Application of Fe3O4 nanoparticles functionalized carbon nanotubes for electrochemical sensing of DNA hybridization

In this paper, a novel sensing platform based on Fe3O4 nanoparticles functionalized carbon nanotubes (CNTs) was developed for highly sensitive label-free detection of BCR/ABL fusion gene from chronic myelogenous leukemia. The morphology and electrochemical performance of the Fe3O4/CNTs nanocomposite membrane were systematically investigated. Combining the biocompatibility of Fe3O4 nanoparticles with the excellent electron transfer ability and large surface area of CNTs could improve the density of DNA probe attachment and the sensitivity of DNA detection. Remarkable change has been observed in the impedance spectra before and after hybridization of the probe ssDNA with the target DNA. Under optimal conditions, the dynamic range for detecting the sequence-specific DNA of the BCR/ABL fusion gene was from 1.0 x 10(-15) to 1.0 x 10(-9) mol L-1, and the detection limit was 2.1 x 10(-16) mol L-1. In addition, the DNA electrochemical biosensor was highly selective to discriminate single-base and double-base mismatched sequences.