Unraveling the Roles of Morphology and Steric Hindrance on Electrochemical Analytical Performance of <i>α</i> -Fe <sub>2</sub> O <sub>3</sub> Nanostructures-Based Nanosensors towards Chloramphenicol Antibiotic in Shrimp Samples
Nguyễn Ngọc Huyền, Ngo Xuan Dinh, Mai Quan Doan, Vu Ngoc Phan, Raja Das, Minh Tung Le, Phạm Đức Thắng, Anh‐Tuan Le
Abstract
In this work, we investigated the effect of morphology on the analytical performance of α -Fe 2 O 3 nanostructures-based electrochemical sensors toward chloramphenicol (CAP) antibiotic using three designed morphologies including α -Fe 2 O 3 nano-tube ( α -Fe 2 O 3 -T), α -Fe 2 O 3 nano-rice ( α -Fe 2 O 3 -R), and α -Fe 2 O 3 nano-plate ( α -Fe 2 O 3 -P). Among these morphologies, α -Fe 2 O 3 -T displayed an outstanding electrochemical activity owing to the unique hollow structure and large specific surface area. However, due to the small pores size, α -Fe 2 O 3 -T showed the high steric hindrance (SD) effect towards an antibiotic with complex molecular structure, as CAP, leading to a significant decrease of their CAP electrochemical sensing performance. The CAP analytical performance of α -Fe 2 O 3 -R was highest in investigated morphologies owing to a high density of exposed Fe 3+ as well as less SD effect towards CAP molecules. Under optimized conditions, α -Fe 2 O 3 -R-based CAP electrochemical sensor reached an electrochemical sensitivity of 0.92 μ A μ M −1 cm −2 with a LOD of 0.11 μ M in the detection range from 2.5–50 μ M. In addition, all these α-Fe 2 O 3 nanostructures-based electrochemical sensors had excellent stability and high anti-interference ability for CAP analysis in a complex food matrix, as shrimp sample. This study provides valuable insights into the morphology-dependent sensing properties of α -Fe 2 O 3 nanostructures towards antibiotics, which is helpful to the design of novel α-Fe 2 O 3 -based electrochemical nanosensors.