Sensitive electrochemical immunoassys based on nanoparticle labels has been developed for the detection of protein biomarker, biomarker of recombinant human tumor necrosis factor-a(TNF-a). The use of functional quantum dots, carbon nanotubes, and silica nanoparticles as labels for signal amplification will be discussed. This method is simple, selective, and reproducible for trace biomarker analysis. A remarkable LOD has been achieved through signal amplification by functionalized nanoparticle labels. The work demonstrates the feasibility of developing an inexpensive, sensitive, and portable device for multiplexed diagnosis of different protein biomarkers.