Premium
Direct Electrochemical Aptamer‐Based Detection of Digoxin
Author(s) -
Wijesinghe Mahadurage Sachintha,
Ngwa Wilfred,
Chow KwokFan
Publication year - 2020
Publication title -
chemistryselect
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.437
H-Index - 34
ISSN - 2365-6549
DOI - 10.1002/slct.202000286
Subject(s) - digoxin , aptamer , methylene blue , electrode , chemistry , therapeutic index , linear range , atrial flutter , electrochemistry , therapeutic drug monitoring , atrial fibrillation , chromatography , pharmacology , detection limit , cardiology , heart failure , drug , medicine , biochemistry , biology , microbiology and biotechnology , photocatalysis , catalysis
Abstract Here we report a signal‐on electrochemical aptamer‐based (E‐AB) sensor for the detection of digoxin at clinically relevant levels. Digoxin is a plant‐based medication that is prescribed to treat patients with congestive heart failure and chronic atrial fibrillation and atrial flutter. Digoxin has a narrow therapeutic range index of between 0.5 ng/mL and 2.0 ng/mL. The aptamer used in this study is a 50‐base DNA oligonucleotide that has been proven to have high affinity toward digoxin. One end of the aptamer is immobilized on a gold electrode surface and the other end is tagged with a methylene blue molecule, which is used as a redox label. Like other signal‐on E‐AB sensors, once the target binds to the aptamer‐modified electrode, the methylene blue reduction current increases. The developed E‐AB digoxin sensor provides a distinct and amplified peak current response in the therapeutic range of 0.5 ng/mL to 2.0 ng/mL in a phosphate buffer saline solution. The advantage of this detection method is that it allows an aptamer‐modified electrode to perform single‐step and reagentless sensing. We suggest this approach as a conceptual pathway to point‐of‐care E‐AB digoxin sensor design.