Non-enzymatic sensing of kidney dysfunction biomarker using pectin – MWCNT nanocomposite

Abstract

Creatinine, a biomarker for kidney dysfunction, is a molecule created within skeletal muscles as a product of physical activities. The normal physiological concentration of creatinine is 40–150 μM, beyond which it will lead to kidney dysfunction. Thus monitoring of creatinine level becomes more important for normal functioning of the body. In the currently available enzymatic studies, three enzymes were required for sensing creatinine. As the enzymatic electrochemical sensing studies are tedious and have several drawbacks, non-enzymatic sensing of creatinine using a biopolymer based sensor was proposed in the present study. Pectin (PEC), a naturally occurring polysaccharide, was extracted from musk melon peels and it was used for the modification of MWCNT. The prepared bionanocomposite was characterized using UV–vis, FT-IR, XRD, RAMAN, SEM, and TGA techniques. The bionanocomposite was effectively incorporated into the carbon paste matrix (CPE) and fabricated as a working electrode (CPE/PEC-MWCNT). The enhanced surface properties like electro active surface area A (0.0329 cm2), surface concentration Γ (0.0503 × 10−6 mol cm−2), diffusion coefficient D0 (0.0964 cm2 s−1), heterogeneous rate constant ks (0.3736 s−1) of CPE/PEC-MWCNT as compared to that of GCE (Glassy Carbon electrode), CPE, CPE/PEC and CPE/MWCNT electrodes, suggested enhanced electrochemical functionalization, competent diffusion of creatinine and hence effective electron transfer at the newly fabricated electrode surface. The electrode was also effectively utilized for the sensing of creatinine in urine samples.