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Biomimetic strategies for sensing biological species.

Hussain M, Wackerlig J, Lieberzeit PA - Biosensors (Basel) (2013)

Bottom Line: A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them.Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors.It mainly focuses on the literature published since 2005.

View Article: PubMed Central - PubMed

Affiliation: Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, A-1090, Vienna, Austria; E-Mails: munawar_arif@hotmail.com (M.H.); judith.maehner@univie.ac.at (J.W.).

ABSTRACT
The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005.

No MeSH data available.


Principle of the method. Formation of biomolecule-templated thiol self-assembled monolayers (SAM), and the subsequent removal of the template molecules to create recognition sites in the SAM matrix. Reprinted with permission from [19], © 2010 Elsevier.
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biosensors-03-00089-f003: Principle of the method. Formation of biomolecule-templated thiol self-assembled monolayers (SAM), and the subsequent removal of the template molecules to create recognition sites in the SAM matrix. Reprinted with permission from [19], © 2010 Elsevier.

Mentions: A different approach suggests synthesizing MIP membranes have been reported based on self-assembly to more closely mimic natural functionality, a huge amount of which actually happens in (cell) membranes. For example, Zhao et al. [17] used such an approach to generate polyacrylamide-based MIPs for lysozyme that reach adsorption equilibrium 16 times faster compared to previously prepared lysozyme MIP [18]. However, their strategy, in a way, can be regarded as rather “classical”, as they coated a thin film onto the substrate and covered it with Mylar, followed by polymerization at room temperature for 24 h under mild reaction conditions, initiated without heating and ultraviolet radiation to prevent denaturing of lysozyme. In this manner, they could make sure that the template does not change its conformation during polymerization. Wang et al. [19] further developed the process and achieved detection of cancer biomarkers and other proteins by synthesizing surface-imprinted, self-assembled monolayers. For that purpose, the authors co-adsorbed hydroxyl-terminated alkane thiols and template biomolecules on gold-coated silicon chips, making use of the covalent bond between the thiol molecules and the gold surface leading to self-assembled monolayers. The biomolecules are removed from the surface which ultimately creates “footprint” cavities in the monolayer matrix. In Figure 3, the principle of the described method is demonstrated. Re-inclusion of biomolecules into the SAM on the sensor chip can be detected potentiometrically. Generally speaking, this leads to very rapid sensor responses and comparably high sensitivities, because electroanalytical techniques that require direct contact between the analyte and the template become realistic. The group of Gauglitz [20] have developed a biomimetic sensor that allows quantification of autoantibodies related to the antiphospholipid syndrome (APS). The substantial challenge in this case is to overcome problems in establishing a reliable recognition element for assessing the target marker against β2-glycoprotein-I (β2GP-I): β2GP-I binds to negatively charged membranes and exposes the correct epitopes only in this bound state. Otherwise, the binding sites are hidden within the protein, which makes immunoassays with the whole protein useless. To provide an environment comparable to the physiological conditions in the human body, the authors co-immobilized a multilayer assembly of covalently attached polymeric DCPEG/PEG (lipid anchor) and a liposome membrane on the transducer. Quantification of anti-β2GP-I antibodies and calibration of the sensor chip in buffer was done using reflectometric interference spectroscopy. This strategy can be extended to distinguish between healthy and ill individuals within routine clinical diagnostics. Furthermore, it is an impressive example for the fact that in bioanalysis not only the target analyte plays a role, but also its environment. In this way, the sensor surface mimics not “only” an antibody or binding site, but also the membrane structure necessary to ensure biological activity.


Biomimetic strategies for sensing biological species.

