Enzyme bioconjugated PAMAM dendrimers for estimation of glucose in saliva

This research work intended to prepare and characterize novel dendrimer-based biosensors with an improved response for the detection of glucose in saliva. The nanoparticles of Fe3O4, a core material, encapsulated in PAMAM dendrimers to immobilize glucose oxidase in the presence of cross-linking agent, glutaraldehyde. Fe3O4 nanoparticles were synthesized by oxidative reaction of ferrous chloride and potassium hydroxide. A solvent-free or green chemistry concept was used to prepare PAMAM dendrimers (G4) using Michael addition and amidation reactions where ethylene diamine and methyl methacrylate were used as reactants. The particle size of Fe3O4 nanoparticles and dendrimers were in the range of 20-30 nm and 30-40 nm, respectively. Glucose was detected by photofluorometer using Tris(1, 10-phenanthroline) ruthenium (II) chloride hydrate [TPR(II)CH] as an indicator. The biosensor showed a response in 4-6 min both in the presence and absence of artificial saliva. The behavior of biosensor showed an increase in fluorescence intensity for the concentrations of glucose (5, 10, 15, and 20 ppm). Fourier-transform infrared spectroscopy and differential scanning calorimetry studies confirmed the synthesis of Fe3O4 nanoparticle and acted as a core of PAMAM dendrimers. This potential approach is a simple, cost-effective, and reproducible for noninvasive glucose detection in saliva.

Automated summary

The research successfully prepared and characterized novel dendrimer-based biosensors for the detection of glucose in saliva. These biosensors showed improved response time and sensitivity, accurately detecting glucose concentration in a short period of time.