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 H2O2 reduction, contributing to the signal amplification. The prepared Pt loaded hollow zinc ferrite nanospheres with an excellent electrocatalytic activity for H2O2 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.

Automated summary

A novel electrochemical thrombin sensor was developed in this study, utilizing silver nanowires & particles and Pt-loaded zinc ferrite nanospheres as amplifiers for ultra-sensitivity and promising platform for thrombin analysis.