Halloysite nanotubes based electrochemical sensors: A review

Among the clays, halloysite nanotubes (HNTs) are fabulous hollow tubular type of aluminosilicates due to their interesting properties such as their natural occurrence, high surface area and cytocompatibility. Different ways of functionalization for the inner and surface of HNTs have been used to control their properties for specific applications. Moreover, the modified HNTs are considered a precious carrier for nanomaterials for improving their dispersion and can be designated for electrochemical sensing application due to their high surface area. The free lumen that was in HNTs can be utilized for hosting other compounds for obtaining nanostructures with excellent synergistic properties. The main purpose of this review is for the first time conducting a survey on the reports for engineering the HNTs surface to be used as an electrochemical sensor for identifying various analytes such as hydrogen peroxide, glucose, nitrite, ascorbic acid, surface plasmon resonance, catechol amines, hydrazine, dopamine and uric acid. Moreover, the latest procedures for the modification of HNTs with specified applications have been also described.