Wuning Zhong, Jiahui Lin, Xianwei Mo, Fei Yan, Ke He
Accurate monitoring of antitumor drug is essential for therapeutic management and safety evaluation. Herein, an electrochemiluminescence (ECL) sensor was developed for sensitive detection of antitumor drug mitoxantrone (MIT) based on surfactant-modified carbon nanotubes. Cetyltrimethylammonium bromide (CTAB)-modified carboxylated multi-walled carbon nanotube (cMWCNTs) composite (CTAB@cMWCNTs) was prepared through a simple ultrasonic-assisted assembly method and immobilized onto indium tin oxide (ITO) electrode by drop-casting. By forming a stable interfacial modification layer, enhanced ECL response was likely attributed to the inferred interfacial accumulation of luminol (emitter) and dissolved oxygen (DO, co-reactant) on the CTAB@cMWCNTs-modified ITO electrode, as suggested by cyclic voltammetry (CV) and ECL results. MIT could consume key reactive oxygen species (ROS), decreasing ECL signal and leading to signal-off ECL sensing of MIT. Enrichment of CTAB@cMWCNTs towards MIT improved detection sensitivity. The proposed sensor exhibited wide linear response toward MIT from 100 pM to 100 μM, with low limit of detection (LOD, 4.8 pM). The sensor had good selectivity and reproducibility as well as high stability. Detection of MIT in human serum was also investigated. This work provides a facile and sensitive ECL strategy for monitoring antitumor drugs and highlights the potential of surfactant-modified carbon nanomaterials in bioanalytical applications.