Optimizing surface modification of silicon nanowire field-effect transistors by polyethylene glycol for MicroRNA detection

Cao An Vu, Hsin Ying Lai, Chia Yu Chang, Hardy Wai Hong Chan, Wen Yih Chen

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


MicroRNA (miRNA) sensing plays an essential role in the diagnosis of several diseases, especially cancers, for appropriate intervention and treatment. However, quantifying miRNA demands highly sensitive and selective assays which can distinguish analogous sequences with low abundance in bio-samples and determine wide range of concentrations. In this report, we present a novel technique satisfying all those requirements by modifying silicon nanowire field-effect transistors (SiNWFETs) with 2-component mixed self-assembled monolayers (mSAMs) of polyethylene glycol (PEG) at different ratios (silane-PEG-NH2:silane-PEG-OH = 1:1, 1:3, and 1:5) and glutaraldehyde to immobilize DNA probes for miRNA-21 detection, a biomarker in several types of cancers. Empirical results reveal that all the fabricated PEG-SiNWFET DNA biosensors could quantify miRNA-21 within 1 fM – 10 pM. Especially, the ones modified with silane-PEG-NH2:silane-PEG-OH = 1:3 exhibited an outstanding performance to recognize miRNA-21 at an ultra-low concentration of 10 aM in the dynamic range up to 6 orders of magnitude (10 aM – 10 pM). This approach is more convenient, analytical competitive, and cost-effective in comparison with currently used methods for nucleic acid testing because of label- and amplification-free characteristics. It is therefore not only feasible for miRNA detection by SiNWFET-based biosensors but also potential for clinical applications of disease diagnosis with oligonucleotide biomarkers.

Original languageEnglish
Article number112142
JournalColloids and Surfaces B: Biointerfaces
StatePublished - Jan 2022


  • Cancer Biomarker
  • Polyethylene Glycol
  • Silicon Nanowire Field-Effect Transistor Biosensor
  • miRNA-21
  • mixed Self-Assembled Monolayer


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