Dendrimers in biosensors: Concept and applications

Abstract

The performance of biosensors, i.e. the sensitivity, specificity, linearity, reusability, chemical stability, and reproducibility is critically dependent on the biofunctionalization of the sensor platform. The type (s) of linkers used for the immobilization of the capture probes and the exact immobilization protocol play a vital role in the overall performance of sensors. A variety of linker molecules have been used to biofunctionalize technologically important substrates (glass, gold, mica etc.). Amongst the different linkers, researchers have paid more attention to two dimensional architectures, e.g. silanes, polyaniline (PANI), alkanethiols, poly-L-lysine (PLL), etc. Despite extensive research and a large number of reports, researchers still face problems related to limited loading efficiency, limited accessibility of the probes, poor control over uniform spacing among the probes and a loss of functionality due to irregular orientation of the probes, all of which cause variability in the responses. Three dimensional gel based matrices have proved to be a better choice, except for the fact that the leaching of entrapped probe molecules has limited their use in developing sensor platforms. Taking into account the limitations of the two dimensional linker arrays and three dimensional gel matrices, supramolecular dendritic architectures have shown immense potential in designing and developing the sensor platforms. Dendrimers are well-defined, monodispersed, globular macromolecules constructed around a core unit. Different properties of dendrimers, i.e. their structural uniformity, globular shape, monodispersity, the existence of dendritic crevices, high functional group density, hydrophilicity, versatility to design

Oligomeric Thiosemicarbazones as Novel Immobilization Matrix in Biosensing Applications

“…The low Michaelis-Menten constant reveals a high affinity of enzyme to its substrate. As can be seen from the Table 1, the K m is much lower than those reported for Copolymers of vinyl alcohol with thiophene side groups and pyrrole/GOx, 47 Poly(2-Dodecyl-4,7-di(thiophen-2-yl)-2H-benzo[d] [1,2,3]triazole)/GOx, 31 Poly (N-(4-(3-thienylmethylene)-oxycarboyl phenyl) maleimideco-pyrrole/GOx. 41 The integration of biosensors to FIA mode has a large variety of applications (37,38).…”

“…The isolation of enzymes from their native environment leads to a decrease in their operational stability and sensitivity (1). Immobilizing enzymes efficiently on electrode surface is one of the most important steps in biosensor applications.…”

Synthesis and NMR characterization of dendrimers based on 2, 2-bis-(hydroxymethyl)-propanoic acid (bis-HMPA) containing peripheral amino acid residues for gene transfection

“…Branched polyethylenimine (PEI-b, 25 kDa) and all the reagents and solvents were purchased from Aldrich or Merck. N-BOC-amino acids 16a-f were prepared according to literature procedure and synthetic and analytical data are reported and available in Supporting Information (pages [3][4][5]. The solvents were dried and distilled according to standard procedures.…”

The peculiarities of the photoorientation processes in azobenzene-containing liquid crystalline homo- and co-dendrimers

“…One of the most promising substances designed in order to obtain smart materials are dendrimers, high-molecular mass compounds having superbranched molecular structure predetermining their unique physico-chemical properties [1]. Introduction of photochromic moieties into the central core, dendrimer matrix or as terminal groups enables to create a huge variety of new photoresponsive materials which can be used for regulated drug delivery, development of new types of biosensors, optoelectronics, etc [1][2][3][4][5][6][7][8].…”