Fans of the sci-fi series Star Trek are familiar with the show’s fictional “tricorders,” handheld devices used for sensor scanning and data analysis and recording. Yet these futuristic instruments are now, in a sense, entering the real world due to the advent of biosensors, devices that transform the detection of biological elements—antibodies, nucleic acids, cell receptors, enzymes, among others—into signals (e.g., optical, electrochemical) that can be more easily measured and quantified. The technology behind this modern-day measuring equipment is surface plasmon resonance (SPR), a process through which electrons on a metal surface are excited by a polarized light source, creating charge-density waves called plasmons. These plasmons then bend the light at a specific angle (known as the resonance angle) that is picked up through a detector. As molecules bind and dissociate from the metal surface, the resonance angle changes, giving an interaction profile (including binding kinetics, specificity, concentration, and affinity) that is recorded in real time. The possibilities for this technology include proteomics, immunogenicity, and drug discovery, but really are limitless. However, the best use for SPR is precision medicine. This tool could help to more quickly identify molecules or compounds that could aid in treatment of diseases. Conversely, it could also help pinpoint which patients would respond best to a particular drug or vaccine. Included in this booklet are articles from Science, Science Translational Medicine, and Science Signaling that detail the prospects for SPR technology.