Standard photolithographic techniques and a nitric oxide (NO) selective xerogel polymer were utilized to fabricate an amperometric NO microfluidic sensor with low background noise and the ability to analyze NO levels in small sample volumes (~250 μL). The sensor exhibited excellent analytical performance in phosphate buffered saline, including a NO sensitivity of 1.4 pA nM−1, a limit of detection (LOD) of 840 pM, and selectivity over nitrite, ascorbic acid, acetaminophen, uric acid, hydrogen sulfide, ammonium, ammonia, and both protonated and deprotonated peroxynitrite (selectivity coefficients of −5.3, −4.2, −4.0, −5.0, −6.0, −5.8, −3.8, −1.5, and −4.0 respectively). To demonstrate the utility of the microfluidic NO sensor for biomedical analysis, the device was used to monitor changes in blood NO levels during the onset of sepsis in a murine pneumonia model
