Noiseless nanosensor for non-invasive recording of biopotentials

We have studied the intrinsic noise of nanosensors. Four technologies for incorporation of silver nanoparticles into porous aluminum–silicon oxide ceramic plates were tested. Before incorporation, the pore volume was 11 %, the pore size was 1 – 5 µm, and the surface area of the pores was 0.182 m². Group (1) included nanoparticles of 167 – 952 nm in size, nanosilver mass was 1.5 – 35.0 %; Group (2) included nanoparticles of 70 – 400 nm in size, nanosilver mass was 0.4 – 68 %; Group (3) included nanoparticles of 49 – 324 nm in size, nanosilver mass was 0.6 – 72.0 %; Group (4) included nanoparticles of 57 – 142 nm in size, nanosilver mass was 12.92 – 31.29 %. After silver nanoparticle incorporation, the pore volume attained 9 %, 8 %, 7 %, and 10 %, respectively. The self-noise energy of nanosensors made of Group (4) plates was virtually zero. Noiseless nanosensors enabled recording of cardiac micropotentials from a level of 50 nV.