An acyclic hexadentate oxine-derived chelating ligand, H(2)hox, was investigated as an alternative to current chelators for Ga-68. The straightforward preparation of H(2)hox, involving only one or two steps, obviates the synthetic challenges associated with many reported Ga-68 chelators; it forms a Ga3+ complex of great stability (log K = 34.4) with a remarkably high gallium scavenging ability (pGa(3+) = -log[Ga-free(3+)] = 28.3, ([Ga3+] = 1 mu M; [Lx-] = 10 mu M; pH 7.4, and 25 degrees C)). Moreover, H(2)hox coordinates Ga-68 quantitatively in 5 min at room temperature in ligand concentrations as low as 1 x 10(-7) M, achieving an unprecedented high molar activity of 11 +/- 1 mCi/nmol (407 +/- 3.7 MBq/nmol) without purification, suggesting prospective kit-based convenience. [Ga-68(hox)](+) showed no decomposition in a plasma challenge. Good in vivo stability and fast renal and hepatic clearance of the [Ga-68(hox)](+) complex were demonstrated using dynamic positron emission tomography/computed tomography imaging. The intrinsic fluorescence of [Ga(hox)](+) allowed for direct fluorescence imaging of cellular uptake and distribution, demonstrating the dual-channel detectability and intracellular stability of the metal complex.