A sensitive ratiometric fluorescence probe for chymotrypsin activity and inhibitor screening

• Published in: Sensors and actuators. B, Chemical Vol. 273; pp. 204 - 210
• Main Authors: Chen, Yiping, Cao, Jing, Jiang, Xiaoxue, Pan, Zhizhen, Fu, Nanyan
• Format: Journal Article
• Language: English
• Published: Lausanne Elsevier B.V 10.11.2018; Elsevier Science Ltd
• Subjects: 1,8-Naphthalimide; Biochemistry; Biomarkers; Biosensors; Charge transfer; Chymotrypsin; Fluorescence; Fluorescent indicators; Inhibitors; Intramolecular charge transfer (ICT); Peptides; Ratiometric fluorescence probe; Screening; Screening chymotrypsin inhibitor; Ratiometric fluorescence probe; Chymotrypsin; Screening chymotrypsin inhibitor; 1,8-Naphthalimide; Intramolecular charge transfer (ICT)
• ISSN: 0925-4005; 1873-3077
• DOI: 10.1016/j.snb.2018.06.021

[Display omitted] •A 1,8-naphthalimide-based ratiometric fluorescence probe of CHT has been synthesized.•A mimic peptide substrate was introduced to this probe for CHT detection.•The probe shows excellent selectivity, high sensitivity and high binding affinity.•The probe was successfully applied for the inhibitor characterization. Chymotrypsin (CHT) is involved in a series of physiological processes and disorders and it is known as a biomarker of pancreatic function. Thus, a sensitive and selective method for evaluating the relative CHT levels in different live cells is urgently needed to better understand the function of CHT. Herein, a ratiometric fluorescence probe (NI) with strong intramolecular charge transfer (ICT) has been rationally designed. The probe is constructed by incorporating a recognition group of 4-bromobutyryl into the fluorescent skeleton of 1,8-naphthalimide. The presence of CHT cleaves the 4-bromobutyryl group from naphthalimide and remarkably alters the probe's photophysical properties with a large Stokes shift, thus achieving ratiometric detection of CHT. With a detection limit of 8.4 ng/mL, NI shows high binding affinity and comparable catalytical efficiency against CHT and was successfully applied for the inhibitor characterization. The results also demonstrate that the designing strategy in the text provides a more promising application prospect for screening others CHT inhibitors.