Electrochemical analysis of nucleic acids, proteins and polysaccharides in biomedicine

Abstract

Electrochemical analysis of nucleic acids, proteins and polysaccharides represents an interesting, although not widely spread alternative to current methods based predominantly on optical detection because it offers a relatively inexpensive, fast and instrumentally simple detection of parallel samples on miniaturized chips, ideal for personalized medicine of the 21st century. Nucleic acid electrochemistry enables, for example, detection of specific DNA sequences (for determination of genes or presence of bacteria and viruses, etc.), DNA damage analysis and interaction with other molecules, DNA methylation or detection of microRNAs as potential cancer bio-markers. In the electrochemistry of proteins, great emphasis is put on construction of immunosensors for capturing specific proteins (antigens) using antibodies, suitable for diagnostics. From a bio-physical point of view, intrinsic electrocatalytic signal of proteins sensitive to conformational changes could be useful in discrimination of mutant proteins (e. g. p53), native and aggregated forms (α-synuclein in Parkinsons disease) or for studies of protein interactions with low molecular weight ligands and DNA. Due to an increased interest of scientists in glycoproteins, new electrochemical papers emerged aiming at detection of oligosaccharides and polysaccharides (i.e. glycans, when part of the protein). These assays employ for instance electroactive labels specific for saccharides or lectin bio-sensors using lectins which strongly bind glycans. Electrochemical analysis thus appears as an interesting tool in current genomics, proteomics and glycomics, as well as for cancer diagnostics.