Electrochemical impedance spectroscopy for monitoring caspase-3 activity

Electroanalysis of Ibuprofen and Its Interaction with Bovine Serum Albumin

The current work presents a sensitive, selective, cost-effective, and environmentally benign protocol for the detection of ibuprofen (IBP) by an electrochemical probe made of a glassy carbon electrode modified with Ag-ZnO and MWCNTs. Under optimized conditions, the designed sensing platform was found to sense IBP up to a 28 nM limit of detection. The interaction of IBP with bovine serum albumin (BSA) was investigated by differential pulse voltammetry. IBP-BSA binding parameters such as the binding constant and the stoichiometry of complexation were calculated. The results revealed that IBP and BSA form a single strong complex with a binding constant value of 8.7 × 10¹³. To the best of our knowledge, this is the first example that reports not only IBP detection but also its BSA complexation.

Tripeptide Derivative-Modified Glassy Carbon Electrode: A Novel Electrochemical Sensor for Sensitive and Selective Detection of Cd2+ Ions

A N-[(Benzyloxy)carbonyl]-l-alanyl-l-prolyl-l-leucine-N-cyclohexylcyclohexanamine (Cbz-APL) tripeptide-coated glassy carbon electrode (GCE)-based sensor was used for sensitive and selective recognition of cadmium ions in environmental water. Detailed cyclic voltammetric and electrochemical impedance spectroscopic studies were performed to investigate the charge transfer and sensing activity of the developed electrochemical sensor. Square wave anodic stripping voltammetry (SWASV) was employed to further investigate the sensitivity, selectivity, validity, and applicability of the developed sensor. A sharp electrochemical signal of oxidized Cd at -0.84 V versus Ag/AgCl provides evidence for the higher sensing ability of Cbz-APL/GCE than bare GCE at -0.79 V. Moreover, on Cbz-APL/GCE, extraordinary low detection limits of 4.34 fM and linearity range of 15 nM to 0.1 pM with coefficients of correlation higher than 0.99 for Cd2+ were achieved. Besides, the influence of inorganic and organic interferents on the targeted analyte signals was examined, and high selectivity of Cbz-APL/GCE for Cd2+ ions was observed. Lastly, the validity and applicability of the developed electrochemical sensor for the detection of Cd2+ ions were checked in real water samples, and 100% recovery was obtained.

Small Molecule Active Site Directed Tools for Studying Human Caspases

Caspases are proteases of clan CD and were described for the first time more than two decades ago. They play critical roles in the control of regulated cell death pathways including apoptosis and inflammation. Due to their involvement in the development of various diseases like cancer, neurodegenerative diseases, or autoimmune disorders, caspases have been intensively investigated as potential drug targets, both in academic and industrial laboratories. This review presents a thorough, deep, and systematic assessment of all technologies developed over the years for the investigation of caspase activity and specificity using substrates and inhibitors, as well as activity based probes, which in recent years have attracted considerable interest due to their usefulness in the investigation of biological functions of this family of enzymes.

A facile and highly sensitive impedimetric DNA biosensor with ultralow background response based on in situ reduced graphene oxide

A facile and highly sensitive impedimetric DNA biosensor with ultralow background response based on in situ reduced graphene oxide.