Bioelectric calcium transport and activation in mammalian cells using field-focused DNA-carbon nanotube meshes

Electrical signaling in biology is ionic. Safe modulation needs interfaces that couple electrons to ions at soft membranes without injury. We present DNA-FOCUS, a membrane-conformal, DNA-programmed carbon-nanotube biointerface that self-assembles on living cells, weaving DNA-wrapped SWCNTs into an ultraflexible mesh. A subvolt bias is condensed into nanometer hotspots at the membrane, lowering access resistance and engaging endogenous calcium-permeable ion channels. Subvolt stimulation drives sustained Ca²⁺ influx across multiple lineages, with voltage-sensitive dye and impedance readouts showing stronger coupling. Responses occur without excess ROS or loss of viability. The focused field also enables gentle electroporation for plasmid delivery, augments mechano-electrical transduction, and modulates neuronal excitability. Transcriptional analysis and functional validation confirm NFAT activation, and in natural killer cells, it boosts perforin and IFN-γ release with higher tumor killing. This programmable, substrate-free interface supports low-voltage electro-modulation for high-throughput analytics and therapeutic augmentation.