Fabrication of Potentiometric Glucose Biosensor Based on Two Variant Dimensions of Green Synthesized Silver Nanostructures as a Single Nanohybrid Compartment—A Green Approach

Abstract

In this work, silver nanohybrids (AgNHs) comprising of two different dimensions of nanostructures i.e., nanorods (zero dimensions) and nanoparticles (one dimensions), are synthesised. As a green chemical approach, we have used the leaf extracts of Cassia occidentalis (coffee senna) for the synthetic protocol of these variant dimensions of nanostructures. The as synthesized nanostructures were explored for the fabrication of a nano-hybrid based potentiometric glucose biosensor. A conducting polymer, polypyrrole (PPy) is used for the strong adsorption of the nanohybrid on the graphite (Gr) electrode. The resulting composite matrix (Gr/PPy/AgNHs) is further modified with glucose oxidase (GOx) enzyme to obtain Gr/PPy/AgNHs/GOx biosensor for the electrochemical detection of glucose. The synergetic effect of the materials employed in development of bio-electrode resulted in an efficient glucose biosensor with a low detection limit (55.3 μM), high sensitivity (69.72 μAmM –1cm–2) and a wide linear range of 0.2–29 mM. These results validate a successful electrochemical sensor with superior analytical performance in comparison to sensors cited in literature. The proposed biosensor also exhibits good storage stability, reproducibility and remains unaffected by some of the common interferents present in the biological sample. The developed biosensor is also evaluated for glucose analysis in real samples with a high percentage recovery (97%) thus validating the possibility of its usage in biomedical applications.