Non-enzymatic glucose detection with Screen-Printed Chemiresistive sensor using green synthesised silver nanoparticle and multi-walled carbon nanotubes-zinc oxide nanofibers.

Non-enzymatic Screen-Printed Chemiresistive Interdigitated Electrodes (SPCIE) were designed and fabricated using a low-cost screen-printing method for detection of the glucose. The Interdigitated Electrodes (IDE) pattern was printed using conductive graphene ink on the glossy surface of the photo paper. The proposed glossy photo paper-based SPCIE are functionalized with Multi-walled Carbon Nanotubes-Zinc Oxide (MWCNTs-ZnO) nanofibers to create the chemiresistive matrix. Further, to bind these nanofibers with the graphene electrode surface, we have used the green synthesized silver nanoparticles (AgNPs) with Banana Flower Stem Fluid (BFSF) as a binder solution. AgNPs with BFSF form the Conductive Porous Natural Binder Layer (CPNBL). It does not allow to increase the resistivity of the deposited material on graphene electrodes and also keeps the nanofibers intact with paper-based SPCIE. The synthesized material of MWCNT-ZnO nanofibers and green synthesized AgNPs with BFSF as a binder were characterized by Ultraviolet-visible spectroscopy (UV-Vis), Scanning Electron Microscope (SEM), X-Ray Diffraction (XRD), and Fourier-Transform Infrared Spectroscopy (FTIR). The amperometric measurements were performed on the proposed SPCIE sensor to detect the glucose sample directly. The innovative paper-based SPCIE glucose sensor exhibits a linear corelation between current measurements and glucose concentration in the range between 45.22 µM - 20 mM, with a regression coefficient (R2) of 0.9902 and a lower Limit of Detection (LoD) of 45.22 µM (n=5). The sensitivity of the developed SPCIE sensor was 2178.57 µAmM-1cm-2, and the sensor's response time determined was approximately equal to 18 seconds. The proposed sensor was also tested for real blood serum sample, and Relative Standard Deviation (RSD) was found equal to 2.95%.