A non-enzymatic electrochemical approach for l-lactic acid sensor development based on CuO·MWCNT nanocomposites modified with a Nafion matrix
Copper oxide decorated multi-walled carbon nanotube nanocomposites (CuO·MWCNT NCs) were prepared using a simple wet-chemical technique in basic medium. The CuO·MWCNT NCs were examined by using various analytical techniques, for example ultraviolet-visible spectroscopy (UV-visible), Fourier transform infrared spectroscopy (FTIR), X-ray powder diffraction (XRD), field emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), and X-ray photoelectron spectroscopy (XPS). An L-lactic acid sensor was developed with modification of a thin layer of nanocomposite onto a flat glassy carbon electrode (GCE, surface area = 0.0316 cm2). Analytical sensor performances for example sensitivity, limit of detection (LOD), limit of quantification (LOQ), linear dynamic range (LDR), durability, interference effect examination, and real sample analysis of the synthesized L-lactic acid sensor were achieved through a dependable current–voltage procedure. The calibration curve of the GCE/CuO·MWCNT NCs/NAF sensor was linear (R2 = 0.9891) over an extensive range of L-lactic acid concentrations (100.0 pM–100.0 mM). The sensitivity (633.0 pA μM−1 cm−2), LOD (≈88.5 pM), LOQ (295.0 mM), and LDR (100.0 pM–10.0 mM) of the L-lactic acid sensor were determined correspondingly from the calibration curve. Preparation of CuO·MWCNT NCs using a wet-chemical procedure is excellent progression for the expansion of nanocomposite based sensor development in support of enzyme-free discovery of bio-molecules in healthcare fields. This expected GCE/CuO·MWCNT NCs/NAF sensor was applied for the specific identification of L-lactic acid in real serum samples and provided reasonable and acceptable results.