Biomimetic Replication of Microscopic Metal-Organic Framework Patterns Using Printed Protein Patterns

An experiment was conducted to demonstrate that zeolitic imidazolate framework-8 (ZIF-8) and lanthanide ions (Ln₂) (bdc)₃ crystalline thin films and patterns can be formed as a result of biomimetic replication directly from protein patterns on various surfaces. This rapid process was performed in aqueous conditions at room temperature with a resolution in the micrometer range. Aqueous bovine serum albumin (BSA) solutions were prepared. A clean and dry ink pad was soaked in the BSA solution and removed. For the formation of ZIF-8 thin films and patterns, separate stock solutions of zinc acetate dehydrate and 2-methylimidazole were prepared in deionized water. These two solutions were mixed and immediately transferred onto the BSA patterns. After 12 h, the formed ZIF-8 patterns were washed three times in ethanol and dried under a stream of N₂. For the formation of Ln₂) (bdc)₃ thin films and patterns, separate stock solutions of LnCl₃ hydrate and terephthalic acid disodium salt were prepared in deionized water. These two solutions were mixed and immediately transferred onto the BSA patterns. After 30 s, the formed luminescent metal?organic frameworks (MOF) patterns were washed three times in deionized water and dried under a stream of N₂.