Recognition Of Biomolecules Research Articles

Noncontact 3D Bioprinting of Proteinaceous Microarrays for Highly Sensitive Immunofluorescence Detection within Clinical Samples.

Immunofluorescence assays are extensively used for the detection of disease-associated biomarkers within patient samples for direct diagnosis. Unfortunately, these 2D microarrays suffer from low repeatability and fail to attain the low limits of detection (LODs) required to accurately discern disease progression for clinical monitoring. While three-dimensional microarrays with increased biorecognition molecule density stand to circumvent these limitations, their viscous component materials are not compatible with current microarray fabrication protocols. Herein, we introduce a platform for 3D microarray bioprinting, wherein a two-step printing approach enables the high-throughput fabrication of immunosorbent hydrogels. The hydrogels are composed entirely of cross-linked proteins decorated with clinically relevant capture antibodies. Compared to two-dimensional microarrays, these proteinaceous microarrays offer 3-fold increases in signal intensity. When tested with clinically relevant biomarkers, ultrasensitive single-plex and multiplex detection of interleukin-6 (LOD 0.3 pg/mL) and tumor necrosis factor receptor 1 (LOD 1 pg/mL) is observed. When challenged with clinical samples, these hydrogel microarrays consistently discern elevated levels of interleukin-6 in blood plasma derived from patients with systemic blood infections. Given their easy-to-implement, high-throughput fabrication, and ultrasensitive detection, these three-dimensional microarrays will enable better clinical monitoring of disease progression, yielding improved patient outcomes.

Tailoring Light–Matter Interactions in Overcoupled Resonator for Biomolecule Recognition and Detection

HighlightsProposed a new paradigm for nanoantenna design using coupled-mode theory.Designed an OC-Hµ resonator with excellent sensing performance.Using OC-Hµ resonators for biomolecule recognition and detection.

Progress of machine learning-based biosensors for the monitoring of food safety: A review

Rapid urbanization and growing food demand caused people to be concerned about food safety. Biosensors have gained considerable attention for assessing food safety due to selectivity, and sensitivity but poor stability inherently limits their application. The emergence of machine learning (ML) has enhanced the efficiency of different sensors for food safety assessment. The ML combined with various noninvasive biosensors has been implemented efficiently to monitor food safety by considering the stability of bio-recognition molecules. This review comprehensively summarizes the application of ML-powered biosensors to investigate food safety. Initially, different detector-based biosensors using biological molecules with their advantages and disadvantages and biosensor-related various ML algorithms for food safety monitoring have been discussed. Next, the application of ML-powered biosensors to detect antibiotics, foodborne microorganisms, mycotoxins, pesticides, heavy metals, anions, and persistent organic pollutants has been highlighted for the last five years. The challenges and prospects have also been deliberated. This review provides a new prospect in developing various biosensors for multi-food contaminants powered by suitable ML algorithms to monitor in-situ food safety.

Conformational Space Profiling Enhances Generic Molecular Representation for AI-Powered Ligand-Based Drug Discovery.

The molecular representation model is a neural network that converts molecular representations (SMILES, Graph) into feature vectors, and is an essential module applied across a wide range of artificial intelligence-driven drug discovery scenarios. However, current molecular representation models rarely consider the three-dimensional conformational space of molecules, losing sight of the dynamic nature of small molecules as well as the essence of molecular conformational space that covers the heterogeneity of molecule properties, such as the multi-target mechanism of action, recognition of different biomolecules, dynamics in cytoplasm and membrane. In this study, a new model named GeminiMol is proposed to incorporate conformational space profiles into molecular representation learning, which extracts the feature of capturing the complicated interplay between the molecular structure and the conformational space. Although GeminiMol is pre-trained on a relatively small-scale molecular dataset (39290 molecules), it shows balanced and superior performance not only on 67 molecular properties predictions but also on 73 cellular activity predictions and 171 zero-shot tasks (including virtual screening and target identification). By capturing the molecular conformational space profile, the strategy paves the way for rapid exploration of chemical space and facilitates changing paradigms for drug design.

