Handmade oxygen and carbon dioxide sensors for monitoring the photosynthesis process as instruction material for science education

The handmade oxygen sensors could monitor the oxygen consumption process in a container where a candle or a disposable pecker warmer was placed. The g eneration and consumption process of oxygen and carbon dioxide in the photo synthesis using spinach leaves was also monitored in real-time. The photosy nthesis apparatus was easily constructed by using a commercially available fluorescent lamp, spinach leaves, and a PET bottle or a desiccator containe r. A commercially available polyethylene film that is permeable to oxygen a nd an electrolyte were examined to assemble an electrochemical sensor. The change of carbon dioxide concentration could be measured easily using an el ectrochemical carbon dioxide sensor. From the light-dark reaction, the carb on dioxide concentration was observed to decrease with increase in the oxyg en concentration. Useful instruction tools for chemistry and biology studen ts could be proposed. (C) 2001 Elsevier Science B.V. All rights reserved.