Mercaptopropionic acid capped cadmium selenide quantum dots based urea Biosensor

Here a simple fluorescence Turn-On based strategy is used for the determination of urea using water soluble mercaptopropionic acid capped cadmium selenide quantum dots (MPA-CdSe QDs). These MPA-CdSe QDs were pH sensitive and this property is used for urea detection after the immobilization of urease. The principle of detection is to measure and correlate the enhancement of fluorescence intensity of MPA-CdSe QDs caused by the enzymatic reaction between urease with urea and release of ammonia. Ammonia release leads to raise in the pH value which turns on the fluorescence intensity of MPA-CdSe QDs in the presence of increasing concentration of urea varying from 1 to 120 mM with a lower detection limit of 1 mM.

Automated summary

A fluorescence Turn-On based strategy using MPA-CdSe QDs was utilized for urea determination, with a detection range from 1 to 120 mM and a lower detection limit of 1 mM. The pH sensitivity of MPA-CdSe QDs was key in detecting urea through the enzymatic reaction with urease and the release of ammonia.