Emerging protein array technologies for proteomics

Numerous efforts have been made to understand fundamental biology of diseases based on gene expression. However, the relationship between gene expression and onset of disease often remains obscure. The great advances in protein microarrays allow us to investigate this unclear question through protein profiles, which are regarded as more reliable than gene expressions to serve as the harbinger of disease onset or as the biomarker of disease treatment monitoring. The authors review two relatively new platforms of protein arrays, along with an introduction to the common basis of protein array technologies. Immobilization of proteins on the surface of arrays and neutralizing reactive areas after the immobilization are key practical issues in the field of protein array. One of the emerging protein array technologies is the magneto-nanosensor array, where giant magnetoresistive sensors are used to quantitatively measure the analytes of interest, which are labeled with magnetic nanoparticles. Similar to giant magnetoresistive sensors, several different ways of utilizing magnetic properties for biomolecular detection have been developed and are reviewed here. Another emerging protein array technology is nucleic acid programmable protein arrays, which have thousands of protein features directly expressed by nucleic acids on the array surface. The authors anticipate that these two emerging protein array platforms can be combined to produce synergistic benefits and open new applications in proteomics and clinical diagnostics.