Ag Nanoplates Modified-Screen Printed Carbon Electrode to Improve Electrochemical Performances Toward a Selective H₂O₂ Detection

Abstract

Sensors based on silver nanoplates (Ag NPT) colloidal solutions, deposited onto screen printed carbon electrodes (SPCE), were fabricated and characterized. Cyclic voltammetry (CV) and linear sweep voltammetry (LSV) analyses were carried out to test the sensor performances towards hydrogen peroxide (H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ), selected as a model analyte of reactive oxygen species (ROS) involved in the regulation of metabolic/inflammatory diseases. H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> electrochemical sensing response, in terms of kinetic and sensitivity improvement, was wavelength-dependent and size-tunable. This was further confirmed by the simulation of electromagnetic field distributions based on finite difference time domain (FDTD) method. The electroanalytical behavior of the Ag NPT modified-electrodes in the presence of H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> has been studied by using the fabricated biosensor which demonstrated a sensitivity of 0.046 μA/μM for H <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> O <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> concentrations lower than 100 μM. This work proposes a surface-engineering approach to design and develop electrochemical redox probes using Ag nanoparticles (Ag NPs) with particular nanoplates morphology.