Smart hydrogels, which combine hydrogel properties such as biocompatibility, high drug loading capacity, and injectability while being responsive to external stimuli, are a subclass of smart materials. Smart hydrogels respond to effects that are not harmful to the human body, such as temperature, pH, light, and biomolecules. Furthermore, some smart hydrogels possess dual-responsive properties or can be multifunctional, exhibiting both adhesive and responsive behavior to external stimuli. Smart hydrogels have made groundbreaking advances in the field of biomedical. They have been improved through structural modifications and by gaining the ability to be multi-responsive. Controlling drug release and biofilm disruption by using these smart hydrogels is one of the efficient strategies to reduce antimicrobial resistance and the number of deaths caused by microbial diseases. In this review, the preparation of smart hydrogels, their various types and applications in the treatment of microbial diseases were investigated.

Dye sensitized solar cells (DSSCs) are photovoltaic devices that produce electricity from the photon energy of sunlight using dyes. Dyes used DSSCs should have a broad absorption spectrum at the UV-Vis region and should be strongly bound to the photoanode surface. Dyes are used in DSSCs can be classified into three types: metal complex dyes, metal-free organic dyes and natural dyes. For metal complex dyes, ruthenium is usually used as metal centers. While most Ru complex dyes have high efficiency, Ru is a rare metal. To decrease the cost of Ru complex dyes, transition metals are widely investigated. In this work, diphenylcarbazone and tartrazine with different metal complexes were synthesized and investigated for their suitability for DSSCs. UV-Vis was used for the characterization of dyes and linear sweep voltammetry and electrochemical impedance spectroscopy were used to investigate the performance of DSSCs.