Non-Invasive glucose monitoring: gold and silver nanoparticles in saliva analysis

Introduction : Testing blood sugar levels can be painful and uncomfortable due to the need for blood draws. Nanoparticle studies have demonstrated unique properties that enable them to interact with glucose in ways larger molecules cannot. Our project is an attempt to show that glucose levels can be accurately measured from human saliva using nanoparticles.

Method :Gold and silver nanoparticles were synthesized using gold salts and silver nitrate, with sodium borohydride used as the reducing agent and sodium citrate as the stabilizer. Glucose solutions were mixed with gold nanoparticles in a 1:1 ratio. Heat was applied to accelerate the reaction before silver nanoparticles were introduced. Various tests were conducted, including comparing samples with and without heat, different concentrations of nanoparticles, and using a reducing agent without a stabilizer. The UV absorption spectra of the resulting solutions were measured to evaluate the outcomes.

Results : Gold and silver nanoparticles were stable, showing interaction with glucose via decreased UV absorption. The UV spectrum displayed peaks for both metals. Higher glucose concentrations led to lower absorbance. Heating before adding silver enhanced the gold–glucose reaction, reducing the gold peak and increasing the silver peak due to less glucose availability for the silver reaction.

Conclusion: This project enabled the detection of blood glucose levels using saliva rather than the usual method, which can be uncomfortable. We added gold and silver nanoparticles to different glucose concentrations, and analyzed the UV absorption spectra. This offers a less intrusive approach for obtaining blood sugar levels.