Batch-Injection Amperometric Determination of Glucose Using a NiFe2O4/Carbon Nanotube Composite Enzymeless Sensor

• Published in: Chemosensors Vol. 12; no. 6; p. 112
• Main Authors: Nascimento, Amanda B, de Faria, Lucas V, Matias, Tiago A, Lopes, Osmando F, Muñoz, Rodrigo A A
• Format: Journal Article
• Language: English
• Published: Basel MDPI AG 01.06.2024
• Subjects: amperometric detection; Amperometry; Biomarkers; Carbon; Chloride; Diabetes; Electrical measurement; Electrodes; Electrons; enzymeless; ferrites; glucometer; Glucose; Multi wall carbon nanotubes; nanocomposite; Nanomaterials; Nanotubes; Nickel; Nickel ferrites; Nitrates; Raman spectroscopy; Sensors; Sodium; Spectrum analysis; Uric acid; Urine; Brazil; United States > US
• ISSN: 2227-9040
• DOI: 10.3390/chemosensors12060112

The development of sensitive and selective analytical devices for monitoring glucose levels (GLU) in biological fluids is extremely important for clinical diagnostics. In this work, we produced a new composite based on NiFe2O4 and multi-walled carbon nanotubes (MWCNT), called NiFe2O4@MWCNT, to be applied as a non-enzymatic amperometric sensor for GLU. Both NiFe2O4 and NiFe2O4@MWCNT composites were properly characterized by XRD, SEM, FTIR, and Raman spectroscopy, which confirmed that the composite was successfully prepared. A glassy-carbon electrode (GCE) modified with NiFe2O4@MWCNT was investigated by cyclic voltammetry and applied for the amperometric GLU detection using batch-injection analysis (BIA). A linear working range between 50 and 600 µmol L−1 GLU with a significant increase in sensitivity (3-fold) in comparison with MWCNT/GCE was verified, with a detection limit of 36 µmol L−1. Inter-electrode measurements (n = 4, RSD = 10%) indicated that the sensor fabrication is reproducible. Furthermore, the proposed non-enzymatic sensor was selective even in the presence of other biomarkers found in urine. When applied to synthetic urine samples, recovery levels between 84 and 95% confirmed analytical accuracy and the absence of sample matrix effect. Importantly, the developed approach is simple (free of biological modifiers), fast (77 injections per hour), and practical (high-performance tool), which are suitable features for routine analyses.