Indoor formaldehyde (FA, HCHO) contamination is currently one of the most significant environmental concerns in daily life, making it vital to detect FA efficiently. Colorimetric FA detection is a fast, real-time method with results visible to the naked eye. However, most colorimetric FA sensors on the market have complex and expensive base materials. In this work, different sections were prepared as colorimetric sensor substrates according to the anisotropy of natural poplar trees. The response characteristics of FA on the different sections were compared, showing that the longitudinal sectio...
