title: Ultrasensitive assays for proteins.
abstract: Proteins are essential components of organisms and are involved in a wide range of biological functions. There are increasing demands for ultra-sensitive protein detection, because many important protein biomarkers are present at ultra-low levels, especially during the early stages of disease. Measuring proteins at low levels is also crucial for investigations of the protein synthesis and functions in biological systems. In this review, we summarize the recent developments of novel technology enabling ultrasensitive protein detection. We focus on two groups of techniques that involve either polymerase amplification of affinity DNA probes or signal amplification by the use of nano-/micro-materials. The polymerase-based amplification of affinity DNA probes indirectly improves the sensitivity of protein detection by increasing the number of detection molecules. The use of nano-/micro-materials conjugated to affinity probes enhances the measurement signals by using the unique electrical, optical, and catalytic properties of these novel materials. This review describes the basic principles, performances, applications, merits, and limitations of these techniques.
authors.affiliation: Analytical and Environmental Toxicology, Department of Laboratory Medicine and Pathology, Faculty of Medicine and Dentistry, University of Alberta, Edmonton, Alberta, Canada T6G 2G3.
authors.forename: Hongquan
authors.initials: H
authors.lastname: Zhang
authors.forename: Qiang
authors.initials: Q
authors.lastname: Zhao
authors.forename: Xing-Fang
authors.initials: XF
authors.lastname: Li
authors.forename: X Chris
authors.initials: XC
authors.lastname: Le
mesh_terms: D000818:Animals; D015342:DNA Probes; D006801:Humans; D007118:Immunoassay / Q000379:methods; D015336:Molecular Probe Techniques; D036103:Nanotechnology; D016133:Polymerase Chain Reaction / Q000379:methods; D040081:Protein Array Analysis; D011506:Proteins / Q000032:analysis*; D012680:Sensitivity and Specificity
chemical_list: D015342:DNA Probes; D011506:Proteins