Iron oxide immobilized lipase bioconjugate platform for sensing of triglycerides in biological samples

Abstract

As a major biomarker in several health conditions, an efficient detection strategy to monitor triglyceride (TGs) level is imperative. In this study, enzyme-based triglyceride detection platform is reported by employing surface functionalized iron oxide nanoparticles (IONPs). The green synthesis method (using green tea extract) was adopted for the synthesis of IONPs exhibiting magnetic properties. The synthesized nanoparticle was characterized using SEM, FT-IR and UV–Vis spectroscopy. The SEM data confirmed the synthesis of spherical nanoparticles with an average size of 200 nm. Moreover, the additional coating of aspartate made the immobilization of biomolecule lipase on the IONPs more stable and was confirmed via the acquired data from SEM. The surface functionalization of IONPs using aspartic acid was confirmed by FT-IR spectra. Enzyme immobilization was performed by adding glutaraldehyde as the crosslinker, leading to formation of a nanoparticle-enzyme bioconjugate. The resultant bioconjugate was used for colorimetric estimation of triglyceride in biological samples using palmitic acid as the standard and methyl red as the indicator. The designed bioconjugate exhibited accuracy of 7.5 folds. The nanoparticle-enzyme bioconjugate platform renders a simple, economical, and easy-to-use biosensing approach with higher stability and activity when compared to its soluble counterpart.