Hydrogels are three-dimensional networks of polymers that swell in contact with water. They acquire their water-holding capacity by hydrophilic functional groups on the polymer chain. Fully swollen hydrogels are viscoelastic, soft, rubbery and biocompatible. They are also mostly degradable, depending on the crosslinker used. Fingerprinting is most performed with brushes, gauzes, adhesive tapes and although these methods are useful, there are several limitations including cost disadvantage, complexity of operation, low resolution, DNA contamination, destruction of fingerprints and toxicity of some of the substances used. Most methods are also not suitable for the storage of latent fingerprint information. Modern approaches therefore focus on hydrogel materials due to their high sensitivity, selectivity, and flexibility. When designing hydrogels for a specific purpose, the degree of swelling is a key parameter as it affects the diffusion, mechanical, optical, and surface properties of the hydrogel. The mechanical properties of stiffness, which is related to the elasticity of the hydrogel, and diffusivity are also important. The influence on the properties of hydrogels can be achieved by varying the polymer concentration, the crosslinking agent and the incorporation of specific ions and molecules. In my thesis I reviewed recent research in the design of hydrogels with desired properties that are potentially useful in forensics. In doing so, I focused on the design of the mechanical properties of hydrogels, the control of amino acid release and the possibility of adsorbing DNA onto the surface of hydrogels.
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