# Special Issue \"World of Biosensing\"
###### Abstract  
The broad definition of the term biosensing relates to practically all processes of molecular recognition. Owing to the unique selectivity of such recognition, molecular interactions between DNA-DNA, DNA-RNA, DNA/RNA-regulatory proteins, enzymes-substrates (as well as co-enzymes, inhibitors, effectors), hormones-receptors, antigens-antibodies, etc. are fundamental to life [1]. Undoubtedly, unique evolutionary-derived molecular recognition processes have been used for analytical purposes, namely for construction of biosensors.  
A commonly cited definition of a \"biosensing\" only focuses on analytical aspects of the field. (Bio)sensors are devices which are based on selective (bio)recognition-enabling sensitive monitoring and measurement of target analytes or processes by converting biological or chemical responses into corresponding signals [2]. In the last decades, (bio)sensors have caused revolutionary changes in analytical chemistry, replacing the complex and tedious traditional methods of analysis with fast, selective, and accurate measurements of responses to specific analytes and processes. The main applications of (bio)sensors are in medicine (clinical and patient care diagnostics, control for therapy); pharmacy (drug development and monitoring); agriculture; water and environmental monitoring; biofense and military security; and the food industry (quality and safety of products and beverages) [3; 4; 5].  
The majority of biosensors are based on biochemical recognition elements, including enzymes, antibodies, antigens, nucleic acids and other natural biomolecules or their biomimetics [6]. At the same time, cell-based biosensors are also of essential interest due to their great potential for their application in the areas of environmental pollution detection and in biomedical diagnostics [7]. In contrast to molecular-based devices, biosensors containing native or recombinant living cells, pieces of tissue, organelles, biomembranes, liposomes or receptors, have some important advantages, including easy isolation and a broad specificity to the studied analytes. Both the possibility of improving biosensor signaling gene engineering and the availability of effective methods for cell immobilization are the valuable properties of cell-based biosensors [6; 7].  
The global market of (bio)sensors was estimated to be worth USD 25.1 billion in 2021, and is expected to reach USD 38 billion by 2028 [8]. Improvements in the development of biosensors will significantly amplify their commercial production in the forecast period. Devices that detect analytes using optical and electrochemical transducers (including piezoelectrical) have progressed significantly. The most essential advantages of biosensors are excellent chemical selectivity, high sensitivity and a possibility of miniaturization. The drawbacks of biosensors are their limited stability and complicated procedure for the preparation of the biologically active material.  
Combining bio- and nanotechnologies will enhance the production of perfect materials for biosensors. Such materials are necessary for the fabrication of traditional devices with improved analytical characteristics, as well as the design and generation of new high-techbiosensors, including piezoelectric, mass-based and nanomechanical sensors amongst other types [9; 10].