Bio-functionalized conductive poly(acrylic acid):poly(3,4-Ethylenedioxythiophene)-Prussian blue hybrid transducer for biosensors and bioelectronics interfaces

This study presents an innovative organic-inorganic hybrid transducer of poly(acrylic acid) (PAA), poly(3,4-ethylenedioxythiophene) (PEDOT) and Prussian blue (PB) nanocatalysts. The transducer demonstrated functionality conducive to enzyme conjugation and exhibited favorable electrochemical properties for biosensor signal transduction. Fabricated by a one-tube chemical redox method, the PAA:PEDOT-PB transducer showed long-term electrocatalytic and structural stability. The performance of the transducer was characterized by high transduction activity and low charge transfer resistance, particularly for H2O2 reduction. It achieves a linear detection range from 1.0 μM to 4.0 mM, with a sensitivity of 494 ± 10 μA mM−1 cm−1 and a LOD of 0.34 μM. The PAA:PEDOT-PB transducer featured a high density of carboxyl groups (DCOOH = 14.64 ± 0.05 μmol cm−2) that promoted the immobilization of the H2O2-dependent oxidase enzyme lactate oxidase (LOx) with an EDC/S–NHS coupling agent. The LOx-PAA:PEDOT-PB transducer was developed for lactate biosensing. The transducer provided high LOx-enzyme affinity (KMapp = 1.47 ± 0.05 mM), and a rapid response time (10 s) for lactate detection across a concentration range of 5.0 μM to 4.0 mM, showing a sensitivity of 223 ± 3 μA mM−1 cm−1 and an LOD of 1.45 μM. The LOx-PAA:PEDOT-PB transducer was integrated with a flexible screen-printed electrode, incorporating a wireless, battery-free near-field communication potentiostat module to measure lactate in artificial sweat on a skin model via smartphone. The PAA:PEDOT-PB transducer could enable connections with multiple bio-recognition molecules through polycarboxylic acid groups, providing potential avenues for the development of advanced biosensors.

Label-free SELEX of aptamers for ultra-sensitive electrochemical aptasensor detection of amanitin in wild mushrooms

BackgroundMushroom poisoning poses a significant global health concern, with high morbidity and mortality rates. The primary lethal toxins responsible for this condition are alpha-amanitin (ɑ-AMA) and beta-amanitin (β-AMA). As a promising bio-recognition molecules in biosensors, aptamers, have been broadly used in the field of food detection. However, the current SELEX-based methods for screening aptamers for structurally similar small molecules were limited by the labelling or salt ion induction. In this study, we aimed to develop a novel label-free SELEX strategy for the screening of aptamers with high affinity and constructed new aptasensors for the detection of ɑ-AMA and β-AMA. ResultsA novel label-free SELEX strategy based on the positively charged gold nanoparticles (AuNPs) was proposed to simultaneous screening of aptamers for ɑ-AMA and β-AMA. Only 18 rounds of SELEX were required to obtain new aptamers. The candidate aptamers were analyzed by colloidal gold assay, and the sequences of ɑ-30 and β-37 displayed great affinity with Kd values of 22.26 nM and 23.32 nM, respectively, without interference from botanical toxins. Notably, the truncated aptamers ɑ-30-2 (50 bp) and β-37-2 (57 bp) exhibited higher affinity than their original counterpart (79 bp). Subsequently, the selected aptamers were utilized to construct recognition probes for electrochemical aptasensors based on hairpin cyclic cleavage of substrates by Cu2+ dependent DNAzyme and Exo I-triggered recycling cascades. The detection platform showed excellent analytical performance with limits of detection as low as 4.57 pg/mL (ɑ-AMA) and 8.49 pg/mL (β-AMA). Moreover, the aptasensors exhibited superior performance in mushroom and urine samples. SignificanceThis work developed a simple and efficient label-free SELEX method for screening new aptamers for ɑ-AMA and β-AMA, which employed the positively charged AuNPs as the screening medium, without the need for chemical labelling of libraries or induction of salt ions. Furthermore, two novel electrochemical aptasensors were developed based on our newly obtained aptamers, which offer the new biosensing tool for ultrasensitive detection of the AMA poisoning, showing great potential in practical applications.

(Invited) Carbon Nanostructures for Targeted Delivery and Health Monitoring in Plants

