ИСТИНА

One of the most impressive current trends in modern chemistry is the design of advanced functional materials for biology and medicine. In the most of cases, gentle control over desired functional properties of artificially fabricated nanomaterials is required to apply spectroscopic analytical tools for noninvasive, highly effective and robust diagnostics of various complicated objects, for example, for comprehensive studies of biomolecules and markers of various. Nowadays, surface-enhanced Raman spectroscopy (SERS) becomes a promising universal low-cost and real-time tool in biomedical applications, medical screening or forensic analysis allowing the detection of different molecules below nanomolar concentrations. The main advantages of SERS include high sensitivity, specific determination of molecules by characteristic spectra, simple sample preparation, unique possibility to enhance Raman scattering of trace amounts of analytes up to 1014 times and the chance of non-destructive analysis of living systems. Silver nanoparticles and nanostructures are a common choice for SERS measurements due to a tunable plasmon resonance, high stability and facile fabrication methods. However, a proper design of silver-based nanomaterials for highly sensitive SERS applications still remains a challenge. The report is focused on the searching and development of new, original, processing and cost effective preparation methods to fabricate various silver nanomaterials and has the goal to practically implement the new experimental findings into the prospective area of innovative biomedical diagnostics using SERS. In particular, a class of novel processing methods is systematically developed in this work based on deep understanding of silver chemistry and aqueous diamminesilver hydroxide transformnation under various conditions as a flexible and universal precursor. Also, for the first time, an original technique of non-invasive study of cells and cellular structures using SERS substartes is proposed and successfully demonstrated in the case of living erythrocytes and functional mytochondria. The main purpose of the current work is the development of new active elements of ultrasensitive optical biosensors based on AgNPs for detection of trace amounts of analytes and pollutants and for study of structural and conformational changes of biomolecules by SERS. A potential of further practical applications of the nanomaterials for personal medicine and new biomedical diagnostics is discussed. This work is supported by Russian Science Foundation (grant 14-13-00871).