Dr. Juewen Liu

Abstract

Functional DNA molecules involve DNA aptamers and DNAzymes, and they are popular reagents for biosensor development. This seminar first covers the metal‐specific RNA‐cleaving DNAzyme work that took place in the Liu lab over the past decade. The tested metal ions include lanthanides, thiophilic metals such as Cd2+ and Cu2+, first row transition metals such as Zn2+ and Ni2+, and Group 1A and 2A metals such as Na+ and Ca2+. The role of the scissile phosphate group is emphasized, and phosphorothioate and other modifications at the phosphate group are important to direct metal selectivity. The sodium binding aptamer discovered in some DNAzymes will be discussed. In the second part, some recent reports on non‐binding aptamers will be reviewed. Efforts in using the library‐immobilization method for the selection of new aptamers for targets such as caffeine, theophylline, uric acid and tetracycline are discussed. All these functional DNA molecules have been converted to fluorescent biosensors for their detection. Finally, new work in using artificial intelligence to search for aptamers in DNA libraries will be introduced.