To meet the demand for food and bioenergy of a rapidly growing global population requires novel and convergent approaches to enhance photosynthetic organism function. Nanotechnology is enabling the development of targeted and species independent tools for advancing plant bioengineering and precision agriculture.My research group has developed carbon nanotube-based sensors capable of real-time sensing of plant signaling molecules. These nanosensors enabled the creation of plant sentinels that communicate the health status of plants to electronic devices. Near-infrared (nIR) fluorescent single-walled carbon nanotubes (SWCNTs) were designed and interfaced with plant leaves to report hydrogen peroxide (H2O2), a key signaling molecule associated with the onset of plant stress. The sensor nIR fluorescence response (>900 nm) is quenched by H2O2 with selectivity against other stress-associated signaling molecules and within the plant physiological range (10–100 H2O2 μM). In vivo remote nIR imaging of H2O2 sensors enabled optical monitoring of plant health in response to stresses including UV-B light (−11%), high light (−6%), and a pathogen-related peptide (flg22) (−10%), but not mechanical leaf wounding (<3%). The sensor’s high biocompatibility was reflected on similar leaf cell death (<5%) and photosynthetic rates to controls without SWCNT. These optical nanosensors report early signs of stress and will improve our understanding of plant stress communication, provide novel tools for precision agriculture, and optimize the use of agrochemicals in the environment.We also developed targeted carbon-based nanomaterials as tools for precise chemical delivery (carbon dots, CDs) and gene delivery platforms (SWCNTs) to plant organelles (chloroplasts) and vasculature (phloem). A biorecognition approach of coating the nanomaterials with a rationally designed chloroplast targeting peptide improved the delivery of CDs with molecular baskets (TP-β-CD) for delivery of agrochemicals and of plasmid DNA coated SWCNT (TP-pATV1-SWCNT) from 47% to 70% and from 39% to 57% of chloroplasts in leaves, respectively. Plants treated with TP-β-CD (20 mg/L) and TP-pATV1-SWCNT (2 mg/L) had a low percentage of dead cells, 6% and 8%, respectively, similar to controls without nanoparticles, and no permanent cell and chloroplast membrane damage after 5 days of exposure. Orthogonally, the surfaces of carbon dot nanocarriers were functionalized with sucrose, enabling rapid and efficient foliar delivery into the plant phloem, a vascular tissue that transports sugars, signaling molecules, and agrochemicals through the whole plant. The chemical affinity of sucrose molecules to sugar membrane transporters on the phloem cells enhances the uptake of biocompatible carbon dots with β-cyclodextrin molecular baskets (suc-β-CD) that can carry a wide range of agrochemicals. The nanoparticle fluorescence emission properties allowed detection and monitoring of rapid translocation (<40 min) in the vasculature of wheat leaves by confocal and epifluorescence microscopy. The suc-β-CDs more than doubled the delivery of chemical cargoes into the leaf vascular tissue. The sucrose coating of nanoparticles approach enables unprecedented targeted delivery to roots with ≈70% of phloem-loaded nanoparticles delivered to roots.The use of plant biorecognition molecules mediated delivery provides an approach for guiding nanocarriers with their cargoes to plant organelles, cells and tissues and whole plants and engineering safer and efficient agrochemical and biomolecule delivery tools. Communication and actuation of plants mediated by nanosensors and targeted nanostructures can turn plants into technology and lead to a more precise and sustainable agriculture with reduced environmental impact.

Synthesis of gold nanoparticles coated with glucose oxidase using PVP as passive adsorption linkage

Gold nanoparticles (AuNPs) have great potential as biosensors for glucose detection due to their high sensitivity, as well as their extraordinary physical and chemical properties that improve compatibility with different biorecognition molecules, such as glucose oxidase (GOx). In this work the D-glucose quantification was determined by using the traditional technique based on biochemical reaction of GOx and AuNPs functionalized with polyvinylpirrolidone (PVP) polymer and the enzyme. The AuNPs-PVP-GOx nanocomplexes were characterized by ultraviolet-visible (UV-Visible), Infrared (FTIR), and Raman spectroscopies, as well as scanning electron microscopy (SEM), Z potential, dynamic light scattering (DLS), and thermogravimetry analysis (TGA). In general, these techniques showed significant differences after each functionalization stage with PVP and GOx, for instance it was observed: the presence of different functional groups, an increase of hydrodynamic diameter from 48.60 to 198.77 nm, a shift of the band absorption to larger wavelength, a change in the surface potential and weight loss, and in the morphology of the nanocomplex, which confirm the functionalization. In addition, the enzymatic activity of the AuNPs-PVP-GOx was confirmed through the detection of triiodide ions by UV-Visible spectrophotometry, coming from the oxidation reaction of iodide ions in the presence of H2O2. Furthermore, the nanocomplex synthesized by passive adsorption was evaluated as a possible biosensor for the quantification of D-glucose using a colorimetric assay, obtaining greater sensitivity than the traditional method. These findings indicate that PVP can be used as a linkage medium between AuNPs and GOx, which in turn can be used as a biosensor for the detection of D-glucose at low concentrations in biological fluids.

