pH and CO2 Sensing by Curcumin-Coloured Cellophane Test Strip

Curcumin-coloured cellophane test strip-fabricated without any synthetic material-is used to determine in situ the instantaneous pH changes in liquids and in the air. A low-cost, portable sensor array for possible medical and food-industrial application is developed. Next to the pH detection, curcumin-coloured test strip can be applied as CO2 monitoring sensor, too. Ongoing processes and the structural changes are followed by ultraviolet-visible (UV-VIS) spectrophotometer, attenuated total reflection-fourier transform infrared spectroscopy (ATR-FTIR) and atomic force microscope (AFM).