NON-TECHNICAL SUMMARY: Many of the world’s most dangerous bacteria carry hidden warning labels on their surface—special types of molecules called lipopolysaccharides. Detecting this molecular badge is one of the most reliable ways to identify harmful microbes before they have a chance to spread. However, most current technologies for detecting lipopolysaccharides are too slow, too costly, or not sensitive enough to reliably protect food, water, and healthcare systems. This project tackles that challenge by creating innovative materials called nanoparticles, which are so small that thousands could fit across a single human hair. These gold and silver nanoparticles are carefully shaped and engineered to recognize and bind to lipopolysaccharide molecules, similar to how a key fits into a lock. By precisely controlling the size and surface features of these nanoparticles, the research aims to develop rapid, accurate, and affordable sensors for bacterial contamination. These tools have the potential to offer early warnings about invisible threats, improving public health responses before outbreaks occur. By advancing the science of material design and developing better ways to protect public systems, this work directly supports national priorities in health, security, and scientific innovation. The knowledge and technologies generated through this research could contribute to a safer, healthier future, and will train the future STEM workforce. Finally, this work includes develo