Nano-p-n junction heterostructure TiO2 nanobelts for the electrochemical detection of anticancer drug and biointeractions with cancer cells.

Abstract

Nano-p-n junction heterostructures based on TiO2 nanobelts with enhanced (001) facets were produced by assembling p-type semiconductor NiO nanoparticles on n-type surface-coarsened TiO2 nanobelt surfaces. The heterostructures were then used as the sensing electrode for the electrochemical detection of anticancer drugs O6-benzylguanine (O6BG) and lung cancer cells. O6BG exhibited an irreversible diffusion-controlled electrochemical process with an oxidation peak clearly identified at +0.78 V. For lung cancer cells one oxidation peak was found at +1.1 V and two reduction peaks at +0.30, and +0.90 V. These voltammetric features disappeared when O6BG was added to the lung cancer cells, which was ascribed to the structural changes of the cell membranes caused by the anticancer drug. These results suggested that nano-p-n junction heterostructures based on TiO2 nanobelts might serve as promising candidates for biosensing applications of anticancer drugs and tumor cells that will be of significance in diagnostic medicine, cancer diagnosis and molecular biology research.