Analysis
of biomarkers in living cells is crucial for
deciphering
the dynamics of cells as well as for precise diagnosis of diseases.
DNA biosensors employ DNA sequences as probes to offer insights into
living cells, and drive progress in disease diagnosis and drug development.
In this review, we present recent advances in DNA biosensors for detecting
biomarkers in living cells. The basic structural components of DNA
biosensors and the signal output method are presented. The strategies
of DNA biosensors crossing the cell membrane are also described, including
coincubation, nanocarriers, and nanoelectroporation techniques. Based
on biomarker categorization, we detail recent applications of DNA
biosensors for detecting small molecules, RNAs, proteins, and integrated
targets in living cells. Furthermore, the future development directions
of DNA biosensors are summarized to encourage further research in
this growing field.