In this study, a new methodology was used to develop a novel and sensitive electrochemical DNA biosensor for determination of furazolidone. This biosensor was fabricated from TiO2-reduced graphene oxide (rGO) modified-carbon paste electrode (CPE) decorated with ds-DNA. The oxidation signals of guanine and adenine were used as probes to study the interactions, using differential pulse voltammetry. By interaction of furazolidone with the ds-DNA, the oxidation peaks current of guanine and adenine were decreased at the modified-CPE. A linear dependence of the guanine and adenine oxidation signals with furazolidone concentration were observed in the range of 1.0-150.0 pmol L-1 with a detection limit of 0.55 and 0.43 pmol L-1 based on guanine and adenine signals, respectively. The relative standard deviation for five replicate measurements of 10.0 pmol L-1 furazolidone was 4.3%. The influence of potential interfering compounds on the selectivity was studied. This biosensor was successfully applied for determination of trace amounts of furazolidone in real samples. (C) 2015 Elsevier B.V. All rights reserved.