In this work, two naphthalimide-based compounds, 1a and 1b, have been designed and synthesized. Both compounds can form stable two component gels in n-propanol or n-butanol upon addition of alpha-cyclodextrin (alpha-CD) followed by sonication at room temperature. Interestingly, the 1a/alpha-CD gel is thixotropic and very sensitive to water. Addition of a small amount of water induces rapid gel collapse, allowing further development of the gel as a visual relative humidity sensor. Specificity of the sensor has been confirmed using several approaches, such as scanning electron microscopy and fluorescence, Fourier transform infrared, and H-1 NMR spectroscopy experiments. The results show that alpha-CD acts as a junction for the assembly of la or 1b through hydrogen bonding between hydroxyl and amide groups. Upon addition of water, alpha-CD interacts with the adamantane group of la via an incomplete host guest encapsulation, resulting in the dissociation of the hydrogen-bonding-assisted two-component assembly, accompanied by gel collapse.