To remove toxic heavy metal ions from ground water and river, many developing countries plant trees, which is called “phytoremediation”. Phytochelatin in plants is an oligomer of glutathione, which captures heavy metal ions with a high sensitivity and keep them in vacuoles. Inspired by phytochelatin’s structure, we synthesized polymers possessing –SH and –COOH side chains. The proposed experiment aims to unravel the mechanism how bio-inspired polymers capture Cd2+ by simultaneous X-ray reflectivity (XRR) and grazing incidence X-ray fluorescence (GIXF) techniques. Using XRR we plan to detect the conformational change of polymer chains caused by Cd2+, while the number and position of Cd2+ will be calculated from the GIXF data. As our preliminary data showed that our polymer could reduce [Cd2+] to the level fulfilling the environmental standard, we believe the proposed project has a high impact to the broad scientific community.