Due to the necessity of measuring glucose as the main fuel of the body in biological samples [1], it is necessary to prepare the sample containing the test analyte, concentrate the desired test species and extract it from other containing of sample [2]. Various extraction methods have been developed to prepare samples before separation and measurement. In this regard, three-phase liquid microextraction methods with hollow fiber using a small amount of organic solvent provide a high contact surface [3]. Also, electrochemical sensors have received more attention than other analytical methods. Among their advantages, we can mention sensitivity, accuracy and speed in measurement [4]. Here, the glucose was separated and preconcentration by using a simple extraction cell including porous fiber three-phase microextraction method and it measured with differential pulse voltammetry (DPV) method at surface of poly (1- naphthylamine)/ Ni (Ⅱ)/ pencil graphite electrode. Therefore, combining of porous fiber three- phase microextraction with DPV showed linear dynamic range ( 4.0×10-5 – 8.0×10-3 µM and 4.0×10-2 – 8.0 µM) with detection limit (LOD) 1.41×10-5 µM in optimal conditions. The electrochemical sensor exhibits excellent electrochemical performance, low LOD, wide LDR, high stability for non- invasive glucose measurement. In addition, the proposed method has shown a good recovery percentage (92-111) with optimal accuracy and precision for non- invasive measurement of glucose in different blood plasma samples of healthy and diabetic people.
