A nanoplasmonic platform can be used for the detection and quantification of multiple HIV subtypes in whole blood with localized surface plasmon resonance. Among other things, this nanoplasmonic platform provides a viable way to detection and quantification of viral load at a point of care with significantly less cost, time, and laboratory resources than existing methods of detection. Although an example of HIV detection in whole blood is provided, the nanoplasmonic platform is adaptable to detect other pathogens and infectious agents or macromolecules.