Update app.py

app.py

@@ -787,7 +787,7 @@ builder.add_edge("uniprot_node", "loop_node")
 builder.add_edge("listbioactives_node", "loop_node")
 builder.add_edge("getbioactives_node", "loop_node")
 builder.add_edge("pdb_node", "loop_node")
-builder.add_edge("find_node": "loop_node")
+builder.add_edge("find_node", "loop_node")
 
 builder.add_conditional_edges("loop_node", get_chemtool, {
     "uniprot_tool": "uniprot_node",