Preparation of an efficient and selective voltammetric sensor based on screen printed carbon ink electrode modified with TiO2 nanoparticles for Azithromycin quantification

Abstract

The tetragonal (rutile) nanostructures of TiO2 Nanoparticles (TiO2 NPs) have gained importance due to their large active sites, electronic states influencing superior electrode performance, stability and conductivity. In this regard, Screen printed carbon ink electrode modified with TiO2 was proposed as an electrochemical sensor for the quantification of Azithromycin. TiO2 NPs was used as a modifier in order to improve the electrochemical signal of the bare carbon ink used for the screen printed carbon ink electrode (SPCIE). Some other nanostructured materials, such as Multi Walled Carbon Nanotubes (MWCNT) and Graphene Nano Platelets (GNPL), were also studied with the purpose of increasing the current signal of carbon electrode, but they did not show any expected significant effects, or they were mechanically not suitable to be printed as electrode. Azithromycin is one of the top prioritized antibiotics which are widely used by humans; lastly it is one of the most used antibiotics to treat patients with COVID-19 infection. Therefore, the determination of Azithromycin in urine samples as well as in water media is important, because of the implications antibiotics are known to have with health and natural environment. SPCIE bulk-modified with TiO2 NPs was characterized by SEM-EDS analysis. Cyclic voltammetry analysis was used to determine Azithromycin and with all optimized accompanying analytical parameters. The prepared TiO2 NPs/SPCIE electrode showed a limit of detection (LOD) of 0.93 μM with a limit of quantification (LOQ) of 3.1 µM, sensitivity of 7.36 µA µM−1 cm−2 (S/N = 3), and a linearity range of 0.05–50 μM towards determination of Azithromycin standards.