The genome, which is an organism’s complete genetic blueprint, consists of a dynamic mixture of unique and repetitive DNA sequences that are continuously evolving, making the human genome a prime example of this complexity. Repetitive sequences emerge through mechanisms such as replication slippage, transpositions, and unequal recombination, whereas non-repetitive sequences evolve through point mutations, insertions and deletions, segmental duplication errors, and horizontal gene transfers. This review explores the evolution of polymeric nucleic acids, genome proliferation and homeostasis, and the various mechanisms that drive genomic diversity. It further highlights the occurrence and biological significance of DNA repeats across different domains of life. In addition, the review critically evaluates the impact of these sequences on genome instability, regulatory processes, and their involvement in human diseases. The concluding sections integrate current evidence on the contribution of repetitive elements to evolution, focusing on the interplay between genetic and epigenetic mechanisms that govern their fate, and emphasize how this knowledge is crucial for advancing genome function research and personalized medicine.

Infection with hepatitis B virus (HBV) is a global health problem, causing diseases such as acute and chronic hepatitis, liver cirrhosis, and hepatocellular carcinoma. Numerous studies in the literature have demonstrated hepatitis B surface antigen (HBsAg) as the first virological marker of HBV infection, and that serum HBsAg levels are reported to be an important criterion for the diagnosis and management of HBV infection. Therefore, the sensitive and selective detection of HBsAg is critical for the early diagnosis of hepatitis B and for the management of the diseases associated with HBV infection. Electrochemical immunosensors play an important role in the early diagnosis of infection with hepatitis B virus since they are rapid, easy-to-use, and reliable diagnostic tools with a possibility of on-site detection. Besides, they might have superior performance in terms of multiple analytical parameters compared to more commonly used alternatives in the clinic, including ELISA. Herein, we review the reported success and potential of electrochemical biosensors for the detection of HBsAg in the early diagnosis and monitoring of hepatitis B virus infection, and provide a brief overview for future studies, with the ultimate aim of directing more research focus into this topic.