Aptamer and graphene-enhanced field-effect device for the sensitive and label-free detection of adenosine...

The urgent need for adenosine triphosphate (ATP) detection spans various fields, particularly in biology and medicine. Developing a simple, quick, label-free, and highly sensitive biosensor for ATP detection is crucial. In this study, we created a label-free biosensor using a field-effect device, specifically an electrolyte-insulator-semiconductor (EIS) sensor, which was functionalized with aptamer and graphene. We prepared a nanocomplex by combining graphene with bovine serum albumin (BSA) in PBS and subjecting it to ultrasonication. This Graphene/BSA mixture was then combined with 70% glutaraldehyde to form the Graphene/BSA/GA nanocomplex. The successful modification of the EIS biosensor surface with Graphene/BSA/GA and aptamer immobilization was confirmed using atomic force microscopy (AFM), which indicated successful molecule attachment through surface roughness. Electrochemical characterization revealed that the biosensor is sensitive to ATP concentrations ranging from 0.1 nM to 100 nM, with a detection limit as low as 0.32 nM. Statistical analysis demonstrated the biosensor's high sensitivity and specificity for ATP. Furthermore, the biosensor maintained stable performance for ATP detection over a period of 5 days. This sensing approach effectively detected ATP with outstanding performance, showing significant potential for advancing label-free ATP detection technologies.