An electrochemical aptasensor based on multi-walled carbon nanotubes loaded with PtCu nanoparticles as signal label for ultrasensitive detection of adenosine

Adenosine, as an endogenous nucleoside modulator , plays an important role in heart rate regulation, neurotransmission , and control of the respiratory system and thus it is significantly important to realize its sensitive detection . Herein, a highly sensitive electrochemical aptasensor for adenosine detection was proposed by using multi-walled carbon nanotubes (MWCNTs) as support matrix loading PtCu nanoparticles (PtCu-MWCNTs) to amplify signal. On one hand, disposable screen-printing gold electrodes (SPGEs) were used as superb sensing base to ensure the stable connection of aptamers 1 (ssDNA1). On the other hand, the PtCu-MWCNTs complex was synthesized through a one-pot method, which not only can precisely control the proportion of metal mass in the product but also exhibited superior electrocatalytic activity towards H 2 O 2 . The recognition reactions were achieved by stepwise incubation of ssDNA1, ssDNA2-PtCu-MWCNTs (denoted as ssDNA2-label), and adenosine on the SPGEs. As a result, the constructed electrochemical aptasensor exhibited a wide linear range from 10 nM to 1.0 μM with a low detection limit of 1.0 nM (S/N = 3) for adenosine detection. The aptasensor also successfully realized the adenosine detection in human serum samples, which means that the proposed aptasensor holds a potential application in point-of-care detection.