Paper-based sensing of pancreatic-cancer biomarker α-chymotrypsin through turn-on lanthanide-luminescence†

We report the facile detection of a pancreatic cancer biomarker α-chymotrypsin (Chy) by turn-on, time-gated lanthanide luminescence for the first time. To the best of our knowledge, the non-peptide probe we designed is the simplest one currently available. The probe undergoes Chy-induced release of the sensitizing antenna (2,3-dihydroxynaphthalene), leading to enhanced lanthanide luminescence. The detection protocol was further modified to develop a paper-based sensor and was used to detect Chy in commercial tablets, and to rapidly screen Chy-inhibitors.