Lipoarabinomannan-based tuberculosis diagnosis using a fiber cavity ring down biosensor

Despite existing for millennia, tuberculosis (TB) remains a persistent global health challenge. A significant obstacle in controlling TB spread is the need for a rapid, portable, sensitive, and accurate diagnostic test. Currently, sputum culture stands as a benchmark test for TB diagnosis. Although highly reliable, it necessitates advanced laboratory facilities and involves considerable testing time. In this context, we present a rapid, portable, and cost-effective optical fiber sensor designed to measure lipoarabinomannan (LAM), a TB biomarker found in patients' urine samples. Our sensing approach is based on the applications of phase shift-cavity ringdown spectroscopy (PS-CRDS) to an optical fiber cavity created by two fiber Bragg gratings. A tapered fiber is spliced inside the optical cavity to serve as the sensing head. We functionalize the tapered fiber surface with anti-LAM antigen CS-35 through a unique chemistry, creating a strong affinity for LAM molecules. We measure the phase difference between the cavity transmission and the reference modulating signal at the cavity output. The measured phase is directly proportional to the injected LAM concentrations in aqueous solutions over the sensing head. Our demonstrated sensor provides a detection limit of 10 pg/mL and a sensitivity of 0.026°/pg/mL. This sensor holds promise for numerous applications in the healthcare sector, particularly in low-resource settings.

Industrial applications of immobilized nano-biocatalysts

Immobilized enzyme-based catalytic constructs could greatly improve various industrial processes due to their extraordinary catalytic activity and reaction specificity. In recent decades, nano-enzymes, defined as enzyme immobilized on nanomaterials, gained popularity for the enzymes' improved stability, reusability, and ease of separation from the biocatalytic process. Thus, enzymes can be strategically incorporated into nanostructured materials to engineer nano-enzymes, such as nanoporous particles, nanofibers, nanoflowers, nanogels, nanomembranes, metal-organic frameworks, multi-walled or single-walled carbon nanotubes, and nanoparticles with tuned shape and size. Surface-area-to-volume ratio, pore-volume, chemical compositions, electrical charge or conductivity of nanomaterials, protein charge, hydrophobicity, and amino acid composition on protein surface play fundamental roles in the nano-enzyme preparation and catalytic properties. With proper understanding, the optimization of the above-mentioned factors will lead to favorable micro-environments for biocatalysts of industrial relevance. Thus, the application of nano-enzymes promise to further strengthen the advances in catalysis, biotransformation, biosensing, and biomarker discovery. Herein, this review article spotlights recent progress in nano-enzyme development and their possible implementation in different areas, including biomedicine, biosensors, bioremediation of industrial pollutants, biofuel production, textile, leather, detergent, food industries and antifouling.

High Adsorption of α-Glucosidase on Polymer Brush-Modified Anisotropic Particles Acquired by Electrospraying-A Combined Experimental and Simulation Study

In this particular contribution, we aim to immobilize a model enzyme such as α-glucosidase onto poly(DMAEMA) [poly(2-dimethyl amino ethyl methacrylate)] brush-modified anisotropic (cup- and disc-shaped) biocompatible polymeric particles. The anisotropic particles comprising a blend of PLA [poly(lactide)] and poly(MMA-co-BEMA) [poly((methyl methacrylate)-co-(2-(2-bromopropionyloxy) ethyl methacrylate)] were acquired by electrospraying, a scalable and convenient technique. We have also demonstrated the role of a swollen polymer brush grafted on the surface of cup-/disc-shaped particles via surface-initiated atom transfer radical polymerization in immobilizing an unprecedentedly high loading of enzyme [441 mg/g (cup)-589 mg/g (disc) of particles, 15-20 times higher than that of the literature-reported system] as compared to non-brush-modified particles. Circular dichroism spectroscopy was used to predict the structural changes of the enzyme upon immobilization onto the carrier particles. An enormously high amount of enzymes with preserved activity (∼85 ± 13% for cups and ∼78 ± 15% for discs) was found to adhere onto brush-modified particles at pH 7 via electrostatic adsorption. These findings were further explored at the atomistic level using a coarse-grained dissipative particle dynamics simulation approach, which exhibited excellent correlation with experimental results. In addition, accelerated particle separation was also achieved via magnetic force-induced aggregation within 20 min (without a centrifuge) by incorporating magnetic nanoparticles into disc-shaped particles while electrojetting. This further strengthens the technical feasibility of the process, which holds immense potential to be applied for various enzymes intended for several applications.