Detection of 17-[formula omitted]-Ethinylestradiol with Bio-Functionalized tapered optical fiber sensor

This paper presents the utilization of tapered optical fiber (TOF) biosensor for the detection of 17-α-ethinylestradiol (EE2), an estrogen hormone. TOF with a waist diameter of 12 μm was fabricated from single mode fiber using heat and pull method. The tapered area was used as the sensing interface between the evanescent waves propagating around the fiber due to its unique geometry and the attached molecules on the tapered surface. EE2 antibodies were used as biorecognition molecules towards the targeted analyte, EE2. When tested with different concentrations of EE2 within the range of 0.1 ng/L – 1 mg/L, the developed sensor attained a detection limit of 1 ng/L with a sensitivity value of 1.088 nm/ngL-1 within the operation range of 1 – 10 ng/L. The specificity of the sensor was validated by testing the developed sensor with estrone (E1) and no significant wavelength shift was observed. These findings highlight the potential of our approach for sensitive and selective detection of EE2.

Emerging Biohybrids of Aptamer-Based Nano-Biosensing Technologies for Effective Early Cancer Detection.

Cancer is a leading global cause of mortality, which underscores the imperative of early detection for improved patient outcomes. Biorecognition molecules, especially aptamers, have emerged as highly effective tools for early and accurate cancer cell identification. Aptamers, with superior versatility in synthesis and modification, offer enhanced binding specificity and stability compared with conventional antibodies. Hence, this article reviews diagnostic strategies employing aptamer-based biohybrid nano-biosensing technologies, focusing on their utility in detecting cancer biomarkers and abnormal cells. Recent developments include the synthesis of nano-aptamers using diverse nanomaterials, such as metallic nanoparticles, metal oxide nanoparticles, carbon-derived substances, and biohybrid nanostructures. The integration of these nanomaterials with aptamers significantly enhances sensitivity and specificity, promising innovative and efficient approaches for cancer diagnosis. This convergence of nanotechnology with aptamer research holds the potential to revolutionize cancer treatment through rapid, accurate, and non-invasive diagnostic methods.

Highly sensitive and selective detection of dopamine using atomic layer deposited HfO2 ultra-thin films

The development of non-enzymatic and binder-free biosensors plays a vital role, and it possesses main benefits for effective biomolecule recognition with high sensitivity and preferred selectivity. Herein, an atomic layer deposition (ALD) was employed to develop the hafnium oxide (HfO2) nanofilm on silicon (Si) for fabricating binder-free selective and sensitive determination of the non-enzymatic electrochemical dopamine sensor. The prepared HfO2 nanofilm selectively acted as a local dopamine binding site because of the hydrophobic-hydrophobic interaction between fabricated film and dopamine, electrostatic attraction between negatively charged hydroxyl group on film surfaces, and positively charged amino group of dopamine. The developed insufficient oxygen vacancies on the HfO2 could have behaved as a charge-trapping site for better sensing properties. The developed sensor demonstrated excellent realization in sensing dopamine with a very low detection limit (0.4 pM) and swift response time of 3s which is quite precise compared with various reported literature. The fabricated HfO2/Si electrode sensor has exhibited high sensitivity, stability, and repeatability. The selectivity of dopamine sensors was at least three orders greater than other interfering biomolecules. This work proposes the essential track for the practical realization of dopamine detection in human serum and biomedical applications.

Split fluorescent protein-mediated multimerization of cell wall binding domain for highly sensitive and selective bacterial detection

Cell wall peptidoglycan binding domains (CBDs) of cell lytic enzymes, including bacteriocins, autolysins and bacteriophage endolysins, enable highly selective bacterial binding, and thus, have potential as biorecognition molecules for nondestructive bacterial detection. Here, a novel design for a self-complementing split fluorescent protein (FP) complex is proposed, where a multimeric FP chain fused with specific CBDs ((FP-CBD)n) is assembled inside the cell, to improve sensitivity by enhancing the signal generated upon Staphylococcus aureus or Bacillus anthracis binding. Flow cytometry shows enhanced fluorescence on the cell surface with increasing FP stoichiometry and surface plasmon resonance reveals nanomolar binding affinity to isolated peptidoglycan. The breadth of function of these complexes is demonstrated through the use of CBD modularity and the ability to attach enzymatic detection modalities. Horseradish peroxidase-coupled (FP-CBD)n complexes generate a catalytic amplification, with the degree of amplification increasing as a function of FP length, reaching a limit of detection (LOD) of 103 cells/droplet (approximately 0.1 ng S. aureus or B. anthracis) within 15 min on a polystyrene surface. These fusion proteins can be multiplexed for simultaneous detection. Multimeric split FP-CBD fusions enable use as a biorecognition molecule with enhanced signal for use in bacterial biosensing platforms.

