Multiplex protein detection

Covalent Coupling—A Tool for Multiplex Protein Detection... 

ESI-MS for Multiplex Protein Detection in Array Format by Using Metal-Antibody Conjugates... 

Figure 12.14 Schematic representation of the biobaicode assay for multiplexed protein detection. The general concept for multiplexed DNA detection is similar, with the appropriate recognition elements. (Reproduced with permission from S. I. Stoeva et al., J. Am. Chem. Soc. 2006, 128, 8378-8379. Copyright 2006 American Chemical Society.) (See color insert.)...

Figure 12.14 Schematic representation of the biobatcode assay for multiplexed protein detection. The general concept for multiplexed DNA detection is similar, with the appropriate recognition elements.

The next section discusses the nature and significance of biomarker proteins for cancer, followed by a section reviewing the use of nanoparticles in sensors and detection protocols. The section following discusses the combination of nanoscience-assisted sensing with microfluidics for multiplexed protein detection. We end the chapter with an overview and comments on the future of cancer diagnostics based on biomarker detection. 

Multiplexed protein detection using the above approaches has also been developed [38]. One approach is to use bar code labeling secondary antibodies with distinct nanoparticles with easily detectable electrochemical characteristics, e.g. different dissolvable metals or quantum dots (Qdots) that can be dissolved to give ions with different reduction potentials. 

Array detectors, in general, clearly have an important role to play in personalization of medical care. A recent example of work in this field is the development of nanobiochips for multiplexed protein detection of three cancer biomarkers, namely, carcinoembiyonic antigen, cancer antigen 125, and Her-2INeu in serum and saliva specimens. ... 

Reprinted (adapted) with permission from L. Ma, C. Wang, Y. Hong, M. Zhang, M. Su, Thermally addressed immunosorbent assay for multiplexed protein detections using phase change nanoparticles, Anal5dical Chemistry 82 (2010) 1186-1190. Copyright 2010 American Chemical Society. 

The capability of ZnO nanomaterials for reliable, multipurpose, and multiplexed fluorescence detection of interacting protein molecules is tested with a variety of model proteins [64]. As a proof-of-concept, different pairs of proteins are sequentially introduced to NR platforms and screened for fluorescence. The approach involving ZnO nanostructures in the enhanced fluorescence detection is then extended to identify the presence or absence of multiple protein / protein interactions on the same substrate. In some cases, microfluidic chambers made out of PDMS are used in order to carry out multiple protein interaction assays on the same ZnO NR supports. 

Silicon nanowires incorporated into arrays provide label-free, multiplexed electrical detection of cancer protein biomarkers such as prostate-specific antigen at femtomolar concentrations with high sensitivity in clinically relevant serum samples [7]. Real-time assays of the binding, activity, and small-molecule inhibition of telomerase could be performed with this technique using unamplified extracts from as few as 10 tumor cells. This opens up substantial possibilities for diagnosis and treatment of cancer. 

Microfluidics coupled to bioanalytical devices has the potential to improve multiplexing and signal/noise, consume less expensive reagents and provide a degree of automation. In this section, we briefly summarize recent efforts to couple microfluidics to nanoparticle-based protein immunoassays for multiplexed biomarker detection. A recent example involves a 16-sensor electrochemical chip... 

Rusling, J.R 2013. Multiplexed electrochemical protein detection and translation to personahzed cancer diagnostics. AwaZ. Chem. 85 5304-5310. 

Nelson, R. W. Jarvik, J. W. Taillon, B. E. Tubbs, K. A. BIA/MS of epitope-tagged peptides directly from E. coli lysate Multiplex detection and protein identificatin at low-femtomole to subfemtomole levels. Anal. Chem. 1999, 71, 2858-2865. 

The concept is demonstrated for a simultaneous immunoassay of (32-microglobulin, IgG, bovine serum albumin, and C-reactive protein in connection with ZnS, CdS, PbS, and CuS colloidal crystals, respectively (Fig. 14.6). These nanocrystal labels exhibit similar sensitivity. Such electrochemical coding could be readily multiplexed and scaled up in multiwell microtiter plates to allow simultaneous parallel detection of numerous proteins or samples and is expected to open new opportunities for protein diagnostics and biosecurity. 

We have shown in the past few years that due to their finite size (comparable to an average protein), CdSe-ZnS core-shell nanocrystals capped with a thin layer of dihydrolipoic acid ligands provide excellent nanoscale scaffolds ( nanoscaffolds ) for attaching several proteins on their surfaces. QD-protein conjugates were used to design multiplexed immunoassays to detect soluble toxins. 

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