The physical–chemical properties of the surface of DNA microarrays and biosensors play a fundamental role in their performance, affecting the signal’s amplitude and the strength and kinetics of binding. We studied how the interaction parameters vary for hybridization of complementary 23-mer DNA, when the probe strands are immobilized on different copolymers, which coat the surface of an optical, label-free biosensor. Copolymers of N, N-dimethylacrylamide bringing either a different type or density of sites for covalent immobilization of DNA probes, or different backbone charges, were used to functionalize the surface of a Reflective Phantom Interface multispot biosensor made of a glass prism with a silicon dioxide antireflective layer. By analyzing the kinetic hybridization curves at different probe surface densities and target concentrations in solution, we found that all the tested coatings displayed a common association kinetics of about 9 × 104 M−1·s−1 at small probe density, decreasing by one order of magnitude close to the surface saturation of probes. In contrast, both the yield of hybridization and the dissociation kinetics, and hence the equilibrium constant, depend on the type of copolymer coating. Nearly doubled signal amplitudes, although equilibrium dissociation constant was as large as 4 nM, were obtained by immobilizing the probe via click chemistry, whereas amine-based immobilization combined with passivation with diamine carrying positive charges granted much slower dissociation kinetics, yielding an equilibrium dissociation constant as low as 0.5 nM. These results offer quantitative criteria for an optimal selection of surface copolymer coatings, depending on the application.

Copolymer coatings for dna biosensors: Effect of charges and immobilization chemistries on yield, strength and kinetics of hybridization / L. Vanjur, T. Carzaniga, L. Casiraghi, G. Zanchetta, F. Damin, L. Sola, M. Chiari, M. Buscaglia. - In: POLYMERS. - ISSN 2073-4360. - 13:22(2021), pp. 3897.1-3897.13. [10.3390/polym13223897]

Copolymer coatings for dna biosensors: Effect of charges and immobilization chemistries on yield, strength and kinetics of hybridization

Vanjur L.;Carzaniga T.;Casiraghi L.;Zanchetta G.;Buscaglia M.
2021

Abstract

The physical–chemical properties of the surface of DNA microarrays and biosensors play a fundamental role in their performance, affecting the signal’s amplitude and the strength and kinetics of binding. We studied how the interaction parameters vary for hybridization of complementary 23-mer DNA, when the probe strands are immobilized on different copolymers, which coat the surface of an optical, label-free biosensor. Copolymers of N, N-dimethylacrylamide bringing either a different type or density of sites for covalent immobilization of DNA probes, or different backbone charges, were used to functionalize the surface of a Reflective Phantom Interface multispot biosensor made of a glass prism with a silicon dioxide antireflective layer. By analyzing the kinetic hybridization curves at different probe surface densities and target concentrations in solution, we found that all the tested coatings displayed a common association kinetics of about 9 × 104 M−1·s−1 at small probe density, decreasing by one order of magnitude close to the surface saturation of probes. In contrast, both the yield of hybridization and the dissociation kinetics, and hence the equilibrium constant, depend on the type of copolymer coating. Nearly doubled signal amplitudes, although equilibrium dissociation constant was as large as 4 nM, were obtained by immobilizing the probe via click chemistry, whereas amine-based immobilization combined with passivation with diamine carrying positive charges granted much slower dissociation kinetics, yielding an equilibrium dissociation constant as low as 0.5 nM. These results offer quantitative criteria for an optimal selection of surface copolymer coatings, depending on the application.
Copolymers; DNA hybridization; DNA hybridization kinetics; Label-free detection
Settore FIS/07 - Fisica Applicata(Beni Culturali, Ambientali, Biol.e Medicin)
RL_DG-UNI17MLOCA_01 - Piattaforma per l’identificazione di target di rilevanza farmacologica per il trattamento di patologie del sistema nervoso e oncologiche ad elevato bisogno di cura (NeOn) - LOCATI, MASSIMO - RL_DG-UNI - Bandi DG Università, ricerca e open innovation - 2017
PRIN201718TBELL_01 - SOFT ADAPTIVE NETWORKS - BELLINI, TOMMASO GIOVANNI - PRIN2017 - PRIN bando 2017 - 2018
POLYMERS
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Utilizza questo identificativo per citare o creare un link a questo documento: http://hdl.handle.net/2434/897963
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