Electrochemical Biosensor for the Detection of Amygdalin in Apple Seeds with a Hybrid of f-MWCNTs/CoFe2O4 Nanocomposite

Background: Amygdalin is a natural compound known for curing cancer. It is seen in several plants including in bitter almonds, apricots, peaches, apples, and plum seeds (kernels). Amygdalin is a toxic molecule containing a nitrile group, due to which toxic cyanide anion releases by the action of a β-glucosidase. The consumption of amygdalin may lead to cyanide poisoning in the human body. Therefore, for the first time, this work is aimed at developing a novel electrochemical biosensor for the detection of Amygdalin (AMG) in apple seed samples. Methods: The proposed electrochemical biosensor was fabricated by immobilizing cytochrome c (Cyt c) on a Glassy Carbon Electrode (GCE) with nanocomposite of cobalt ferrite nanoparticles (CoFe2O4 NPs) and functionalised multiwalled carbon nanotubes (f-MWCNTs). The characterization of the synthesized nanocomposite was performed with FTIR, TEM, TGA/DSC, and XRD techniques. Moreover, various experimental parameters such as the effect of pH, deposition time, sweep rate, potential, and enzyme incubation time and interference were also studied. Results: The fabricated biosensor enhanced the peak current by 10-folds compared to unmodified GCE. Under optimized experimental conditions, the biosensor exhibited linear response from 2 to 20 μM, with a linear regression equation Ipa (μA) = 8.4989 c + 6.6307 (R² = 0.9927). The LOD’s and LOQ’s were found to be 0.0112 μM and 0.2213 μM, respectively. Conclusion: The designed biosensor was successfully applied for the analysis of AMG content in the apple seed samples. The outcomes of this study identify the efficient electrocatalytic activity of the fabricated nanocomposite as significant electronic factors as major contributors to the electron transfer mechanism, with promising scope for the design of biosensor to sense toxic molecules.