General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors

Ning Gao, Wei Zhou, Xiaocheng Jiang, Guosong Hong, Tian Ming Fu, Charles M. Lieber

Research output: Contribution to journalArticlepeer-review

208 Scopus citations


Transistor-based nanoelectronic sensors are capable of label-free real-time chemical and biological detection with high sensitivity and spatial resolution, although the short Debye screening length in high ionic strength solutions has made difficult applications relevant to physiological conditions. Here, we describe a new and general strategy to overcome this challenge for field-effect transistor (FET) sensors that involves incorporating a porous and biomolecule permeable polymer layer on the FET sensor. This polymer layer increases the effective screening length in the region immediately adjacent to the device surface and thereby enables detection of biomolecules in high ionic strength solutions in real-time. Studies of silicon nanowire field-effect transistors with additional polyethylene glycol (PEG) modification show that prostate specific antigen (PSA) can be readily detected in solutions with phosphate buffer (PB) concentrations as high as 150 mM, while similar devices without PEG modification only exhibit detectable signals for concentrations ≤10 mM. Concentration-dependent measurements exhibited real-time detection of PSA with a sensitivity of at least 10 nM in 100 mM PB with linear response up to the highest (1000 nM) PSA concentrations tested. The current work represents an important step toward general application of transistor-based nanoelectronic detectors for biochemical sensing in physiological environments and is expected to open up exciting opportunities for in vitro and in vivo biological sensing relevant to basic biology research through medicine.

Original languageEnglish (US)
Pages (from-to)2143-2148
Number of pages6
JournalNano Letters
Issue number3
StatePublished - Mar 11 2015
Externally publishedYes

All Science Journal Classification (ASJC) codes

  • General Chemistry
  • Condensed Matter Physics
  • Mechanical Engineering
  • Bioengineering
  • General Materials Science


  • Debye length
  • Semiconductor nanowires
  • bioelectronics
  • field-effect-transistor
  • polyethylene glycol
  • polymer-modified


Dive into the research topics of 'General strategy for biodetection in high ionic strength solutions using transistor-based nanoelectronic sensors'. Together they form a unique fingerprint.

Cite this