Coordinated molecularly imprinted-based ratiometric sensor for electrochemical sensing of hazardous ciprofloxacin based on nitrogen and sulfur co-doped porous carbon/silver nanoparticles hybrid

A highly responsive and selective coordinated molecularly imprinted polymer (MIP)-dependent ratiometric electrochemical platform for ciprofloxacin (CIPX) detection was developed. It consists of porous carbon modified with heteroatoms (N, S@C) built on pencil graphite electrode (PGE) surface. The N, S@C/PGE was then modified using silver nanoparticles (AgNPs), which were employed to boost conductivity and surface area of the electrode, as well as an internal reference signal. Molecularly imprinted film was built on AgNPS/N, S@C/PGE surface in the existence of template (CIPX) via electro-deposition of Cu (II)-coordinated pyrrole-3-carboxylic acid. The detection of CIPX is based on the measurement of ICIPX/IAgNPs ratios using differential pulse voltammetry (DPV), which were linearly proportional to CIPX concentration in the range of 0.13–650 nM with LOD (S/N = 3) of 38 pM. The as-fabricated coordinated MIP-dependent ratiometric electrochemical platform exhibited many advantages including low detection limit, long-term stability, detection reliability, and good reproducibility/selectivity. The electrochemical probe was efficiently used for the analysis of CIPX-containing specimens with recoveries % in the range of 97.6–101.6 % with RSDs % in the range of 2.6–3.2 %, proving accuracy of the platform.