Electrochemical sandwich-type thrombin aptasensor based on silver nanowires& particles decorated electrode and the signal amplifier of Pt loaded hollow zinc ferrite

An ultrasensitive enzyme-free electrochemical sandwich-type thrombin aptasensor is proposed in this work, with the amplifier of Pt loaded hollow zinc ferrite nanospheres . Silver nanowires& particles (AgNWs&PCs) are used as the substrate materials to decorate the working electrode . Silver particles (AgPCs) are introduced for welding of AgNWs to further improve the electrical performance of the working electrode. The conductive electrode decorated with AgNWs&PCs can provide a substrate for the immobilization of thrombin aptamer 1 (Apt1). Moreover, AgNWs&PCs possess the catalytic activity for H 2 O 2 reduction, contributing to the signal amplification. The prepared Pt loaded hollow zinc ferrite nanospheres with an excellent electrocatalytic activity for H 2 O 2 reduction can also be used to immobilize aptamer 2 (Apt2). Under the optimized condition, the performance of the biosensor is evaluated by amperometry . The proposed thrombin aptasensor has a wide linear detection range from 0.05 pM to 35 nM and a low detection limit of 0.016 pM (S/N = 3), due to the synergistic effect of AgNWs&PCs electrode and the Pt loaded hollow zinc ferrite nanospheres amplifier. This aptasensor displays high sensitivity, good reproducibility and stability, providing a promising platform for the analysis of thrombin.