We designed and synthesized two new types of crosslinked helical peptides that interact with the target DNA. One of them was crosslinked with a conventional isophthalic acid-based agent and was modified with alpha-lipoic acid at the N-terminus. The other peptide was crosslinked with a novel isophthalic acid-based agent containing alpha-lipoic acid at its own 5-position. Quartz crystal microbalance analyses showed that both the helical peptides strongly bound to their target DNAs on the Au surface.