Colorimetric chemosensors can easily detect and prevent the primary danger or change of the surrounding environmental pollutions and sources of infection in the various fields. Pyran based colorant having the function of colorimetric chemosensor was synthesized. Synthesized colorant was characterized by $^1H$ NMR, GC-Mass, EA and UV-vis spectroscopy and then mixed with polyacrylonitrile for electrospinning. Electrospun fibers containing pyran based colorant were used as pH detecting chemosensor and were analyzed by SEM, XPS, and spectrophotometer.