Solid-state nanopores have shown special high potential in a label-free molecular assay, structure identification, and target-index at the single-molecular level, even though frustrating electrical baseline noise is still one of the major factors that limit the spatial resolution and signaling reliability of solid-state nanopores, especially in small target detection. Here we develop a significant and easy-operating noise-reduction approach via mixing organic solvents with high dielectric constants into a traditional aqueous electrolyte. The strategy is generally effective for pores made of different materials, such as the most commonly used conical glass (CGN) or SiN x . While the mechanism should be multisourced, MD simulations suggest the noise reduction may partially arise from the even ionic distribution caused by the addition of higher dielectric species. Among all solvents experimentally tested, the two with the highest dielectric constants, formamide and methylformamide, exhibit the best noise reduction effect for target detection of CGN. The power spectral density at the low-frequency limit is reduced by nearly 3 orders with the addition of 20% formamide. Our work qualifies the reliability of solid-state nanopores into much subtler scales of detection, such as dsDNAs under 100 bp. As a practical example, bare CGN is innovatively employed to perform in-situ tracking of trigger-responsive DNA machine forming oligomers.

Fabricating proton exchange membranes (PEMs) with high ionic conductivity and ideal mechanical robustness through regulation of the membrane microstructures achieved by molecular‐level hybridization remains essential but challenging for the further development of high‐performance PEM fuel cells. In this work, by precisely hybridizing nano‐scaled bismuth oxide clusters into Nafion, we have fabricated the high‐performance hybrid membrane, Nafion‐Bi12‐3 %, which showed a proton conductivity of 386 mS cm−1 at 80 °C in aqueous solution with low methanol permeability, and conserved the ideal mechanical and chemical stabilities as PEMs. Moreover, molecular dynamics (MD) simulation was employed to clarify the structural properties and the assembly mechanisms of the hybrid membrane on the molecular level. The maximum current density and power density of Nafion‐Bi12‐3 % for direct methanol fuel cells reached to 432.7 mA cm−2 and 110.2 mW cm−2, respectively. This work provides new insights into the design of versatile functional polymer electrolyte membranes through polyoxometalate hybridization.