By utilizing laboratory-guided evolution, we have converted the fluorescent proton-pumping rhodopsin GR from Gloeobacter violaceus into GR1, a red-shifted, turn-on fluorescent sensor for chloride.
A new calixpyridinium-based light-responsive host–guest recognition motif was found in this work. This host–guest recognition motif was further discovered to be applied as a selective turn-on fluorescent sensor for lysine.
The fluorescence sensing properties of a naphthalene-based acetohydrazide (3) were investigated. A highly selective “turn-on” response was obtained towards Al3+ ions, and this was used for real sample analysis and development of paper test strips.