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Abstract: Thin coatings of molecularly imprinted, metal-complexing polymers have been grafted to activated silica beads suitable for high- performance liquid chromatography (HPLC). Propylmethacrylate- activated silica particles were coated by copolymerization with a metal-chelating monomer, Cu2+-[N-(4-vinylbenzyl)imino]diacetic acid, a metal-coordinating (imidazole) template, and ethylene glycol dimethacrylate. After extraction to remove the template and re- loading with metal, the composite materials re-bind the templates with which they were prepared and exhibit selectivities comparable to bulk-polymerized imprinted materials. The strong Cu2+-imidazole interaction, desirable for creating a high-fidelity imprint, leads to excessive retention in elution chromatography. By replacing the copper in the imprinted metal-complexing polymers with weaker-binding Zn2+, these novel ligand-exchange supports can effect partial to complete chromatographic separation of their bis-imidazole templates from other, highly similar imidazole-containing substrates. This ''bait-and-switch'' approach can significantly enhance the performance of molecularly imprinted materials. Scatchard plots of equilibrium binding data show a significant degree of heterogeneity in the imprinted binding sites of material prepared with a bis- imidazole template, but not with a mono-imidazole template. The best chromatographic separations are observed with small sample sizes, where the substrates occupy the strongest (highest-fidelity) sites