Gold nanoparticle sensors for detecting chronic kidney disease and disease progression

Aim: To study the feasibility of a novel nanomedical method that utilizes breath testing for identifying chronic kidney disease (CKD) and disease progression. Materials & Methods: Exhaled breath samples were collected from 62 volunteers. The breath samples were analyzed using sensors based on organically functionalized gold nanoparticles, combined with support vector machine analysis. Sensitivity and specificity with reference to CKD patient classification according to estimated glomerular filtration rate were determined using cross-validation. The chemical composition of the breath samples was studied using gas chromatography linked with mass spectrometry. Results: A combination of two to three gold nanoparticles sensors provided good distinction between early-stage CKD and healthy states (accuracy of 79%) and between stage 4 and 5 CKD states (accuracy of 85%). A single sensor provided a distinction between early and advanced CKD (accuracy of 76%). Several substances in the breath were identified and could be associated with CKD-related biochemical processes or with the accumulation of toxins through kidney function loss. Conclusion: Breath testing using gold nanoparticle sensors holds future potential as a cost-effective, fast and reliable diagnostic test for early detection of CKD and monitoring of disease progression.