Artificial Riboswitch: Another Engine for a Whole-Cell Sensing System to Develop Biosensors for Heavy Metal Detection

Whole-cell biosensing systems has attracted increasing research attention as a new approach for on-site heavy metal detection. However, the design and application of whole-cell biosensing systems are limited by the unsatisfactory performance of the core sensing element ─ transcription factors. This paper proposed the development of artificial riboswitches for heavy metal identification based on their high sensitivity, specificity, and ease of modification, which can be used alone or combination with transcription factors to construct more efficient whole-cell biosensors. This article summarized the reported aptamers targeting heavy metals in the last 20 years, and presented methods for screening intracellularly folding aptamers and strategies for constructing and optimizing the performance of artificial riboswitches using these aptamers. Heavy-metal-induced artificial riboswitches can be used in multiple applications, significantly enhancing the design potential of whole-cell sensing systems. Artificial riboswitches can be considered as another "engine," alongside transcription factors, to drive the development and innovation of whole-cell sensing systems.