Optimized Light-Directed Synthesis of Aptamer Microarrays

Author(s)
Nicole L. W. Franssen-van Hal, Pepijn van der Putte, Klaus Hellmuth, Stefan Matysiak, Nicole Kretschy, Mark Manuel Somoza
Abstract

Aptamer microarrays are a promising high-throughput method for ultrasensitive detection of multiple analytes, but although much is known about the optimal synthesis of oligonucleotide microarrays used in hybridization-based genomics applications, the bioaffinity interactions between aptamers and their targets is qualitatively different and requires significant changes to synthesis parameters. Focusing on streptavidin-binding DNA aptamers, we employed light-directed in situ synthesis of microarrays to analyze the effects of sequence fidelity, linker length, surface probe density, and substrate functionalization on detection sensitivity. Direct comparison with oligonucleotide hybridization experiments indicates that aptamer microarrays are significantly more sensitive to sequence fidelity and substrate functionalization and have different optimal linker length and surface probe density requirements. Whereas microarray hybridization probes generate maximum signal with multiple deletions, aptamer sequences with the same deletion rate result in a 3-fold binding signal reduction compared with the same sequences synthesized for maximized sequence fidelity. The highest hybridization signal was obtained with dT 5mer linkers, and the highest aptamer signal was obtained with dT 11mers, with shorter aptamer linkers significantly reducing the binding signal. The probe hybridization signal was found to be more sensitive to molecular crowding, whereas the aptamer probe signal does not appear to be constrained within the density of functional surface groups commonly used to synthesize microarrays.

Organisation(s)
Department of Inorganic Chemistry
External organisation(s)
FlexGen
Journal
Analytical Chemistry
Volume
85
Pages
5950-5957
No. of pages
8
ISSN
0003-2700
DOI
https://doi.org/10.1021/ac400746j
Publication date
2013
Peer reviewed
Yes
Austrian Fields of Science 2012
104002 Analytical chemistry
Portal url
https://ucrisportal.univie.ac.at/en/publications/68b7e254-fb7a-4995-bca8-502e43624bcf