High density diffusion-free nanowell arrays

Bharath R. Takulapalli, Ji Qiu, Dewey Magee, Peter Kahn, Al Brunner, Kristi Barker, Steven Means, Shane Miersch, Xiaofang Bian, Alex Mendoza, Fernanda Festa, Karan Syal, Jin Park, Joshua LaBaer, Peter Wiktor

Research output: Contribution to journalArticlepeer-review

36 Scopus citations


Proteomics aspires to elucidate the functions of all proteins. Protein microarrays provide an important step by enabling high-throughput studies of displayed proteins. However, many functional assays of proteins include untethered intermediates or products, which could frustrate the use of planar arrays at very high densities because of diffusion to neighboring features. The nucleic acid programmable protein array (NAPPA) is a robust in situ synthesis method for producing functional proteins just-in-time, which includes steps with diffusible intermediates. We determined that diffusion of expressed proteins led to cross-binding at neighboring spots at very high densities with reduced interspot spacing. To address this limitation, we have developed an innovative platform using photolithographically etched discrete silicon nanowells and used NAPPA as a test case. This arrested protein diffusion and cross-binding. We present confined high density protein expression and display, as well as functional protein-protein interactions, in 8000 nanowell arrays. This is the highest density of individual proteins in nanovessels demonstrated on a single slide. We further present proof of principle results on ultrahigh density protein arrays capable of up to 24000 nanowells on a single slide.

Original languageEnglish (US)
Pages (from-to)4382-4391
Number of pages10
JournalJournal of Proteome Research
Issue number8
StatePublished - Aug 3 2012


  • diffusion-free
  • functional proteins
  • high density arrays
  • in situ synthesis
  • nanowells
  • piezoelectric printing
  • protein microarrays
  • proteome on chip
  • silicon microwells

ASJC Scopus subject areas

  • Biochemistry
  • General Chemistry


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