Electrochemical lectin based biosensors as a label-free tool in glycomics

Abstract

Glycans and other saccharide moieties attached to proteins and lipids, or present on the surface of a cell, are actively involved in numerous physiological or pathological processes. Their structural flexibility (that is based on the formation of various kinds of linkages between saccharides) is making glycans superb "identity cards". In fact, glycans can form more "words" or "codes" (i.e., unique sequences) from the same number of "letters" (building blocks) than DNA or proteins. Glycans are physicochemically similar and it is not a trivial task to identify their sequence, or - even more challenging - to link a given glycan to a particular physiological or pathological process. Lectins can recognise differences in glycan compositions even in their bound state and therefore are most useful tools in the task to decipher the "glycocode". Thus, lectin-based biosensors working in a label-free mode can effectively complement the current weaponry of analytical tools in glycomics. This review gives an introduction into the area of glycomics and then focuses on the design, analytical performance, and practical utility of lectin-based electrochemical label-free biosensors for the detection of isolated glycoproteins or intact cells.

Glycoprofiling as a novel tool in serological assays of systemic sclerosis: A comparative study with three bioanalytical methods

“…The same is true for impedimetric lectin biosensors, which have not been applied in analysis of this type of human samples [19,26]. ELLA has not been applied in glycoprofiling of SSc sera and thus glycoprofiling of SSc sera is a completely novel approach for analysis of this type of samples with a potential to be applied in diagnostics of this disease after further development in the future.…”

“…It is well-known that presence of labels can negatively affect binding [24,25] and thus label-free methods of analysis are preferential option for diagnostic purposes. One of the most sensitive biosensing detection platform is electrochemical impedance spectroscopy (EIS), offering robust, extremely sensitive method for monitoring of biorecognition events in a label-free mode of operation [19,[26][27][28]. This method is based on the application of small amplitude alternating voltage (perturbation) to the interfacial layer on the electrode, measuring the double layer capacitance (C DL ) and charge transfer resistance (R CT ), respectively [29][30][31].…”

Electrochemical sensing of concanavalin A and ovalbumin interaction in solution

“…ConA is a metalloprotein, requiring the presence of metal ions for proper binding function; each subunit of ConA contains one manganese (Mn 2+ ) and one calcium (Ca 2+ ) ion [16]. These biological properties of ConA have led to its utilization in various biotechnological applications [17,18].…”

Perspectives in Glycomics and Lectin Engineering

“…EIS is extensively used as a non-destructive technique for reliable analysis of surface conditions and allows complex biorecognition events to be probed in a simple, sensitive and label-free manner and is being increasingly popular to develop electrochemical lectin-based biosensors for glycan determination (9,30). In our recent work we focused on the development of ultrasensitive impedimetric lectin biosensors with detection limits down to a single-molecule level based on controlled architecture at the nanoscale (59)(60)(61).…”

“…Glycan mediated recognition plays an important role in many different cell´s processes such as fertilisation, immune response, differentiation of cells, cellmatrix interaction, cell-cell adhesion etc. (9,10). Glycans present on the surface of cells are naturally involved in pathological processes including viral and bacterial infections, in neurological disorder and in tumour growth and metastasis (3,(11)(12)(13)(14)(15)(16).…”