Early detection of cancer is crucial for its prevention and treatment. Normal techniques have low sensitivity and can only detect solid tumors with millimeter diameters. The advances in molecular biology open up new opportunities of early detection using molecular abnormalities as biomarkers. However, a major challenge for biomarker (DNA, protein)-based cancer detection is that most biomarkers are not effective, have low concentrations, exist at different stages and need extensive effort to make samples. One way to enhance the diagnosis accuracy is to use multiple cancer biomarkers, where even if each biomarker has low power, their combination can provide accurate information. On the other hand, although many different types of nanoparticles have been used to detect cancer biomarkers at low concentrations, the multiplicities of nanoparticle-based detections are limited due to their narrow detection ranges and broad peaks. Only one or several types of biomarkers could be detected at one time, and screening one sample for multiple biomarkers takes a long time, agents, and effort. This project will study a novel technique for the highly sensitive detections of multiple protein biomarkers using encapsulated nanoparticles of phase change materials (nano-PCM) as thermal barcodes. During the solid-liquid phase changes, the nanoparticles adsorb heat energy without temperature rise, and show sharp melting peaks. A variety of phase change nanoparticles can be made that their sharp melting peaks distribute over a large range of temperature, meaning the detection multiplicity can be enhanced greatly.