Conductive polymer hydrogel-coated nanopipette sensor with tunable size

Nanopipette-based sensors are one of the most effective tools for detecting nanoparticles, bioparticles, and biomolecules. Quantitative analysis nanoparticles with different shapes electrical charges is achieved through measurement blockage currents that occur when particles pass nanopore. However, typical nanopipette fabricated using a conventional needle-pulling method have pore-diameter limitation around 100 nm. Herein, we report novel conductive hydrogel-composited sensor tunable inner-pore diameter. This made by electrodepositing poly(3,4-ethylenedioxythiophene) polystyrene sulfonate onto surface prefabricated sacrificial copper layer. Because presence ions, polymer can stably adhere to tip form nanopore; nanopore, more distinct blocking events observed. The size nanopore be changed simply adjusting electrodeposition time. In this way, suitable nanopores obtained highly sensitive screening series diameters order tens nanometers.