electrodes; D057809:HEK293 Cells; D006801:Humans; D053768:Metal Nanoparticles / Q000737:chemistry* / Q000648:ultrastructure; D008958:Models, Molecular; D012834:Silver / Q000737:chemistry*
chemical_list: D052157:Aptamers, Nucleotide; D012834:Silver; D045304:Cytochromes c
keywords: Apoptosis; Aptamer-conjugated silver nanoclusters; Cytochrome c; Impedimetric detection