Biocompatible functional hydrogels are ideal materials for future diagnostic sensors. Their responsiveness to external stimuli, often in the form of varying optical and mechanical properties, has greatly promoted the development in biosensing systems. In this thesis, I designed a hybrid hydrogel system using biocompatible triblock copolymers, also known as Pluronics, which have been functionalized with azide and azide-single-stranded (ss)DNA linkers. Here the azide group served as reaction agent to bind ssDNA covalently to the Pluronics’ chain ends. The Pluronics used are known as F108 and F127, both having the same block-size ratio but differing in molecular weight. In depth experimental characterisation and computational simulation for these systems are presented in this thesis.

First, I will present the experimental characterisation of the micellization and aggregation behaviour of azide and azide-ssDNA functionalized Pluronic F108, in dilute and semi-concentrated aqueous solutions; these results are also compared with their non-functionalized counterparts. I observed remarkable differences in the structural properties of those F108 samples, mainly due to the azide-functionalization which introduces non-specific hydrophobic interactions between the solvated PEO chain-ends of the Pluronics and thus promotes the formation of flower micelles. Next, I will discuss the structure of the various phases, presenting detailed Small-Angle X-Ray Scattering measurements. To understand the effect of the DNA on the phase behaviour of our systems, I will also present simulation data, which enabled us to explore the entire phase diagram for the plain and the ssDNA functionalized F108 in aqueous solution. In this simulation study, I also explored Pluronic F127 solutions, as these are used in many biological and bio-technological applications.

By controlling the interplay between these two species, a fine control over the rheological, temperature-dependent response of these systems were obtained. The biocompatibility and thermo-reversibility of these materials opens the possibility for a large number of applications related to biomedicine and drug delivery fields in which a fine control of mechanical properties is usually required.