Evaluation of a High Sensitivity Glucose Biosensor Based on Carbon Nanotubes and Gold Nanoparticles

A glucose sensor modified by gold nanoparticles/multi-walled carbon nanotubes/Prussian blue (AuNPs/MWCNTs/PB) with high sensitivity and low limit of detection (LOD) was constructed through the characteristics of chemical crosslinking and high charge transfer. The interface between MWCNTs and PB particles accelerated the generation and transfer of induced charges, and more effectively induced the substrate glucose. The evaluation of electrochemical sensing performance was characterized by cyclic voltammetry (CV) and time-current (IT) curve. In phosphate buffer solution, the electrochemical sensing range of the sensor for glucose is 7e<inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$^{-{5}}$ </tex-math></inline-formula>–9 mM. The corresponding sensitivity and LOD are <inline-formula xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink"> <tex-math notation="LaTeX">$13.38~\mu $ </tex-math></inline-formula>A/mM/cm2 and 70 nM, respectively. The working mechanism of the sensor is analyzed and explained by theoretical simulation. In addition, we evaluated the selectivity, stability, and reproducibility of the sensor. A comprehensive comparison has been driven to the performance of glucose sensors prepared with various composite materials, including PB, MWCNTs/PB, AuNPs/PB, and AuNPs/MWCNTs/PB. To sum up, the prepared AuNPs/MWCNTs/PB glucose sensor has the advantages of simple preparation, high sensitivity, and low LOD. It has practical application prospects in glucose sensing.