A novel conductance glucose biosensor in ultra-low ionic strength solution triggered by the oxidation of Ag nanoparticles.

Analytica chimica acta

PubMedID: 26388373

Song Y, Chen J, Liu H, Li P, Li H, Wang L. A novel conductance glucose biosensor in ultra-low ionic strength solution triggered by the oxidation of Ag nanoparticles. Anal Chim Acta. 2015;891144-50.
A simple, sensitive and effective method to detect glucose in ultra-low ionic strength solution containing citrate-capped silver nanoparticles (CCAgNPs) was developed by monitoring the change of solution conductance. Glucose was catalyzed into gluconic acid firstly by glucose oxidase in an O2-saturated solution accompanied by the reduction of O2 into hydrogen peroxide (H2O2). Then, CCAgNPs was oxidized by H2O2 into Ag(+) and the capping regent of citrate was released at the same time. All these resulted Ag(+), gluconic acid and the released citrate would contribute to the increase of solution ionic strength together, leading to a detectable increase of solution conductance. And a novel conductance glucose biosensor was developed with a routine linear range of 0. 06-4. 0 mM and a suitable detection limit of 18. 0 µM. The novel glucose biosensor was further applied in energy drink sample and proven to be suitable for practical system with low ionic strength. The proposed conductance biosensor achieved a significant breakthrough of glucose detection in ultra-low ionic strength media.