A G-quadruplex-based method to detect ClO− in the rostral ventrolateral medulla of stress-induced hypertension by self-complementary DNA probe

A G-quadruplex-based fluorescent biosensor is introduced that employs a self-complementary DNA probe for detection of hypochlorite ions (ClO⁻) in the rostral ventrolateral medulla (RVLM) of rats afflicted with stress-induced hypertension (SIH). The biosensor capitalizes on the interaction between Thioflavin T (ThT) and guanine-rich DNA sequences, exhibiting exceptional sensitivity, specificity, and swift detection capabilities for ClO⁻. Through optimization of the detection parameters, we achieved a minimal detection threshold of 0.0486 μM and a rapid reaction time of 5 min. The biosensor’s high selectivity for ClO⁻ was confirmed by its lack of response to other reactive oxygen species (ROS). When applied to SIH rat models, the biosensor revealed markedly elevated ClO⁻ levels in the RVLM of SIH rats versus control rats, implicating ClO⁻ in the disease’s pathophysiology. This label-free, G-quadruplex-based biosensor represents a significant advancement in the detection of ClO⁻, offering a highly sensitive and specific tool for monitoring reactive oxygen species in biological systems. This study not only deepens our comprehension of SIH but also offers a potent diagnostic and monitoring tool for ROS-related diseases, with implications for therapeutic intervention and disease management.

Graphical Abstract