The properties of graphene nanoribbons are highly dependent on structural variables such as width, length, edge structure, and heteroatom doping. Therefore, atomic precision over all these variables is necessary for establishing their fundamental properties and exploring their potential applications. An iterative approach is presented that assembles a small and carefully designed molecular building block into monodisperse N‐doped graphene nanoribbons with different lengths. To showcase this approach, the synthesis and characterisation of a series of nanoribbons constituted of 10, 20 and 30 conjugated linearly‐fused rings (2.9, 5.3, and 7.7 nm in length, respectively) is presented.

Twisted two‐dimensional aromatic frameworks have been prepared by overcrowding the nodes with bulky and rigid substituents. The highly distorted aromatic framework with alternating out‐of‐plane substituents results in diminished interlayer interactions that favor the exfoliation and dispersion of individual layers in organic media.

A simple and expedite electrochemical methodology was developed for the determination of ciprofloxacin, based on a glassy carbon (GC) electrode modified by a combination of multi-walled carbon nanotubes (MWCNT) with β–cyclodextrin (β–CD) incorporated in a polyaniline film. The combined use of β–CD and MWCNT in the electrochemical sensor leads to a significant signal improvement. The β–CD/MWCNT modified GC electrode exhibited efficient electrocatalytic behavior in the oxidation of ciprofloxacin with relatively high sensitivity, stability and lifetime. Molecular modeling studies showed that ciprofloxacin binds preferably to β–CD rather than to CNT edges, leading to an improved sensitivity of the sensor. Under optimized conditions, a linear calibration curve was obtained for ciprofloxacin in the concentration range 10–80 µM with a detection limit of 50 nM. The analytical performance of this sensor was evaluated for the detection of ciprofloxacin in a wastewater treatment plant effluent.