Nitric oxide (NO) is a highly reactive signaling molecule with expanding applications in vascular biology, infectious disease, wound healing, cancer, biomaterials, and therapeutic drug delivery. Yet translation of NO research is often limited by a fundamental methodological problem: NO is short-lived and difficult to quantify directly, while many studies and emerging technologies rely on surrogate measurements that may not be adequately validated against established analytical methods. This Topical Collection will bring together rigorous, reproducible methods for measuring NO and its metabolites and for characterizing the delivery, pharmacokinetics, biodistribution, and biological activity of NO-generating therapeutics.

The collection will highlight ozone-based chemiluminescence, chemical reduction of nitrate and nitrite, electrochemical and spectroscopic approaches, mass spectrometry, biosensors, and validated strategies for blood, urine, saliva, tissue, cerebrospinal fluid, and exhaled samples. Studies comparing wearable, point-of-care, or noninvasive technologies with reference laboratory methods will be encouraged. The collection will also include protocols for NO-releasing compounds, biomaterials, topical formulations, inhaled systems, nanoparticles, and targeted molecular carriers, emphasizing release kinetics, stability, dose-response relationships, pharmacokinetics, and tissue distribution.

By connecting analytical validation with therapeutic development, this collection will provide practical methods to determine not simply whether an intervention is associated with “nitric oxide,” but how much NO-related signal is generated, where it is delivered, how long it persists, and whether those measurements predict biological or clinical effects. The goal is to strengthen reproducibility and accelerate the translation of nitric oxide biology into credible diagnostics and therapies.