title: Morphology-controlled electrochemical sensing amaranth at nanomolar levels using alumina.
abstract: Different-shaped aluminas were readily prepared via hydrothermal reaction. It was found that the morphology and the electrochemical sensing properties of alumina were heavily dependent on the reaction time. When extending the reaction time from 6 h to 24 h, the obtained alumina samples changed from amorphous bumps to regular microfibers in diameter of 200 nm, as confirmed by scanning electron microscopy. Transmission electron microscopy observation revealed that longer reaction time was beneficial for the formation of porous and uniform fiber-like structures. Electrochemical tests proved that alumina microfibers were more active for the oxidation of amaranth and exhibited much higher enhancement effect, compared with alumina bumps. On the surface of alumina microfibers, the oxidation peak currents of amaranth increased remarkably. The influences of pH value, amount of alumina microfibers, and accumulation time on the signal enhancement of amaranth were discussed. As a result, a novel electrochemical method was developed for the detection of amaranth. The linear range was from 1 to 150 nM, and the detection limit was 0.75 nM after 1-min accumulation. The analytical application in drink samples was investigated, and the results consisted with the values that obtained by high-performance liquid chromatography.
authors: School of Chemistry and Chemical Engineering, Huazhong University of Science and Technology, Wuhan 430074, China.
authors: Yuanyuan
authors: Y
authors: Zhang
authors: Tian
authors: T
authors: Gan
authors: Chidan
authors: C
authors: Wan
authors: Kangbing
authors: K
authors: Wu
mesh_terms: D000537:Aluminum Oxide / Q000737:chemistry*; D000548:Amaranth Dye / Q000032:analysis*; D001628:Beverages / Q000032:analysis; D002851:Chromatography, High Pressure Liquid; D055664:Electrochemical Techniques; D004566:Electrodes; D006863:Hydrogen-Ion Concentration; D053758:Nanoparticles / Q000737:chemistry / Q000648:ultrastructure; D010084:Oxidation-Reduction; D016062:Porosity; D013499:Surface Properties
chemical_list: D000548:Amaranth Dye; D000537:Aluminum Oxide