Designing a label‐free electrochemical aptasensor based on polypyrrole‐<scp>l</scp>‐cysteine‐reduced graphene oxide nanocomposite for detection of 25‐hydroxyvitamin D<sub>3</sub>
Maryam Heydari, Nadereh Rahbar, Aida Gholoobi, Arash Mohammadinejad, Majid Rezayi
Abstract
Abstract Reliable and precise quantification of 25‐hydroxyvitamin D 3 in clinical samples is vital because vitamin D 3 deficiency lead to several disorders, such as mental illness, osteoporosis, and coronavirus disease. Herein, we report the fabrication of a novel electrochemical aptasensor using a nanocomposite, including reduced graphene oxide, pyrrole, and l ‐cysteine, for the sensitive detection of 25‐hydroxyvitamin D 3 . Subsequently, the aptamer of 25‐hydroxyvitamin D 3 was immobilized on the surface of the modified electrode. Differential pulse voltammetry signals were utilized for studying the binding and measurement of 25‐hydroxyvitamin D 3 based on the oxidation peak. Under the optimum conditions, the designed electrochemical aptasensor exhibited a linear detection range of 0.001–150 nM, with a limit of detection of 0.006 nM. Furthermore, the proposed aptasensor selectively detected 25‐hydroxyvitamin D 3 compared to other analogs. Moreover, this aptasensor was successfully applied for the detection of 25‐hydroxyvitamin D 3 in human serum samples, which were quantified by the enzyme‐linked immunosorbent assay method. The acceptable recoveries of 82.67%–111.07% demonstrated that this proposed electrochemical aptasensor can be a promising alternative for clinical methods of vitamin D determination.