02 Jun Real-time and label-free detection of exosomes on chip
Abstract
“Exosomes are highly important in clinical diagnosis due to their high homology with their parental cells. However, conventional exosome detection methods still face the challenges of expensive equipment, low sensitivity, and complex procedures. Field effect transistors (FETs) are not only the most essential electronic component in the modern microelectronics industry but also show great potential for biomolecule detection owing to the advantages of rapid response, high sensitivity, and label-free detection. In this study, we proposed a Si nanowire field-effect transistor (Si-NW Bio-FET) device chemically modified with specific antibodies for the electrical and label-free detection of exosomes. The Si-NW FETs were fabricated by standard microelectronic processes with 45 nm width nanowires and packaged in a polydimethylsiloxane (PDMS) microfluidic channel. The nanowires were further modified with the specific CD63 antibody to form a Si-NW Bio-FET. The use of the developed Si-NW Bio-FET for the electrical and label-free detection of exosomes was successfully demonstrated with a limit of detection (LOD) of 2159 particles/mL. In contrast to other technologies, in this study, Si-NW Bio-FET provides a unique strategy for directly quantifying and real-time detecting exosomes without labeling, indicating its potential as a tool for the early diagnosis of cancer.”
“a Schematic diagram of the Si-NW Bio-FET. b Schematic diagram of the Si-NW Bio-FET cross-section. c Schematic diagram of signal changes. d Simplified fabrication protocol for Si-NW Bio-FET. (I) The SOI wafer with a p-type (100) crystal face. (II) Thinning of the top silicon layer. (III) Deposition of SiO2/α-Si/Si3N4 layer. (IV) Pattern of α-Si; (V) Deposition of Si3N4. (VI) Formation of Si3N4 hard mask. (VII) Removal of α-Si; (VIII) SiO2 and top silicon RIE. (IX) Formation of Si-NW” Reproduced under Creative Commons Attribution 4.0 International License from Zhao, W., Hu, J., Liu, J. et al. Si nanowire Bio-FET for electrical and label-free detection of cancer cell-derived exosomes. Microsyst Nanoeng 8, 57 (2022).
Figures and the abstract are reproduced from Zhao, W., Hu, J., Liu, J. et al. Si nanowire Bio-FET for electrical and label-free detection of cancer cell-derived exosomes. Microsyst Nanoeng 8, 57 (2022). https://doi.org/10.1038/s41378-022-00387-x under Creative Commons Attribution 4.0 International License.
Read the original article: Si nanowire Bio-FET for electrical and label-free detection of cancer cell-derived exosome