DNA multilayer films are promising candidates for a plethora of applications, including sensing, diagnostics, and drug/gene delivery. Fabricated solely from DNA, the use of salt in formingDNAmultilayers is crucial in promoting and maintaining hybridization of complementary base pairs by minimizing the repulsive forces between the oligonucleotides and preventing disassembly of the layers once formed. Herein, we examine the role of salt on the assembly ofDNAfilms assembled from oligonucleotides composed of two homopolymeric diblocks (polyAnGn and polyTnCn) in salt concentrations ranging from 0.1 to 2 M. Using quartz crystal microgravimetry (QCM) and flow cytometry, we show that films assembled at high salt concentrations (2 M salt) exhibit a different morphology and are denser than those assembled from lower (1Msalt) salt solutions. Formation of the T 3 A*T triplex in solution and within theDNAfilm was also studied using circular dichroism (CD) and QCM, respectively. DNA films assembled using oligonucleotides of various lengths (20- to 60-mer) at high salt concentration (2Msalt) showed no significant influence on the film growth. This work shows that salt plays an important role in the assembly and final morphology ofDNAmultilayer films, hence enabling films with different properties to be tailored.
Lee, L., Cavalieri, F., Johnston, A., Caruso, F. (2010). Influence of Salt Concentration on the Assembly of DNA Multilayer Films. LANGMUIR, 26(5), 3415-3422 [10.1021/la9032145].
Influence of Salt Concentration on the Assembly of DNA Multilayer Films
CAVALIERI, FRANCESCA;
2010-01-01
Abstract
DNA multilayer films are promising candidates for a plethora of applications, including sensing, diagnostics, and drug/gene delivery. Fabricated solely from DNA, the use of salt in formingDNAmultilayers is crucial in promoting and maintaining hybridization of complementary base pairs by minimizing the repulsive forces between the oligonucleotides and preventing disassembly of the layers once formed. Herein, we examine the role of salt on the assembly ofDNAfilms assembled from oligonucleotides composed of two homopolymeric diblocks (polyAnGn and polyTnCn) in salt concentrations ranging from 0.1 to 2 M. Using quartz crystal microgravimetry (QCM) and flow cytometry, we show that films assembled at high salt concentrations (2 M salt) exhibit a different morphology and are denser than those assembled from lower (1Msalt) salt solutions. Formation of the T 3 A*T triplex in solution and within theDNAfilm was also studied using circular dichroism (CD) and QCM, respectively. DNA films assembled using oligonucleotides of various lengths (20- to 60-mer) at high salt concentration (2Msalt) showed no significant influence on the film growth. This work shows that salt plays an important role in the assembly and final morphology ofDNAmultilayer films, hence enabling films with different properties to be tailored.I documenti in IRIS sono protetti da copyright e tutti i diritti sono riservati, salvo diversa indicazione.
