RESUMEN
In this study, two metal oxide nanoparticles NiO and MnO2 were synthesized from green sources Mentha spicata (M. spicata) extract and Malus domestica (M. domestica) peel extract, respectively. The optical and physical properties of the synthesized nanoparticles were characterized using spectroscopic and microscopic techniques. Simple, precise, and new spectrophotometric probes were suggested for the determination of three cephalosporin antibiotics, including levofloxacin (LVX), cephalexin (CPX), and cefotaxime sodium (CTX) in their pure form and commercial products. The spectrophotometric detection of the selected drugs is based on the catalytic enhancement of NiO and MnO2 nanoparticles (NPs) due to their unique optical properties. Linear relationships with main correlation coefficients 0.999 were obtained at 0.1-20, 1.0-80, and 0.001-100 µg mL-1 for the three drugs in the presence of NiONPs, whereas 0.01-60, 0.1-160, and 0.01-80 µg mL-1 were obtained in the presence of MnO2NPs at absorption wavelengths 290, 262, and 235 nm for LVX, CPX and CTX, respectively. The analytical methods were validated and successfully used for determination of the instigated drugs in their bulk and commercial dosage forms.
RESUMEN
The rapid detection of lung cancer in early stages using the antigen cytokeratin-19 fragment (CYFRA 21-1) as a tumor marker in human serum plays an important role in the survival of patients and taking a fast surgical reaction. This study aimed to employ the green synthesized carbon quantum dots conjugated zinc oxide nanocomposite as a highly sensitive fluorescence immunosensing solution for fast determination of CYFRA 21-1 antigen in human serum. The suggested method was conducted by applying a hydrothermal method to prepare carbon quantum dots using Citrus lemon pericarp. The formed carbon quantum dots were used in the reduction and stabilization of zinc acetate to synthesize carbon quantum dots-zinc oxide nanocomposite. To form a sandwich capping antibody-antigen-antibody immunosensing system, a CYFRA 21-1 antigen was trapped by immobilizing a non-conjugated monoclonal antibody BM 19.21 on the surface of carbon quantum dots-zinc oxide nanocomposite and another monoclonal antibody KS 19.1, which was coated on the microtiter well surface. This system has a tunable fluorescence feature recorded at excitation and emission of λex = 470 and λem = 520 nm, respectively. The suggested nanocomposite fluorescence immunosensing system displayed a linear relationship of 0.01-100 ng mL-1 with a limit of detection of 0.008 ng mL-1. The suggested immunosensing system based on carbon quantum dots-zinc oxide nanocomposite provides a promising approach for rapid diagnoses of lung cancer by detecting CYFRA 21-1 in human serum.
