Self-Assembly Properties and Dynamics of Synthetic Proteo–Nucleic Building Blocks in Solution and on Surfaces

Strategies for the biological synthesis of D-glucuronic acid and its derivatives

D-glucuronic acid is a kind of glucose derivative, which has excellent properties such as anti-oxidation, treatment of liver disease and hyperlipidemia, and has been widely used in medicine, cosmetics, food and other fields. The traditional production methods of D-glucuronic acid mainly include natural extraction and chemical synthesis, which can no longer meet the growing market demand. The production of D-glucuronic acid by biocatalysis has become a promising alternative method because of its high efficiency and environmental friendliness. This review describes different production methods of D-glucuronic acid, including single enzyme catalysis, multi-enzyme cascade, whole cell catalysis and co-culture, as well as the intervention of some special catalysts. In addition, some feasible enzyme engineering strategies are provided, including the application of enzyme immobilized scaffold, enzyme mutation and high-throughput screening, which provide good ideas for the research of D-glucuronic acid biocatalysis.

Caught in Action: Visualizing Dynamic Nanostructures Within Supramolecular Systems Chemistry

Supramolecular systems chemistry has been an area of active research to develop nanomaterials with life-like functions. Progress in systems chemistry relies on our ability to probe the nanostructure formation in solution. Often visualizing the dynamics of nanostructures which transform over time is a formidable challenge. This necessitates a paradigm shift from dry sample imaging towards solution-based techniques. We review the application of state-of-the-art techniques for real-time, in situ visualization of dynamic self-assembly processes. We present how solution-based techniques namely optical super-resolution microscopy, solution-state atomic force microscopy, liquid-phase transmission electron microscopy, molecular dynamics simulations and other emerging techniques are revolutionizing our understanding of active and adaptive nanomaterials with life-like functions. This Review provides the visualization toolbox and futuristic vision to tap the potential of dynamic nanomaterials.

Microwave Spectroscopic Detection of Human Hsp70 Protein on Annealed Gold Nanostructures on ITO Glass Strips

Conductive indium-tin oxide (ITO) and non-conductive glass substrates were successfully modified with embedded gold nanoparticles (AuNPs) formed by controlled thermal annealing at 550 °C for 8 h in a preselected oven. The authors characterized the formation of AuNPs using two microscopic techniques: scanning electron microscopy (SEM) and atomic force microscopy (AFM). The analytical performances of the nanostructured-glasses were compared regarding biosensing of Hsp70, an ATP-driven molecular chaperone. In this work, the human heat-shock protein (Hsp70), was chosen as a model biomarker of body stress disorders for microwave spectroscopic investigations. It was found that microwave screening at 4 GHz allowed for the first time the detection of 12 ng/µL/cm² of Hsp70.

Atomic force microscopy: From red blood cells to immunohaematology

Atomic force microscopy (AFM) offers complementary imaging modes that can provide morphological and structural details of red blood cells (RBCs), and characterize interactions between specific biomolecules and RBC surface antigen. This review describes the applications of AFM in determining RBC health by the observation of cell morphology, elasticity and surface roughness. Measurement of interaction forces between plasma proteins and antibodies against RBC surface antigen using the AFM also brought new information to the immunohaematology field. With constant improvisation of the AFM in resolution and imaging time, the reaction of RBC to changes in the physico-chemistry of its environment and the presence of RBC surface antigen specific-biomolecules is achievable.

Biochip data normalization using multifunctional probes

Using a biochip with stable probe functionalization and a detection system capable of real time measurements, it is demonstrated that acquired probe-target interaction data are more reproducible in time--on a given probe spot using sequential target runs--than in space, using many probe spot replicates on the biochip in one single parallel target run. To increase the biochip data precision, a normalization method that quantifies and corrects the surface inhomogeneity without the use of complex data post-processing has been developed. This simple and effective method is based on adding a common reactive group to all probes and quantifying the biochip response to a calibration target, thus quantifying the spatial heterogeneity in the biosensor responsiveness. The usefulness of such methodology, which can be easily generalized, is demonstrated in the model case of DNA:DNA interactions, using a surface plasmon resonance imaging system as the dynamical reader. The biochips are based on streptavidin biochemically functionalized gold films onto which biotinylated ssDNA probe sequences, related to cystic fibrosis genotyping, are spotted. This normalization method provides high gain in data precision and allows, in this example, unambiguous genotyping of SNP, including discrimination of the heterozygote case from the two homozygote cases.