Polymeraseicking enzyme synergetic isothermal quadratic DNA machine and its application for one-step amplified biosensing of lead (II) ions at femtomole level and DNA methyltransferase

摘要

Researchers in China have developed an ultrasensitive DNA-based biosensing system with many possible medical and environmental applications. The team led by Yongxi Zhao of Xi'an Jiaotong University and Chunhai Fan of the Chinese Academy of Sciences proved the versatility of their one-step ‘DNA machine’ using lead ions and a DNA methyltransferase enzyme as example analytes. The system can be tailored so that a chosen analyte activates a rapid DNA amplification cascade that changes a quenched fluorescent group into an actively fluorescent state. The intensity of the fluorescence reveals the concentration of the analyte. The procedure is simpler, more sensitive and quicker than existing alternatives, and crucially does not require the cycled temperature changes generally needed for DNA amplification. The researchers now plan to adapt the process to detect many other chemicals, including biomarkers of cancer.