Electrochemical impedance spectroscopy for monitoring caspase-3 activity

• Published in: Electrochimica acta Vol. 162; pp. 79 - 85
• Main Authors: Hung, Vinci W.S., Veloso, Anthony J., Chow, Ari M., Ganesh, Hashwin V.S., Seo, Kanghoon, Kendüzler, Erdal, Brown, Ian R., Kerman, Kagan
• Format: Journal Article
• Language: English
• Published: Elsevier Ltd 20.04.2015
• Subjects: apoptosis; caspase-3; cyclic voltammetry; electrochemical biosensor; Electrochemical impedance spectroscopy; apoptosis; electrochemical biosensor; cyclic voltammetry; Electrochemical impedance spectroscopy; caspase-3
• ISSN: 0013-4686; 1873-3859
• DOI: 10.1016/j.electacta.2014.12.115

[Display omitted] •Peptide film was immobilized on a screen-printed gold electrode.•Caspase-3 activity was detected using electrochemical impedance spectroscopy.•Biosensor performance was tested using apoptotic and healthy SH-SY5Y cell lysates.•Biosensor is a promising platform for screening novel caspase-3 inhibitors. Caspases play a key role in apoptosis and represent important therapeutic targets for treating cancer and inflammatory diseases. In this proof-of-concept study, an electrochemical impedance spectroscopy (EIS)-based biosensor was developed for the analysis of caspase-3 activity in non-diluted biological samples using screen-printed gold electrodes (SPGE) compatible with small sample volumes (i.e. 2μL). A caspase-3-specific peptide substrate was immobilized on the surface of the SPGE using N-hydroxysuccinimide (NHS)-activated lipoic acid esters. The proteolytic activity of caspase-3 was analyzed using EIS, in which the presence of the enzyme resulted in cleavage of substrate peptides. Changes in the surface-immobilized substrate peptide film were detected using the apparent charge transfer resistance (RAPP) in connection with [Fe(CN)6]3−/4− redox probe. The analytical performance of the biosensor was challenged with undiluted apoptotic human SH-SY5Y neuroblastoma cell lysates at 2-μL aliquots. Control experiments were performed with healthy SH-SY5Y cell lysates and did not display a significant decrease in RAPP values. EIS data were also confirmed using a commercially available optical kit. EIS-based biosensor demonstrated a promising potential to become a versatile tool for rapid screening of caspase-3 proteolytic activity in complex biological samples.