The document summarizes research on developing novel transcriptional regulators (TFs) that can sense small molecules by fusing DNA-binding domains (DBDs) to ligand-binding domains (LBDs). The researchers generated a library of potential TFs by combining 15 DBDs with 15 LBDs using a ligase cycling reaction. They screened the library using flow cytometry to enrich for TFs that repressed GFP expression in the absence of inducer benzoate but allowed expression in its presence. Two top-performing TFs were characterized further and shown to repress promoter activity until benzoate was added, demonstrating their potential as biosensors.