Dimethoate (DMT) is an organophosphate pesticide (OP), which is widely used against insects and mites and their control in agriculture. As other OPs, DMT is also an inhibitor of acetylcholinesterase, which is responsible for the disabling of cholinesterase required for the functioning of the central nervous system. This pesticide can invade living cells of the human body through contact or ingestion. We report an electrochemical sensor based on a layer by layer deposition of PDAC/GO on silver electrodes. The sensor fabrication, physical characterization i.e. Raman spectroscopy and scanning electron microscopy of PDAC/GO based films, and its electrochemical characterization are discussed. The detection of DMT by analyzing electrochemical measurements including cyclic voltammetry and impedance spectroscopy shows that functionalization using layer by layer deposition improves electrochemical response and presents a basis for detection of DMT. The highest response is observed in the case of only one PDAC/GO layer which is attributed to the properly balanced interaction between DMT and PDAC/GO layer, and the increase of electrical resistivity of the PDAC/GO layer with its thickness.