Utilization of Biomass Fly Ash for Improving Quality of Organic Dye-Contaminated Water

Development of innovative methodologies to convert biomass ash into useful materials is essential to sustain the growing use of biomass for energy production. Herein, a simple chemical modification approach is employed to functionalize biomass fly ash (BFA) with 3-aminopropyltriethoxy silane (APTES) to develop an inexpensive and efficient adsorbent for water remediation. The amine-functionalized BFA (BFA-APTES) was fully characterized by employing a range of characterization techniques. Adsorption behavior of BFA-APTES was evaluated against two anionic dyes, namely, alizarin red S (ARS) and bromothymol blue (BTB). In the course of experimental data analysis, the computation tools of data fitting for linear and nonlinear form of Langmuir, Freundlich, and the modified Langmuir-Freundlich adsorption isotherms were used with the aid of Matlab R2019b. In order to highlight the misuse of linearization of adsorption models, the sum of the squares of residues (SSE) values obtained from nonlinear models are compared with R 2 values obtained from the linear regression. The accuracy of the data fitting was checked by the use of SSE as an error function instead of the coefficient of determination, R 2. The dye adsorption capacity of BFA-APTES was also compared with the nonfunctionalized BFA. The maximum adsorption capacities of BFA-APTES for ARS and BTB dye molecules were calculated to be around 13.42 and 15.44 mg/g, respectively. This value is approximately 2-3 times higher than the pristine BFA. A reasonable agreement between the calculated and experimental values of q e obtained from the nonlinear form of kinetic models verified the importance of using equations in their original form. The experimentally calculated thermodynamic parameters including molar standard Gibbs free energy (Δad G m 0) and molar standard enthalpy change (Δad H m 0) reflected that the process of adsorption of dye molecules on the BFA-APTES adsorbent was spontaneous and exothermic in nature. Moreover, the used BFA-APTES adsorbent could be regenerated and reused for several cycles with significant dye adsorption capacity. The remediation capability of the BFA-APTES adsorbent against ARS dye was also demonstrated by packing a small column filled with the BFA-APTES adsorbent and passing a solution of ARS through it. Overall, we provide a simple and scalable route to convert BFA into an efficient adsorbent for water remediation applications.

Biomolecular engineering for nanobio/bionanotechnology

Biomolecular engineering can be used to purposefully manipulate biomolecules, such as peptides, proteins, nucleic acids and lipids, within the framework of the relations among their structures, functions and properties, as well as their applicability to such areas as developing novel biomaterials, biosensing, bioimaging, and clinical diagnostics and therapeutics. Nanotechnology can also be used to design and tune the sizes, shapes, properties and functionality of nanomaterials. As such, there are considerable overlaps between nanotechnology and biomolecular engineering, in that both are concerned with the structure and behavior of materials on the nanometer scale or smaller. Therefore, in combination with nanotechnology, biomolecular engineering is expected to open up new fields of nanobio/bionanotechnology and to contribute to the development of novel nanobiomaterials, nanobiodevices and nanobiosystems. This review highlights recent studies using engineered biological molecules (e.g., oligonucleotides, peptides, proteins, enzymes, polysaccharides, lipids, biological cofactors and ligands) combined with functional nanomaterials in nanobio/bionanotechnology applications, including therapeutics, diagnostics, biosensing, bioanalysis and biocatalysts. Furthermore, this review focuses on five areas of recent advances in biomolecular engineering: (a) nucleic acid engineering, (b) gene engineering, (c) protein engineering, (d) chemical and enzymatic conjugation technologies, and (e) linker engineering. Precisely engineered nanobiomaterials, nanobiodevices and nanobiosystems are anticipated to emerge as next-generation platforms for bioelectronics, biosensors, biocatalysts, molecular imaging modalities, biological actuators, and biomedical applications.

Functionalized calcium silicate nanofibers with hierarchical structure derived from oyster shells and their application in heavy metal ions removal

Inorganic hierarchical nanostructures have remarkable potential applications in environmental metal remediation; however, their applications usually suffer from low capacity, high cost, and difficulties in the recycling of adsorbents. We previously reported a facile strategy to synthesize acid-insoluble calcium silicate hydrates (CSH) from oyster shells, a representative kind of biowaste. However, little is known of the structure, size, and morphology of the as-prepared CSH, which hampers the improvement of their adsorption capacities. In this work, systematic investigation of the structures of as-generated CSH demonstrate that they have a hierarchically porous structure composed of thin nano-sheets, where each nano-sheet is assembled by nano-fibers with width of around ten nanometers. The hierarchical nanostructures with pore size of ∼12 nm provide a significant amount of active sites to graft polyethyleneimine (PEI), which enables the efficient extraction of both Cu(ii) cations and Cr(vi) anions from the aqueous solution. Batch experiments further indicate that the PEI-modified PCSH exhibit a maximum adsorption capacity of 203 and 256 mg g(-1) for Cu(ii) and Cr(vi), respectively, much higher than that of CSH, OS and many other adsorbents in literature. The adsorption of Cu(ii) and Cr(vi) proved to be spontaneous and exothermic. Combining the pH-dependent experiments with X-ray photoelectron spectroscopy analysis, the underlying mechanism is discussed. PCSH derived from OS biowaste maintains an efficient extraction ability toward Cu(ii) and Cr(vi) after five adsorption-desorption cycles. It is also applicable for treating various kinds of heavy metal ions and organic pollutants, showing potentially wide applications in water treatment.

Polymer functionalized magnetic nanoconstructs for immunomagnetic separation of analytes

Core–shell polymer functionalized magnetic nanoparticles are promising material for rapid immunomagnetic separation and detection of analyte.

Hollow silica bubble based immobilized trypsin for highly efficient proteome digestion and buoyant separation

Tryptic digestion before identification and quantification by mass spectrometry is an indispensable process for most proteomics studies.

Collagenase@magnetite: proteolytic composite for magnetically targeted minimally invasive surgery

Fully biocompatible proteolytic magnetic nanocolloid providing high stability and prolonged activity has been developed.