A novel in situ molecularly imprinted sol-gel nanomembrane using nylon 6 as backbone was prepared by the electrospinning technique and coupled on-line with high-performance liquid chromatography. The prepared electrospun membrane exhibited extensive selectivity toward acesulfame in the presence of some selected sweeteners in a beverage sample, while the porosity and mechanical stability remained. The prepared electrospun membrane could be applied for 35 consequence extractions without a significant change in extraction recovery, swelling, and flooding. To achieve the best condition and efficiency for on-line extraction, the effect of influential parameters was investigated. The limit of detection (signal/noise = 3:1) and limit of quantification (signal/noise = 10:1) were 0.6 and 2.0 ng/mL for acesulfame in the beverage samples, respectively. The linearity for the acesulfame was in the range of 2.0-250 ng/mL in beverage samples. The coefficients of determination values were >= 0.997 for all runs. The extraction recoveries of acesulfame in the beverage samples were between 80 and 85%.