Hussain M, Wackerlig J, Lieberzeit PA - Biosensors (Basel) (2013)

Principle of the method. Formation of biomolecule-templated thiol self-assembled monolayers (SAM), and the subsequent removal of the template molecules to create recognition sites in the SAM matrix. Reprinted with permission from [19], © 2010 Elsevier.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4263596&req=5

biosensors-03-00089-f003: Principle of the method. Formation of biomolecule-templated thiol self-assembled monolayers (SAM), and the subsequent removal of the template molecules to create recognition sites in the SAM matrix. Reprinted with permission from [19], © 2010 Elsevier.
Mentions: A different approach suggests synthesizing MIP membranes have been reported based on self-assembly to more closely mimic natural functionality, a huge amount of which actually happens in (cell) membranes. For example, Zhao et al. [17] used such an approach to generate polyacrylamide-based MIPs for lysozyme that reach adsorption equilibrium 16 times faster compared to previously prepared lysozyme MIP [18]. However, their strategy, in a way, can be regarded as rather “classical”, as they coated a thin film onto the substrate and covered it with Mylar, followed by polymerization at room temperature for 24 h under mild reaction conditions, initiated without heating and ultraviolet radiation to prevent denaturing of lysozyme. In this manner, they could make sure that the template does not change its conformation during polymerization. Wang et al. [19] further developed the process and achieved detection of cancer biomarkers and other proteins by synthesizing surface-imprinted, self-assembled monolayers. For that purpose, the authors co-adsorbed hydroxyl-terminated alkane thiols and template biomolecules on gold-coated silicon chips, making use of the covalent bond between the thiol molecules and the gold surface leading to self-assembled monolayers. The biomolecules are removed from the surface which ultimately creates “footprint” cavities in the monolayer matrix. In Figure 3, the principle of the described method is demonstrated. Re-inclusion of biomolecules into the SAM on the sensor chip can be detected potentiometrically. Generally speaking, this leads to very rapid sensor responses and comparably high sensitivities, because electroanalytical techniques that require direct contact between the analyte and the template become realistic. The group of Gauglitz [20] have developed a biomimetic sensor that allows quantification of autoantibodies related to the antiphospholipid syndrome (APS). The substantial challenge in this case is to overcome problems in establishing a reliable recognition element for assessing the target marker against β2-glycoprotein-I (β2GP-I): β2GP-I binds to negatively charged membranes and exposes the correct epitopes only in this bound state. Otherwise, the binding sites are hidden within the protein, which makes immunoassays with the whole protein useless. To provide an environment comparable to the physiological conditions in the human body, the authors co-immobilized a multilayer assembly of covalently attached polymeric DCPEG/PEG (lipid anchor) and a liposome membrane on the transducer. Quantification of anti-β2GP-I antibodies and calibration of the sensor chip in buffer was done using reflectometric interference spectroscopy. This strategy can be extended to distinguish between healthy and ill individuals within routine clinical diagnostics. Furthermore, it is an impressive example for the fact that in bioanalysis not only the target analyte plays a role, but also its environment. In this way, the sensor surface mimics not “only” an antibody or binding site, but also the membrane structure necessary to ensure biological activity.

Bottom Line: A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them.Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors.It mainly focuses on the literature published since 2005.

View Article: PubMed Central - PubMed

Affiliation: Department of Analytical Chemistry, University of Vienna, Waehringer Strasse 38, A-1090, Vienna, Austria; E-Mails: munawar_arif@hotmail.com (M.H.); judith.maehner@univie.ac.at (J.W.).

ABSTRACT
The starting point of modern biosensing was the application of actual biological species for recognition. Increasing understanding of the principles underlying such recognition (and biofunctionality in general), however, has triggered a dynamic field in chemistry and materials sciences that aims at joining the best of two worlds by combining concepts derived from nature with the processability of manmade materials, e.g., sensitivity and ruggedness. This review covers different biomimetic strategies leading to highly selective (bio)chemical sensors: the first section covers molecularly imprinted polymers (MIP) that attempt to generate a fully artificial, macromolecular mold of a species in order to detect it selectively. A different strategy comprises of devising polymer coatings to change the biocompatibility of surfaces that can also be used to immobilized natural receptors/ligands and thus stabilize them. Rationally speaking, this leads to self-assembled monolayers closely resembling cell membranes, sometimes also including bioreceptors. Finally, this review will highlight some approaches to generate artificial analogs of natural recognition materials and biomimetic approaches in nanotechnology. It mainly focuses on the literature published since 2005.

No MeSH data available.