Here, we fabricate an ultrasensitive acetaminophen (AC) sensor by using networked nanocarbons (NWNC) derived from hierarchical porous polypyrrole (PPy) hydrogel precursor. Benefiting from the interconnected porous framework and high electron conductivity of this N, P co-doped NWNC, the as-constructed sensor shows record-high sensitivity (102.05 μA μM −1 cm −2 ) and ultra-low detection limit (3.0 nM), which represents a performance progress in AC sensing. Furthermore, the sensor displays excellent selectivity, reproducibility and stability, exhibiting a great perspective in ultrasensitive monitoring of AC in clinical application.

A "green nano" strategy was extended to prepare monodisperse polypyrrole (PPy) nanospheres with tunable sizes via simply adjusting pyrrole monomer's concentration. And a linear model was obtained and used to predict the diameter of PPy nanosphere. Nitrogen-doped carbon nanospheres (NCSs) with well-controlled diameters were further synthesized through direct carbonzilation of harvested PPy nanospheres, which demonstrated a facile route for the preparation of highly dispersible NCSs with controlled sizes. Then the potential electrochemical response of as-fabricated NCSs toward food additive-Sunset yellow (SY) was explored. NCSs with medium size (M-NCSs) showed the best electrochemical performance and an ultra-high sensitivity of 679.16 A M −1 cm −2 and lower detection limit of 0.95 nM were gained. This study therefore provides a facile route to high quality, uniform, and size-controlled PPy nanospheres and NCSs, which are promising to be applied to electrochemical and other fields.

Three-dimensional (3D) aerogels have attracted more and more attention in oil–water separation, due to their advantages of low density, high porosity, and large specific surface area.