Picric acid is a kind of dangerous and toxic nitroaromatic explosive chemicals and causes great concern in safety, health and environment issues. However, the visual and selective sensing of picric acid in pure water is still a challenge in recent years. In this work, two novel isomeric sugar-based derivatives denoted as NGs (NG1 and NG2) with different terminal groups (pyridyl segments) have been designed and synthesized. We demonstrate the preparation of picric acid assisted supramolecular hydrogels driven by hydrogen bonding interaction, which endows the visual and direct recognition for picric acid via fast and selective gelation approach without expensive equipment. The binding mechanism of NGs with PA both in solutions and gels and the isomeric effect on the gelation properties are studied in detail by several techniques. At last, NG2 based test strips are also developed to detect tiny amount of PA in water in a contact mode.