Rapid detection and quantification of ultralow‐concentration nanoparticles based on nanopore array blockage

Abstract Rapid and accurate detection of ultralow‐concentration nanoparticles is crucial for applications ranging from medical diagnosis to water quality monitoring, yet remains challenging for current laser‐based and light‐scattering methods. While nanoparticle‐translocation‐based nanopore sensing offers single‐particle resolution, conventional single‐nanopore resistive pulse sensing approaches suffer from low capture frequency, transient signals, and clogging issues, limiting their effectiveness at extremely low concentrations. Here, we present a novel nanopore array blockage‐based sensing strategy for the rapid detection and quantification of ultralow‐concentration nanoparticles. Using hydraulic force, nanoparticles are driven through an array of subnanoparticle‐sized pores, and optical microscopy monitors blockage progression to obtain quantitative concentration data. Our results demonstrate a linear correlation between the initial blockage rate and nanoparticle concentration, enabling the detection of fluorescent nanoparticles down to 0.5 aM (300 particles/mL) within 5 min—a three‐order‐of‐magnitude improvement in sensitivity over previous nanopore‐based methods. Additionally, our approach can leverage fluorescent nanoparticles as probes to detect unlabeled nanoparticles and contaminants at similarly low concentrations. This strategy provides a robust, efficient, and rapid platform for ultrasensitive nanoparticle detection, with promising applications in biomedical research, environmental monitoring, and industrial quality control.