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

Enzyme-based triglyceride detection platform is described as an efficient approach for biosensing of triglyceride concentration in biological fluids. Enzyme lipase isolated from a lipolytic bacterial strain was immobilized on aspartate-functionalized iron oxide nanoparticles (IONPs). The green synthesis method was adopted for the synthesis of IONPs exhibiting magnetic properties. The synthesized aspartate-functionalized IONPs were used as a suitable matrix for lipase immobilization leading to formation of a nanoparticle-enzyme bioconjugate. The formation of the nanoparticle, functionalized nanoparticle, and bioconjugate was validated with the help of analytical techniques like spectroscopy, scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR). 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 average size of nanoparticle was found to be 200 nm. The designed bioconjugate resulted into determination of triglyceride in biological sample with an accuracy of 7.5 folds. The nanoparticle-enzyme bioconjugate platform renders a simple, economical, and easy-to-use biosensing device with higher stability and activity when compared to its soluble counterpart.