Development of pH sensitive nanofibres for milk adulteration detection is described in this work. Electrospun nanofibrous membrane of a polymer composite comprising of nylon and pH indicator dyes is synthesized to produce separate color signature for pure and adulterated milk samples. A suitable combination of pH indicator dyes is carefully chosen and their concentration in the polymer composite is optimized to successfully detect desired pH ranges. The targeted pH ranges are preferably selected to differentiate pure milk from acidic and basic milk samples. The morphological study of the electrospun nanofibres is carried out using Scanning Electron Microscopy. The efficiency of the developed nanofibrous pH sensor is experimentally evaluated using standard pH solutions. The effect of incorporation of the pH indicator dyes into the polymer composite on their halo-chromic behavior is also demonstrated in this study. This is a first of its kind study where pH sensitive nanofibres are used to detect the changes in milk acidity upon addition of adulterants. The proposed scheme can be extended towards developing a universal platform for milk adulteration detection. © 2016 IEEE.