The density functional theory (DFT) method with non-equilibrium Green's function (NEGF) method is used to study the electronic properties of the graphyne nanotube device. The graphyne nanotube is used as a base material to graft photochromic spiropyran and merocyanine molecules. The current voltage characteristics clearly give the insights on the switching properties of spiropyran and merocyanine grafted graphyne device. The findings show that spiropyran grafted graphyne device as ON state and merocyanine grafted graphyne device as an OFF state device. Moreover, upon shining light of proper wavelength, the spiropyran/merocyanine grafted graphyne nanotube device can be used as a switch. (C) 2017 Elsevier B.V. All rights reserved.