The proposed method describes the use of paptode for determination of diphenylamine. The method describes chemo sensors developed for the determination of diphenylamine. The method is based on the reaction of diphenylamine with ninhydrin gives an iminium salt, on heating which formed orange color dye in acidic medium. The color system formed particular pattern on an inert support. Scanner detects the product on TLC strips and obtained pattern analyzed with program written in visual basic 6.0 (VB6). The proposed sensor is linear in concentration range 0.3- 5.1 μg/ml. All the analytical parameters and optimum reaction conditions was evaluated. The sensors are used to detect diphenylamine in real sample i.e. fruits and milk.