Crosslinker polycarbazole supported magnetite MOF@CNT hybrid material for synergetic and selective voltammetric determination of adenine and guanine

Abstract

Adenine and guanine, whose current concentrations are considered an important parameter for the diagnosis of various diseases, also play a key role in the storage of genetic information. Thus, accurate and sensitive determination of deoxyribonucleic acids is of great importance for clinical diagnosis. Conducting polymers and various nanoparticle-based composites have good electrical conductivity and improved sensitivity. Therefore, in this study, a novel voltammetric sensing platform based on the combination of silane-modified magnetitemetal organic framework-carbon nanotube (magnetite MOF@CNT) and electropolymerizable anthracene-carbazole compound (3) was constructed for simultaneous determination of adenine and guanine. MALDI-TOF and 1H NMR spectroscopic methods were used to elucidate the structure of compound 3. Also, the characterization of magnetite MOF@CNT nanohybrid was carried out by transmission electron microscope (TEM), scanning electron microscopy (SEM), thermogravimetric analysis (TGA), Raman, Fourier-transform infrared (FTIR), X-ray diffraction (XRD) spectroscopies. A glassy carbon electrode (GCE) was firstly modified with magnetite MOF@CNT nanohybrid then electropolymerization of compound 3 was performed on modified GCE (magnetite MOF@CNT-pC). The voltammetric sensor behaviors of adenine and guanine were investigated by cyclic voltammetry (CV) and differential pulse voltammetry (DPV) in phosphate buffer (pH 7.0). Under the optimized conditions, voltammetric responses were linearly increased in the concentration ranges from 0.5 to 35.0 mu M for simultaneous determination of adenine and guanine with the limit of detections (LODs) as 285.0 and 244.0 nM, respectively. The real sample analyses were successfully carried out for the determination of adenine and guanine in calf thymus sperm with validation by HPLC. The newly constructed magnetite MOF@CNT-pC sensor platform offers a promising candidate for simultaneous voltammetric determination of adenine/guanine and could be applied in widespread fields such as microbiology or biotechnology.