Nanotubes Sniff Out Kidney Failure

Getting tested for kidney disease could one day be as easy as exhaling, thanks to new technology developed by researchers in Israel. Diagnosing renal illnesses currently involves urine and blood tests, with the most definitive diagnoses requiring a kidney biopsy. Hossam Haick and coworkers at Technion—Israel Institute of Technology have shown they can differentiate between healthy rats and rats with chronic renal failure by using nanotube-based sensors to test the rats' breath for specific volatile organic compounds (ACS Nano, DOI: 10.1021/nn9001775). Using gas chromatography and mass spectrometry, the researchers identified 15 compounds in the breath of both healthy and diseased rats, as well as 27 compounds that only appear in the breath of rats with chronic renal failure. They then designed an array of chemiresistive networks of single-walled carbon nanotube sensors capable of distinguishing between the two distinct breath signatures. Such discrimination "provides expectations for future capabilities for diagnosis, detection, and screening various stages of kidney disease," the researchers note, "especially in the early stages of the disease, where it is possible to control blood pressure and protein intake to slow the progression."