Understanding the chemical absorption process of silver ions helps the rational design of functional materials for effective release to minimize unwanted toxicity. To this end, a histidine-containing aliphatic peptide (IH6) was designed to immobilize the silver ion (Ag+) through coordinate interaction. Using circular dichroism spectroscopy, Ag+ was found to dose dependently induce parallel beta-sheet conformation of IH6 to a saturation molar ratio of 1:2. A conformational switch of IH6 from antiparallel to parallel beta-sheet assembly upon Ag+ coordination was further revealed by Fourier transform infrared spectroscopy. The resultant Ag-IH6 hydrogel displayed substantially enhanced mechanical strength as well as controlled release of Ag+. Ag-IH6 hydrogel thus exhibited strong dose-dependent bactericidal activities that can be tuned selectively, sparing the cocultured human keratinocytes in normal. Overall, the study demonstrates an unusual silver ion-induced peptide conformational switch between beta-structure subtypes and the bilateral effects on hydrogel-based chemical control of silver ion absorption and release, thus, revealing the potential in antibacterial applications.