DNA zymes as Biosensors

DNAzymes are synthetic DNA molecules that catalyze chemical reactions with the help of metal ion cofactors. Compared to protein enzymes and ribozymes, DNAzymes have advantages such as high stability, low cost, and good programmability. Over the last decade, RNA-cleaving DNAzymes have been widely utilized as biosensors for a diverse range of analytes, including metal ions, small molecules, and proteins. In particular, the sensitivity and selectivity of their catalytic activity toward metal ions are ideal for metal ion detection. In this chapter, we introduce several representative DNAzymes according to their binding targets. Various DNAzyme-based biosensors displaying fluorescent, colorimetric, or electrochemical signals are also discussed. Furthermore, signal amplification methods developed to improve the sensitivity of DNAzyme-based sensors are described.