Biomarker detection chips

Figure 7.10 Biomarker detection with an LC-MS chip. (A) Base-peak chromatogram of SCX fraction 7 of the MCF7 protein digest showing the distribution of putative biomarker peptides across the LC-MS run. (Adapted with permission from ref. 33). (B) Mass spectrum that enabled the selection of a PCNA peptide for collision-induced dissociation. Conditions were the same as for Figure 7.9.

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... 

Chen YQ, Bi F, Wang SQ, Xiao SJ, Liu JN (2008) Porous silicon affinity chips for biomarker detection by MALDI-TOF-MS. J Chromatogr B Anal Techno Biomed Life Sci 875 502-508... 

Ruetschi, U., Rosen, A., Karlsson, G., Zetterberg, H., Rymo, L., Hagberg, H., and Jacobsson, B. Proteomic analysis using protein chips to detect biomarkers in cervical and amniotic fluid in women with intra-amniotic inflammation. J Proteome Res, 4 2236-2242, 2005. 

The development of an automated selection process, the intrinsic properties of aptamers combined with their conversion into signaling elements, and the ease of conjugating oligonucleotides on different surfaces make them appropriate for their use in microarray formats. Interest in aptamer chips was outlined long ago (Brody and Gold, 2000). They could be used for the identification and quantification of multiple proteins or biomarkers. There are still few reports on the development of microarray-based aptamer assays. Detection of the analyte... 

Surface-enhanced laser desorption ionization (SELDI) uses so-called protein chips for the detection of peptides and proteins from complex biological fluids such as blood or urine, often for the identification of diagnostic biomarkers for specific carcinomas [156, 157]. These protein chips can contain various media for positive or negative ion exchange or reverse-phase chromatography, as well as specific antibodies or DNA. The functionaUzed surface is immobihzed on a MALDl sample plate for the selective enrichment of constituents of the complex mixture applied, whereas the not bound supernatant is removed by washing. Unfortunately, a large number of unsubstantiated claims for the detection of disease-related biomarkers has discredited this approach, mostly as a result of poor mass spectrometric performance. 

Tang, C.K., Vaze, A., Rusling, J.F. Fabrication of immunosensor microwell arrays from gold compact discs for ultrasensitive detection of cancer biomarker proteins. Lab on a Chip (2011, in press). doi 10.1039/ClLC20833K... 

M.-I. Mohammed, M.RY. Desmulliez, Lab-on-a-chip based immunosensor principles and technologies for the detection of cardiac biomarkers a review. Lab on a Chip 11 (2011)569-595. 

Azmi et al. (2014) created a handheld, POC system, in which a silicon nanowire biosensor (SiNW) chip is wire-bonded to a bio-smartcard and subsequently slotted into an electronic readout device. This sensor detects an oxidative stress biomarker, 8-hydroxydeoxyguanosine (8-OHdG), which has been related to prostate cancer risk. 

---