Rapid detection of glutathione and spermidine by an in-situ pre-modification method based on perylene diimide derivatives

•A novel approach based on in-situ pre-modification has been developed.•This approach can enhance the interaction effectively between analytes and probes.•It enables detection of small biological molecules using perylene diimide probes.•The method features good detection performance and can be applied to real samples. For some small biomolecules with simple structures, it is difficult to achieve rapid detection because they lack strong interactions with probes. To solve this problem, we have developed an approach based on perylene diimide derivatives combining an in-situ pre-modification technique. In this strategy, the nucleophilic reaction of o-phthalaldehyde (OPA) was used to enhance the non-covalent interactions between the analyte and probe. This method was utilized for sensing glutathione (GSH) and spermidine (SPD) and had the characteristics of fast response, wide detection range, and high selectivity. Moreover, it has been validated with real samples and the detection mechanism was investigated systematically. To the best of our knowledge, this is the first attempt to apply perylene diimide derivatives to the detection of some biological small molecules by an in-situ pre-modification method.