A modified glassy carbon electrode (GCE) was prepared by incorporating carbon nanodots (CNDs) and chitosan (CS) for the determination of tryptophan (Trp). In this method, the electrochemical response of Trp was examined and the irreversible electrochemical oxidation and two electrons involved in the process of Trp were demonstrated. Because of good conductivity, large surface area, and excellent catalytic activity of CNDs, the CS and CNDs hybrid film extremely increased the electrochemical response of Trp, offering a highly sensitive electrochemical sensor for determination of Trp. The sensor showed a low detection limit of 90 nM and high sensitivity of 4 nA μM−1. The high stability and simplicity of prepared nanohybrid combined with excellent sensitivity and selectivity of the sensor may bring novel and interesting applications for different diagnoses. As a way forward, the proposed methodology is promised for fabrication of the other effective and sensitive sensors
