Phytic acid modified soy protein isolate/chitosan film: A multi-functional and degradable bio-based composite material for fire alarm sensor

•The bio-based film sensor showed quick responses to flame and temperature.•The film sensor exhibited good sensitive responses at 68–194 °C.•The film possessed flame retardancy, water stability, and good degradability.•The film is non-toxic and eco-friendly in terms of raw materials, film manufacturing.