Rapid and highly sensitive visual detection of oxalate for metabolic assessment of urolithiasis via selective recognition reaction of CdTe quantum dots.

Urolithiasis is a common disease that affects 5% to 8.8% of the world population with high recurring frequency. Therefore, there is an urgent need for the rapid and efficient diagnostics of urolithiasis. In this study, we developed a quantum dots (QDs)-based sensor for detecting urolithiasis oxalate. Urolithiasis oxalate was quantified by reducing Cu2+ to Cu+, which can be selectively recognized by CdTe QDs. The homogeneous sensing system shows high sensitivity for oxalate detection in the range of 0.1 μM to 10 mM within 6 min; moreover, the visual detection of 10 μM oxalate could be achieved by the naked eye. Our method was tested on 53 clinical samples; it showed 100% specificity and sensitivity for calcium oxalate urolithiasis compared with clinical diagnosis, even for hematuria samples. Furthermore, this method can be expanded to other wide range of biochemistry applications for medical diagnosis and point-of-care testing.