Ferrocene-functionalized SWCNT for electrochemical detection of T4 polynucleotide kinase activity

Carbon Nanostructures for Tagging in Electrochemical Biosensing: A Review

“…The resulting assay also allowed a robust discrimination between the perfect match and a three-base mismatch sequence and a LOD of 1 × 10 −16 mol in 60 µL full-length (491 bp) DNA oncogene, which enabled the PCR-free detection of target transcripts using only 65 ng of mRNA extracted from the p185 BCR-ABL-positive human leukemic SUP-B15 cell line. Reprinted from [7] with permission.…”

“…The developed method exhibits potential utility in research of interactions between proteins and nucleic acids and provides a diversified platform for a kinase activity assay. A sensitive and label-free electrochemical method involving DNA phosphorylation analysis was developed for determination of T4 polynucleotide kinase (PNK) activity and inhibition by using DNA wrapped aminoferrocene (Fc)-SWCNTs (DNA/Fc-SWCNTs) and Ti 4+ [7]. In this method, a thiolated DNA containing 5 -hydroxyl group was self-assembled onto a gold electrode and used as substrate for PNK.…”

“…The biosensor response was logarithmically related to the target concentration from 10 amol·L −1 to 1 pmol·L −1 , the LOD was 2.8 amol·L −1 , and an excellent selectivity to differentiate single-base mismatched and three-base mismatched sequences of DNA was achieved. A sensitive and label-free electrochemical method involving DNA phosphorylation analysis was developed for determination of T4 polynucleotide kinase (PNK) activity and inhibition by using DNA wrapped aminoferrocene (Fc)-SWCNTs (DNA/Fc-SWCNTs) and Ti 4+ [7]. In this method, a thiolated DNA containing 5′-hydroxyl group was self-assembled onto a gold electrode and used as substrate for PNK.…”

“…Both single-and multi-walled carbon nanotubes (SWCNTs and MWCNTs, respectively) have been used as carriers for loading large amounts of redox mediator molecules [7] or enzyme tags [9] to amplify the electrochemical signals in DNA biosensing. Most of these attempts have focused on enzyme tracers due to the multiple enzymatic turnovers achieved at these bioconjugates which significantly amplify the electrochemical response [8,9].…”

“…Combining signal amplified DNA sensing and electrochemical transduction provides a new avenue to develop ultrasensitive nucleic acid detection technology widely demanded nowadays for routine analysis, point-of-care (POC) and portable device applications [7,8]. Because of their large surface area, excellent biological compatibility and easy functionalization, carbon-based nanomaterials such as carbon nanotubes (CNTs) and graphene have been widely used as excellent carriers for loading numerous signal elements such as enzymes [9], mimic enzymes [10,11], oligonucleotides [12,13] redox reporters [14,15] or combination [7,8]. These elements can greatly amplify the transduction signals of recognition events and simplify the protocols used in electrochemical DNA assays [1,15].…”