An electrochemical aptasensor based on bimetallic carbon nanocomposites AuPt@rGO for ultrasensitive detection of adenosine on portable potentiostat.

Adenosine plays a crucial role in the cardiovascular and nervous systems of living organisms. Excessive adenosine can lead to arrhythmias or heart failure, making the accurate detection of adenosine highly valuable. Given the widespread use of sensors for detecting small molecules, we propose a sensitive electrochemical aptasensor for adenosine detection in this study. The aptasensor utilized reduced graphene oxide (rGO) as the base material, and its performance was further enhanced by loading gold-platinum nanoparticles (AuPt@rGO) to improve the current response. The AuPt@rGO composite was synthesized using a simple process and was modified onto screen-printed electrodes (SPE) fabricated in the laboratory. This modification increased the effective area of the working electrode, providing more contact sites and enhancing sensitivity for adenosine detection. As a result, the sensor exhibited excellent performance in selectivity, sensitivity, and stability, with a linear response range for adenosine from 10 nM to 10 μM and a detection limit of 1.28 nM (n = 3). Furthermore, successful detection of adenosine levels in real samples was achieved using a portable potentiostat, demonstrating excellent recovery rates (95.99 %-103.4 %). These results indicate the aptasensor's significant potential for future applications in field analysis and medical diagnostics.