Considering the significance of atomic-level modulations into nanoscale architectures have become unique, attractive ideas in the field of sensors and decontamination of organic pollutants from the noxious environment. In this work, a novel bifunctional copper ion-modulated nickel telluride nanoflakes are achieved by a hydrothermal method that is applied as a bifunctional catalyst for sensing the level of L-dopa and removing the organic dye pollutant from the environment. The facile processable Cu-NiTe2 nanoflakes are reported for the first time to enable the semiconductor fabrication as a bifunctional catalyst through a low-cost approach. The cation modulation of copper atoms effectively alters the NiTe2 crystal lattice and yields superior physicochemical nature of bifunctional Cu doped NiTe2 crystal structure. The Cu doped NiTe2 effectively shows the efficient separation of electron-hole pairs and enhanced light-harvesting performance, thus exhibits better photocatalytic activity for the crystal violet dye degradation in visible light radiation within 150 min, and nearly 98% degradation occurs for 5%Cu/NiTe2. The enhanced electrocatalytic sensing of L-dopa is attained for 5% Cu/NiTe2 and the concentration range from 0.9 × 10− 6 to 9.9 × 10− 6 M and the value of the limit of detection is 0.308 µMµA− 1. The 5% Cu/NiTe2 catalyst showed good electrochemical sensing ability towards L-dopa.