Aptamer conjugated Si nanowire network/poly(pyrrole)-NTA structure for electrochemical sensing

Abstract

The current study describes the design, analytical characterization, and testing of aptamer sensors based on Si nanonets (Si NN) for thrombin electrochemical detection. Si nanonets are thin sheet arrays of randomly aligned Si nanowires with controlled and programmable properties that may be transported and integrated on a variety of substrates. Si nanonets were placed onto a commercial glassy carbon working electrode to create our aptasensor. Then they were functionalized by conductive pyrrole polymerization, which was followed by aptamer bioreceptor grafting. Electrochemical detection of thrombin was carried out after optimizing the electrode properties. On the one hand, cyclic voltammetry analyses demonstrated a linear association between the acquired current and the logarithm of thrombin concentration from 5 nmol L−1 to 2 µmol L−1. Impedance measurements, on the other hand, revealed a linear relationship between the charge transfer resistance as well as the impedance modulus. Thus, for the first time, Si nanonet thin sheets were used as constitutive nanoporous parts of electrodes capable of detecting thrombin at concentration limits of 5 nM, considered as a risk factor or presence of thrombosis. This demonstrates the concept of using this type of nanomaterial to detect molecules of biological interest.

Keywords

• Si nanonet
• TBA aptamer
• Thrombin
• Electrochemical impedance spectroscopy
• Cyclic voltammetry