A potential binding assay based on conformational-change-induced micromechanical motion is described. Calmodulin was used to modify a microcantilever (MCL) by a self-assembled layer-by-layer approach. The results showed that the modified MCL bent when the proteins changed their conformation upon binding with Ca2+. The cantilever deflection amplitudes were different under different ionic strengths, indicating different degrees of conformational change of the proteins in these conditions. On the contrary, cantilevers modified by proteins, such as hemoglobin and myoglobin, that do not change conformations upon binding with analytes do not cause the cantilever deflection. These results suggest that the conformational changes of proteins may be used to develop cantilever biosensors, and the MCL system has potential for use in label-free, protein-analyte screening applications.
Detection of hydrogen peroxide is of industry interest and of biological importance. Here we report a new approach to hydrogen peroxide measurement using multilayer modified microcantilevers. Through a layer-by-layer nanoassembly technique, horseradish peroxidase was intercalated into a nanoscale multilayer assembly on one surface of microcantilevers.These enzyme-functionalized microcantilevers deflected in response to hydrogen peroxide concentrations in the nanomolar level. The magnitudes of bending were proportional to the concentrations of hydrogen peroxide. Furthermore, our study also showed that microcantilever technique may be used as a novel, more sensitive tool for the study of the conformational or structural changes of enzymes or proteins on surfaces.
scite is a Brooklyn-based organization that helps researchers better discover and understand research articles through Smart Citations–citations that display the context of the citation and describe whether the article provides supporting or contrasting evidence. scite is used by students and researchers from around the world and is funded in part by the National Science Foundation and the National Institute on Drug Abuse of the National Institutes of Health.