Fig. 2
From: Microfluidic DNA-based potassium nanosensors for improved dialysis treatment
The DNA nanosensors are composed of three hybridized oligonucleotides: a fluorophore (FAM), a quencher (DABCYL), and a scaffold oligonucleotide. In the presence of buffer, the DNA nanosensor complex fluoresces. When potassium is present, the DNA nanosensor complex forms a more compact G-quadruplex structure and brings the fluorophore and quencher closer together, causing the fluorescence signal to decrease