Molecular imprinting is an emerging technique for preparing artificial antibodies that have potential applications in affinity-based separations, biomimetic sensors and assays. The conventional imprinting methods either deliver a monolith that is mechanically ground to irregular particles - a time-consuming process with low yield, or involves complicated polymerization process by which spherical beads may be obtained, but with frequently compromised binding specificity. We have recently developed a novel molecular imprinting method that can deliver microspheres bearing imprinted binding sites, quickly, cleanly and in good yield. Imprinted uniform microspheres are synthesized by precipitation polymerization of a dilute solution of functional monomer and crosslinker in the presence of a print molecule. The method is generally applicable to a large variety of target molecules. For the first time, an enzyme probe is successfully used in a competitive herbicide assay using molecularly imprinted microspheres as the affinity adsorbents.