InP/ZnS Nanocrystals as Fluorescent Probes for the Detection of ATP

Abstract

This article reports on a study on fluorescence adenosine triphosphate (ATP) detection by InP/ZnS quantum dots (QDs). We present a spectroscopic analysis displaying the effect of enzymatic reactions of glucose oxidase (GOX) and hexokinase (HEX) on the InP/ZnS quantum dots at physiological pH. The InP/ZnS quantum dots act as glucose sensors in the presence of GOX, Glu and ATP, and their luminescence quenches during the release of hydrogen peroxide from the reaction. However, in the presence of adenosine 5′ triphosphate, glucose, and HEX, a significant photobrightening of the InP/ZnS QDs is recorded. This is dependent on the concentration of ATP in the sample. The relationship between the ATP and the emission intensity of InP/ZnS nanocrystals is linear. The present results are the first to report the effect of different by-products released by these enzymatic reactions on the fluorescence of the InP/ZnS QDs.