An optical nanosensor fabricated by carbon dots embedded in silica molecularly imprinted polymer for sensitive detection of ceftazidime antibiotic

Ceftazidime (CF) is an antibiotic, used in treatment of many serious bacterial infections. Determination of this antibiotic is essential because of its dangerous side effects. This work introduces a novel sensitive optical nanosensor based on carbon dots (CDs) synthesized using citric acid through bottom-up method, embedded in silica molecularly imprinted polymer (SMIP). This probe was made by embedding CDs as fluorophore materials, and ceftazidime as a template molecule in SMIP then washing the template molecules to provide CDs embedded in SMIP (CDs-SMIP). The synthesized materials were characterized by UV-vis (UV/Vis), fluorescence spectrophotometry, Fourier transform infrared spectrometry (FTIR), Transmission electron microscopy (TEM), and Scanning electron microscope (SEM). The obtained CD-SMIP showed strong fluorescence emission with a symmetric peak at 420 nm using excitation at 340 nm. This synthesized probe was finally applied for the detection of ceftazidime. The fluorescence intensity of CDs-SMIP quenched in presence of ceftazidime molecules. The designed fluorescence probe responded to concentration of ceftazidime over a linear range of 0.18-1.27 mu g.L-1 (0.33-2.32 nmol.L-1), also, the limit of detection (LOD) and the relative standard deviation (RSD) were 0.06 mu g. L-1 (0.11 nmol.L-1) and 3.20% (n = 5), respectively. The introduced chemical nanosensor was used to analyze ceftazidime in urine samples satisfactory.