Sensitivity, linearity, and noise evaluation of L‐shaped dielectrically modulated label free tunnel field‐effect transistor biosensor

AbstractThis research article examines a L‐shaped dielectrically modulated label free TFET (L‐DM‐TFET) biosensor for the purpose of detecting different biomolecules using a label‐free biosensing detection technique. The proposed structure allows for the recognition of biomolecules by modulating various electrical properties, such as the drain current, transconductance, and linearity parameters. The source region of the proposed TFET incorporates a SiGe (source)/Si (channel) heterojunction, utilizing a low bandgap material of SiGe. This heterojunction is employed to enhance the ON‐state current of the devices. The materials used and the fabrication steps involved in our proposed device are compatible with complementary metal‐oxide‐semiconductor (CMOS) technology. This analysis is conducted using a calibrated Silvaco technology computer‐aided design (TCAD) simulator. Additionally, by considering a dielectric constant range of 1–12, we calculate various figure of merits (FOMs) parameters for the device. These include evaluation of linearity, sensitivity, and noise characteristics. Furthermore, we have conducted an analysis of linearity FOMs, such as VIP2, VIP3, IIP3, and IMD3 for the proposed device under study. Additionally, the linearity analysis of the presented tunneling FET (TFET) indicates the device's excellent performance in distortionless switching operations. Consequently, the L‐shaped dielectrically modulated biosensor holds potential suitability for high‐speed circuit designs.

Development of an enzyme-linked phage receptor-binding protein assay (ELPRA) based on a novel biorecognition molecule- receptor-binding protein Gp130 of Pseudomonas aeruginosa bacteriophage Henu5

Pseudomonas aeruginosa is a Gram-negative bacterium associated with life-threatening healthcare-associated infections (HAIs), including burn wound infections, pneumonia and sepsis. Moreover, P. aeruginosa has been considered a pathogen of global concern due to its rising antibiotic resistance. Efficient identification of P. aeruginosa would significantly benefit the containment of bacterial infections, prevent pathogen transmission, and provide orientated treatment options. The accuracy and specificity of bacterial detection are primarily dictated by the biorecognition molecules employed. Lytic bacteriophages (or phages) could specifically attach to and lyse host bacterial cells. Phages’ host specificity is typically determined by their receptor-binding proteins (RBPs), which recognize and adsorb phages to particular bacterial host receptors. This makes RBPs promising biorecognition molecules in bacterial detection. This study identified a novel RBP (Gp130) from the P. aeruginosa phage Henu5. A modified enzyme-linked phage receptor-binding protein assay (ELPRA) was developed for P. aeruginosa detection employing Gp130 as biorecognition molecules. Optimized conditions provided a calibration curve for P. aeruginosa with a range from 1.0 × 103 to 1.0 × 107 CFU/mL, with a limit of detection as low as 10 CFU/mL in phosphate-buffered saline (PBS). With VITEKⓇ 2 Compact system identification (40 positives and 21 negatives) as the gold standard, the sensitivity of ELPRA was 0.950 (0.818–0.991), and the specificity was 0.905 (0.682–0.983) within a 95 %confidence interval. Moreover, the recovery test in spiked mouse serum showed recovery rates ranging from 82.79 %to 98.17%, demonstrating the prospect of the proposed ELPRA for detecting P. aeruginosa in biological samples.

Voltammetric determination of hemagglutinin using triazolotriazine derivatives as agents for the biomolecule recognition

An original approach for rapid voltammetric determination of the hemagglutinin (HA) protein using original new triazoloazine-based compounds as agents of biomolecule recognition was developed. A pronounced redox activity of original molecules was established; a possible mechanism of electrochemical conversion was proposed. The peak current of the nitro group electroreduction was chosen as an analytical signal. An efficient method for immobilizing the molecules on the surface of carbon nanotubes using thiol-ene and thiol-ine reactions with the radical initiator azobisisobutyronitrile has been proposed. The binding constants of the “compound-hemagglutinin” interaction were determined experimentally without and with external potential and calculated by the molecular modeling method. