Visible Light as a Promising Signal Amplification Tool for the Efficient Electrochemical Detection of Azithromycin Antibiotic by Using Photoactive Spinel Nickel Ferrite Nanoflakes

An efficient photoactive spinel NiFe 2 O 4 nanoflakes (NFO NFs) was successfully prepared and integrated into an electrochemical sensor for the sensitive determination of Azithromycin (AZM) under visible light illumination. With the introduction of 532 nm laser illumination, NFO NFs could be easily excited and induce the charge-separation state with electrons in the conduction band and holes in the valence band. Upon illumination, the low band gap value in combination with edge-to-flat-surface/edge-to-edge conjunctions of NFO NFs could form the electron transfer pathway for transferring photogenerated electron-hole pairs to the AZM analyte-NFO electrode interface. Hence, the fabricated visible light-assisted NFO-based electrochemical sensor shows remarkable enhanced analytical performance, with calculated values of electron transfer rate constant, adsorption capacity, diffusion coefficient, and catalytic rate constant under visible light illumination of 1.29, 1.27, 2.08, and 3.40 times higher than in the dark condition, respectively. As a result, the NFO-based electrochemical sensing platform in the presence of visible light illumination possessed a high electrochemical sensitivity of 0.070 μ A μ M −1 in a wide linear dynamic range of 2.5–150 μ M and a detection limit of 1.67 μ M and also exhibited excellent anti-interference ability, repeatability, storage stability, reproducibility, and practical feasibility for AZM detection in pharmaceutical tablets.