Functional nucleic acid-based fluorescence polarization/anisotropy biosensors for detection of biomarkers.

The sensitive and selective detection of biomarkers plays a crucial role in disease diagnostics, drug discovery, and early screening of cancers. The achievement of this goal highly depends on the continuous development of biosensing technologies. Among them, fluorescence anisotropy/polarization (FA/FP) analysis receives increasing interest due to the advantage of simple operation, fast response, and no background interference. In recent decades, great progress has been achieved in FA/FP sensors thanks to the development of functional nucleic acids (FNAs) including aptamers and nucleic acid enzymes. This review focuses on FNA-based FA/FP sensors for the quantitative detection of biomarkers, such as nucleic acid, small molecules, and proteins. The design strategies, recognition elements, and practical applications are fully highlighted. The article also discusses the challenges of applying FNA-based FA/FP sensors in the next generation and the potential solutions along with future prospects. Graphical abstract.