Design principles of chemiluminescence (CL) chemodosimeter for self-signaling detection: luminol protective approach

Chemiluminescence (CL) sensors can provide convenience and high sensitivity because they do not require an external excitation light source to produce a fluorescence signal. However, most CL based detection systems do not have a built-in self-signaling process, leading to inefficient and complex protocols due to the required multistep cascade reactions. Here, we develop a CL based sensory system with a built-in self-signaling feature by adapting the chemodosimeter concept. We found that a masking group incorporated to luminol efficiently suppresses the CL of luminol and that selective removal of the masking group by a target analyte can turn on the CL process, generating a sensitive fluorescence turn-on signal. Through systematic studies on newly devised TBS-luminol and TIPS-luminol, we optimized the molecular design parameters to achieve a highly sensitive and selective CL chemodosimeter. The optimized conditions rendered highly sensitive (Limit of Detection (LOD) = 18 nM) and selective fluoride sensing in aqueous environments. We anticipate that our new sensor system offers an efficient way to achieve highly sensitive, selective, and convenient CL turn-on detection of various important analytes.