Polybetaine nanobrushes are widely used as inert platforms for label-free biosensing due to their resistance to nonspecific interactions. Despite being considered cationic or electrically neutral, polybetaines can exhibit a negative zeta potential (ZP) at pHs above their isoelectric point (pI). To clarify whether negative zeta potential effectively contributes to surface interactions, we examined three types of nanobrushes deposited on a planar gold substrate: two polybetaines: poly(carboxybetaine methacrylamide) (pCBMAA) and poly(sulfobetaine methacrylamide) (pSBMAA) and hydrophilic poly[N-(2-hydroxypropyl) methacrylamide] (pHPMAA), which carries no ionic group. All three brushes exhibit a well-defined pI and negative surface ZP at pHs above their pI. The pH dependence of the interactions of these brushes with anionic dextran sulfate (DS) and cationic poly[(N-trimethylammonium)ethyl methacrylate] (PTMAEMA) was monitored by infrared reflection spectroscopies (infrared reflection absorption spectroscopy (IRRAS), grazing angle attenuated total reflectance (GAATR)). DS adsorbs to pCBMAA strongly and only weakly to pSBMAA at pHs below their pI but can adsorb slightly to both polybetaines even at pHs above their pI. This is due to the displacement of their carboxylate or sulfo groups from the interaction with the quaternary ammonium cation by the DS sulfate groups. However, DS does not adsorb to pHPMAA at any pH, and PTMAEMA does not adsorb to any of the brushes, regardless of pH. These findings highlight that zeta potential determinations alone may not be sufficient to predict electrostatic interactions as the apparent negative charge does not necessarily translate into a functional surface charge influencing macromolecular interactions.

• Publikační typ
• časopisecké články MeSH

Continuous in vivo monitoring of small molecule biomarkers requires biosensors with reversibility, sensitivity in physiologically relevant ranges, and biological stability. Leveraging the real-time, label-free detection capability of surface plasmon resonance (SPR) technology, a molecularly responsive hydrogel film is introduced to enhance small molecule sensitivity. This advanced biosensing platform utilizes split-aptamer-cross-linked hydrogels (aptagels) engineered using 8-arm poly(ethylene glycol) macromers, capable of directly and reversibly detecting vancomycin. Investigation through SPR and optical waveguide mode, along with quartz crystal microbalance with dissipation (QCM-D) monitoring, reveals that the reversible formation of analyte-induced ternary molecular complexes leads to aptagel contraction and significant refractive index changes. Optimization of aptamer cross-link distribution and complementarity of split-aptamer pairs maximizes conformational changes of the aptagel, demonstrating a detection limit of 160-250 nM for vancomycin (6-9 fold improvement over monolayer counterpart) with a broad linear sensing range up to 1 mM. The aptagel maintains stability over 24 h in blood serum and 5 weeks in diluted blood plasma (mimicking interstitial fluid). This structurally responsive aptagel platform with superior stability and sensitivity offers promising avenues for continuous in vivo monitoring of small molecules.

• MeSH
• aptamery nukleotidové * chemie   MeSH
• biosenzitivní techniky * metody   MeSH
• hydrogely * chemie   MeSH
• lidé MeSH
• mikrorovnovážné techniky křemenného krystalu MeSH
• polyethylenglykoly chemie   MeSH
• povrchová plasmonová rezonance * metody   MeSH
• vankomycin * analýza   krev   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• Názvy látek
• aptamery nukleotidové * MeSH
• hydrogely * MeSH
• polyethylenglykoly MeSH
• vankomycin * MeSH

