Biorecognition and highly sensitive determination of Ribonuclease A with chemiluminescence sensor based on Fe3O4/multi-walled carbon nanotubes/SiO2-surface molecular imprinting polymer

Abstract

A chemiluminescence (CL) sensor with high sensitivity and selectivity has been developed for the determination of Ribonuclease A (RNase A). A new material Fe₃O₄/multi-walled carbon nanotubes/SiO₂ (Fe₃O₄/MWCNTs/SiO₂) was introduced into this sensor as a supporting material to prepare a surface molecular imprinting polymer (SMIP). In this work, Fe₃O₄ not only served as a backbone material in the preparation of the RNase A SMIP, but also as a separation reagent to allow the easy collection of the SMIP complex. Carbon nanotubes and SiO₂ were also used as supporting materials to prepare SMIP for their large specific surface area. The Fe₃O₄/MWCNTs/SiO₂ nanocomposite was characterized by scanning electron microscopy (SEM), X-ray diffraction (XRD) and Fourier transform infrared spectroscopy (FTIR) techniques. The adsorption ability of the Fe₃O₄/MWCNTs/SiO₂-SMIP was calculated to be 102 mg g⁻¹, which demonstrated the excellent recognition and adsorption ability of the imprinting cavities situated at or in the proximity of the surface of the Fe₃O₄/MWCNTs/SiO₂. Under optimal conditions, the linear range of the sensor extended from 1.0 × 10⁻⁹ mg mL⁻¹ to 1.0 × 10⁻⁷ mg mL⁻¹ for RNase A and the detection limit was 3.2 × 10⁻¹⁰ mg mL⁻¹ (3δ). The proposed sensor was successfully applied for the determination of RNase A in biological samples with recoveries from 93% to 105%.