Sensors are already part of everyday life, and they are based on a mechanical and electronic pattern such as what humans see, hear and do, and they have a wide range of uses and a wide variety of types. The material that forms a sensor and its structure are very important to perform the sensing role. Electrochemical method is a kind of technology that has been promoted in modern environmental pollutant detection technology. It attracts the attention and interests of many researchers with various advantages. There are many kinds of pollution, and the persistent organic pollutants are especially harmful. Therefore, there is an urgent need to be able to quickly and accurately detect environmental pollution in the in situ method. With the development of nanotechnology, great potential has been created for the design of low-energy consumption, low-cost, high-sensitivity sensors. Due to the properties of carbon nano tube (CNT) and graphene, the combination between C-C and C-C is hexagonal in the nanostructures, which has a great reactivity and are also very stable in high temperature, high pressure, and acid conditions. Carbon Nano Tube (CNT) as nanomaterials have excellent electrical conductivity, high specific surface area and hollow structure, so it can be ideal sensor materials. Based on the excellent properties of the CNT, if the composite material is constructed, this type of material has many new properties at the same time. If such a composite material is used as an electrode, an oxidation-reduction reaction occurs between the contaminant and the electrode, which achieves the purpose of an electrochemical sensor. Synergy effect is achieved by making Metal Nano Composite based on CNT/graphene nanomaterials. These composites have both the characteristics of CNT / graphene and metal, and to make composite with these properties, uniformly plated process and surface treatment technology are required. To manufacture these composite materials, we fabricate Ag-CNT/graphene, optimized the Ag electroless plating (ELP) method for uniform aggregation on CNT/graphene, and optimize the process for the plating solution using the Raman in-situ method. The technique of analyzing the reaction process has been attracting attention from the past. It is very difficult to analyze the process in a chemical reaction because the chemical reaction causes a real-time change in molecular vibration due to a change in binding force. Therefore, there is an urgent need to be able to quickly and accurately detect a chemical reaction in in-situ method. Many electrodes can be formed by electro-less plating (ELP) technique in the sensor process, which enables low-cost and high-efficiency processing. In particular, the greatest advantage of the ELP process is that it can form layers on the nanoscale. In order to uniformly deposit Ag nanoparticles with antimicrobial activity on the surfaces of commercially available nanofilters, it is necessary to process the deposition process in real time and analyze easily. This work mainly studies the application of Multi walled CNT (MWCNT) and MWCNT composite modified electrode in the electrochemical sensor. We aimed to maximize the sensitivity of the sensor by proceeding with silver electroless plating for MWCNT and MWCNT composite. Oxidation of MWCNT showed a stronger plating effect and the pretreatmented MWCNT has a better effect.