The need for biosensors has evolved in the detection of molecules, diseases, and pollution from various sources. This requirement has headed to the development of accurate and powerful equipment for analysis using biological sensing component as a biosensor. Biosensors have the advantage of rapid detection that can beat the conventional methods for the detection of the same molecules. Bio-chemiluminescence-based sensors are very sensitive during use in biological immune assay systems. Optical biosensors are emerging with time as they have the advantage that they act with a change in the refractive index. Carbon nanotube-based sensors are another area that has an important role in the biosensor field. Bioluminescence gives much higher quantum yields than classical chemiluminescence. Electro-generated bioluminescence has the advantage of miniature size and can produce a high signal-to-noise ratio and the controlled emission. Recent advances in biological techniques and instrumentation involving fluorescence tag to nanomaterials have increased the sensitivity limit of biosensors. Integrated approaches provided a better perspective for developing specific and sensitive biosensors with high regenerative potentials. This paper mainly focuses on sensors that are important for the detection of multiple molecules related to clinical and environmental applications. KEY POINTS: • The review focusses on the applications of luminescence-based, surface plasmon resonance-based, carbon nanotube-based, and graphene-based biosensors • Potential clinical, environmental, agricultural, and food industry applications/uses of biosensors have been critically reviewed • The current limitations in this field are discussed, as well as the prospects for future advancement.

• Klíčová slova
• Agriculture and food industry, Bio-chemiluminescence, Biosensors, Carbon nanotubes, Diseases, Environmental application, Graphene, Pollution,
• MeSH
• biosenzitivní techniky * MeSH
• grafit * MeSH
• luminiscence MeSH
• nanotrubičky uhlíkové * MeSH
• povrchová plasmonová rezonance MeSH
• Publikační typ
• časopisecké články MeSH
• přehledy MeSH
• Názvy látek
• grafit * MeSH
• nanotrubičky uhlíkové * MeSH

Cells are continuously sensing their microenvironment and subsequently respond to different physicochemical cues by the activation or inhibition of different signaling pathways. To study a very complex cellular response, it is necessary to diminish background environmental influences and highlight the particular event. However, surface-driven nonspecific interactions of the abundant biomolecules from the environment influence the targeted cell response significantly. Yes-associated protein (YAP) translocation may serve as a marker of human hepatocellular carcinoma (Huh7) cell responses to the extracellular matrix and surface-mediated stresses. Here, we propose a platform of tunable functionable antifouling poly(carboxybetain) (pCB)-based brushes to achieve a molecularly clean background for studying arginine, glycine, and aspartic acid (RGD)-induced YAP-connected mechanotransduction. Using two different sets of RGD-functionalized zwitterionic antifouling coatings with varying compositions of the antifouling layer, a clear correlation of YAP distribution with RGD functionalization concentrations was observed. On the other hand, commonly used surface passivation by the oligo(ethylene glycol)-based self-assembled monolayer (SAM) shows no potential to induce dependency of the YAP distribution on RGD concentrations. The results indicate that the antifouling background is a crucial component of surface-based cellular response studies, and pCB-based zwitterionic antifouling brush architectures may serve as a potential next-generation easily functionable surface platform for the monitoring and quantification of cellular processes.

• Klíčová slova
• antifouling polymer brushes, cell mechanotransduction, cell signaling, functional biointerfaces, surface modification, zwitterionic material,
• MeSH
• akrylamidy chemie   MeSH
• biokompatibilní potahované materiály chemie   MeSH
• bioznečištění prevence a kontrola   MeSH
• buněčný převod mechanických signálů * MeSH
• extracelulární matrix metabolismus   MeSH
• lidé MeSH
• mechanický stres MeSH
• nádorové buněčné linie MeSH
• oligopeptidy chemie   MeSH
• protoonkogenní proteiny c-yes metabolismus   MeSH
• Check Tag
• lidé MeSH
• Publikační typ
• časopisecké články MeSH
• práce podpořená grantem MeSH
• Názvy látek
• akrylamidy MeSH
• arginyl-glycyl-aspartic acid MeSH Prohlížeč
• biokompatibilní potahované materiály MeSH
• oligopeptidy MeSH
• protoonkogenní proteiny c-yes MeSH
• YES1 protein, human MeSH Prohlížeč
• zwitterion carboxybetaine acrylamide MeSH Prohlížeč