DNA-based nano-sensors for recording bioelectrical signals

DNA nanotechnology enables the synthesis of intricate molecular structures with exceptional fidelity. We designed different DNA nanostructures ranging from 20 to 85 nm, with 4 to 15 indocyanine green (ICG) molecules, an FDA-approved NIR dye, per structure. Stability tests showed sustained absorbance spectra for 72 hours, with DNA-ICG remaining stable even after sonication in phosphate saline buffer. A standard MTT assay confirmed the biocompatibility of constructs, and voltage sensitivity was demonstrated in vitro, with changes in the fluorescence intensity of labeled Hela cells consistent with the accepted voltage sensitivity of ICG (∼1−2% change per 100 mV).