Molecular dynamic simulation-empowered detection of digoxin by a green aptasensing interface based on pseudo-gold...

Screening digoxin (DIG) dosage in human biofluids is medicolegally important to control its overdose and prevent its severe side effects. In this study, the advanced aptasensing interface has been constructed using a novel nanocomposite as a biocompatible scaffold to anchor Apt strings specific to DIG on the surface under a green methodology. The high-performance nanocomposite consisting of the rice husk (RH)-derived nanosilica and pseudo-gold nanobones (pseudo-AuNBs@RH-derived nanosilica) has been utilized for aptasensor fabrication. Each modification step of the surface has been characterized by the signal change of the ferro/ferri cyanide as the electrochemical probe. The molecular dynamic (MD) computational method has been applied to simulate a visual interaction of Apt with DIG through a conformation-switching assay format from a molecular view to validate DIG binding to Apt. The resulting aptasensor is able to measure DIG quantitatively from 100 fM to 0.85 μM with a limit of detection (LOD) value of 33.33 fM. The satisfactory results with a minimum nonspecific adsorption effect of the aptasensor in analyzing some real samples of human blood serum, saliva and urine containing DIG not only promise DIG diagnosis in real clinical trials but also pave the way for its non-invasive measurement. The greenness of the applied strategy has been evaluated with a high score according to two international metrics, which is another achievement of this study. The synthesis of porous nanosilica from RH waste as value-added nanomaterials with outstanding features not only decreases the amount of unused RH waste piled up in nature but also, manages the synthesis costs that may be a path-breaker for more investigations.