Digital bioassay

Abstract

Digital bioassays based on single-molecule enzyme reactions represent a novel approach for quantitatively measuring biomolecules with high sensitivity using microreactor technology. Since the first reports in 2005, various types of digital bioanalytical methods have been developed due to their versatility. A prominent example is digital enzyme-linked immunosorbent assay (digital ELISA), which was primarily developed for the ultrasensitive detection of disease markers and viruses. With the advent of new microreactor technologies, the scope of detection has expanded from simple enzymes to complex systems such as membrane transporters and cell-free gene expression. Additionally, methods for evaluating enzyme heterogeneity and molecular individuality have been developed, broadening the application of these techniques beyond mere ultrasensitive detection. This review introduces the fundamental concepts of digital bioanalysis and discusses various digital bioanalytical methods. Finally, we outline future perspectives on the advancement of digital bioassay technology.