Electrochemiluminescence Sensor Based on N-Doped Carbon Quantum Dots for Determination of Ceftazidime in Real Samples
Hosein Afshary, Mandana Amiri, Abolfazl Bezaatpour, Michael Wark
Abstract
In this work, we report an electrochemiluminescence (ECL) sensor based on nitrogen doped carbon quantum dots (N-CQDs), which has been synthesized by a solvothermal method. The N-CQDs were characterized using various techniques such as high-resolution transmission electron microscopy (HR-TEM), field emission scanning electron microscopy (FE-SEM), UV–vis absorption and photoluminescence spectroscopy, FT-IR spectroscopy, X-ray photoelectron spectroscopy (XPS) and X-ray diffraction (XRD). The potential sweep range (−0.5 to −2.2 V) shows a stable and strong ECL signal. Interestingly, the ECL intensity only decreased by less than 20% after storing at 4 °C for 10 months. The applicability of the N-CQD sensor in electroanalytical chemistry was identified by the linear ECL on–off response for ceftazidime in a concentration range from 1 × 10 −7 to 5 × 10 −4 mol l –1 and a detection limit of 2.3 × 10 −8 mol l –1 . The results suggest that the proposed ECL sensor is robustly applicable for analysis of ceftazidime in real samples such as human serum, bovine milk and commercial milk powder.