The present invention provides, inter alia, a device comprising a colorimetric detection layer configured to undergo a color change upon interaction with a first analyte of interest. The detection layer comprises a first plurality of self-assembled fiber bundles. At least a fraction of the fiber bundles undergo a change from a first conformation to a second conformation upon interaction with the first analyte of interest, thereby undergoing a color change. The invention also provides a method for using the system to detect an analyte of interest.