Combustion of pentachlorophenol (PCP) affects guar gum product results in the production of 2,3,7,8-tetrachlorodibenzo-p-dioxin (TCDD), which affects fertility, immune system, thyroid hormone status of pregnant woman and nervous system. TCDD and PCP, the well-known potential carcinogens, can also cause environmental pollutions. In this context, an acetylcholinesterase (AChE) enzyme-based electrochemical biosensor with ZnO nanointerface was developed for the detection of TCDD and PCP in guar gum samples. In order to model the combined cyclic voltammetric responses of TCDD and PCP, a set of nine mixtures were prepared. Quantitative analysis for TCDD and PCP in a mixture has been investigated using linear regression analysis and prediction performance of the different linear models was compared. The fabricated Pt/ZnO/AChE/chitosan bioelectrode showed a linear relationship over a concentration range of 1-20 nM (R-2 = 0.99) for TCDD and PCP with a low detection limit of 0.768 and 0.534 nM, respectively. Five sets of synthetic mixtures of TCDD and PCP in guar gum samples were analysed using the proposed linear methods and yielded satisfactory results.