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A bifunctional ligand that is capable of forming Re and ^99mTc complexes as complementary fluorescent and radioactive probes was developed. The tridentate bis(quinoline) amine ligand, which is referred to as the SAACQ system, was prepared in a single step from Fmoc protected lysine in high yield. Reaction of the SAACQ ligand with [Re(CO)₃Br₃]^2- resulted in the formation of the SAACQ−(Re(CO)₃)⁺complex which exhibits favorable fluorescence properties including a long lifetime and a large Stoke's shift. Because the SAACQ ligand is derived from an amino acid, it can readily be linked to or incorporated within peptides as a means of targeting the probe to specific receptors. To demonstrate this feature, the SAACQ ligand and the SAACQ−Re complex were incorporated into fMLFG, a peptide that binds to the formyl peptide receptor (FPR). Uptake of the fMLF[(SAACQ−Re(CO)₃)⁺]G conjugate into human …