P 2000 laser based pipette puller

Glass nanopipettes were fabricated from quartz capillaries (World Precision Instruments) as protocol reported by our group previously^{25 (link),26 (link),46 (link)}. In brief, capillaries (internal diameter: 0.5 mm, external diameter: 1.0 mm, length: 7.5 cm) were plasma cleaned for 10 min to remove any contaminated residues and pulled using a P-2000 laser-based pipette puller (Sutter Instrument, USA) to achieve two nanopipettes under the set of a two-line pulling protocol: (1) HEAT: 775; FIL: 4; VEL: 30; DEL: 170; PUL: 80, (2) HEAT: 825; FIL: 3; VEL: 20; DEL: 145; PUL: 180. This protocol generates pores with a diameter of (21 ± 2) nm. This protocol is puller specific  and should be optimised accordingly.

Quartz capillaries (Intracel Ltd, UK) length 75 mm with 0.5 mm filament was placed inside a plasma cleaner to remove any organic contaminants. Nanopipettes were fabricated using a P-2000 laser-based pipette puller (Sutter Instrument, USA). The pipettes used in Figs. 2, 3 and 5 were fabricated from protocol reported^{12 (link), 13 (link)}. The pipettes used in Fig. 4 were fabricated using a two-line programme: (1) HEAT: 775; FIL: 4; VEL: 30; DEL: 170; PUL: 80, (2) HEAT: 825; FIL: 3; VEL: 20; DEL: 165; PUL: 180 to yield a conductance of 5.8 ± 0.8 nS (mean ± 1 standard deviation). It should be noted that the above parameters are instrument specific and might have slight variations due to local temperature and humidity.