Photophysical property of rhodamine-cored poly(amidoamine) dendrimers: Simultaneous effect of spirolactam ring-opening and PET process on sensing trivalent chromium ion

► First synthesize two novel PAMAM simultaneously containing rhodamine and pyrazolone. ► Novel dendrimer show high selectivity and sensitivity towards Cr3+. ► Recognition Cr3+ of dendrimer G2 is dominantly due to the ring-opening mechanism. ► Sensing Cr3+ of dendrimer G3 is dependent on simultaneous mechanisms of ring-opening and PET.