MNAzyme-Assisted Nucleic Acid Lateral Flow Assay for Cost-Effective, On-Site Mercury Detection.

Mercury ions (Hg) are toxic heavy metals present in the environment that pose significant health risks. An advanced detection system could allow for a prompt response and alleviate serious damage to humans. In this study, we developed a cost-effective, on-site detection method for Hg using a multicomponent nucleic acid enzyme (MNAzyme)-assisted nucleic acid lateral flow assay (NALFA). The MNAzyme, which was engineered to contain thymine-thymine mismatches, is responsive only to the presence of Hg and exerts efficient cleavage activity on substrates that can be captured by the NALFA strip, and thus the proposed system enables the visual detection of Hg in the NALFA strip. Our assay demonstrated sufficient detection sensitivity and specificity to meet the WHO standards, offering a good practical alternative for rapid environmental and public health monitoring.