The triazole linked o-imino phenol appended calix[4]arene conjugate (L) has been synthesized and characterized. The structure of L has been established based on single crystal XRD. The binding and recognition behavior of conjugate, L toward the transition metal ions, such as Mn2+, Fe2+, Co2+, Ni2+, Cu2+, and Zn2+, has been demonstrated using fluorescence, absorption and ESI-MS techniques. The in situ prepared complexes of these metal ions, namely, [Mn2L], [Fe 2L], [Co2L], [Ni2L], [Cu2L], and [Zn2L] have shown recognition toward Glu, Asp, His and Cys. Hence L provides a multiple sensing molecular tool where the response for the recognition of biologically active amino acids of metalloproteins is elicited by the presence of specific metal ion. © 2012 American Chemical Society.