1. Sequence-Independent DNA Adsorption on Few-Layered Oxygen-Functionalized Graphene Electrodes: An Electrochemical Study for Biosensing Application
- Author
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Ishani M Senanayake, Boyd M. Goodson, Mohtashim H. Shamsi, Saikat Talapatra, Poopalasingam Sivakumar, Narges Asefifeyzabadi, and Torrey Holland
- Subjects
Materials science ,Clinical Biochemistry ,Biosensing Techniques ,Electrochemistry ,Redox ,label-free ,Article ,law.invention ,chemistry.chemical_compound ,Adsorption ,law ,inkjet-printing ,Electrodes ,electrochemical biosensors ,Graphene ,General Medicine ,DNA ,Electrochemical Techniques ,Oxygen ,chemistry ,Chemical engineering ,Ionic strength ,trinucleotide repeats ,DNA biosensors ,Graphite ,Differential pulse voltammetry ,Ferricyanide ,graphene electrodes ,Biosensor ,TP248.13-248.65 ,Biotechnology - Abstract
DNA is strongly adsorbed on oxidized graphene surfaces in the presence of divalent cations. Here, we studied the effect of DNA adsorption on electrochemical charge transfer at few-layered, oxygen-functionalized graphene (GOx) electrodes. DNA adsorption on the inkjet-printed GOx electrodes caused amplified current response from ferro/ferricyanide redox probe at concentration range 1 aM–10 nM in differential pulse voltammetry. We studied a number of variables that may affect the current response of the interface: sequence type, conformation, concentration, length, and ionic strength. Later, we showed a proof-of-concept DNA biosensing application, which is free from chemical immobilization of the probe and sensitive at attomolar concentration regime. We propose that GOx electrodes promise a low-cost solution to fabricate a highly sensitive platform for label-free and chemisorption-free DNA biosensing.
- Published
- 2021