BackgroundThe high contents of transition and heavy metal ions in environmental and biological systems have resulted in various pollutions and diseases. The technique with high sensitivity, selectivity and strong operability should be developed to monitor and analyze the microenvironment parameters. MethodsHere, a pyrene group was introduced into polyimide backbone. In order to facilitate the detection, this fluorescent polymer was made into the test paper. Significant findingsThe polymer had obvious “turn-on” fluorescent selectivity for Ag+ and Co2+ ions. The surface of test paper with nano pores exhibited smaller contact angle than that with dense layer. The water droplets on hydrophilic and porous sample could be adsorbed completely at 120 s. By comparing the fluorescence intensity of the test paper after adsorption and elution, the results showed that the samples could be reused about 5 times. This pyrene-based polyimide will open up an opportunity for developing functional fluorescence polymer in environmental monitoring.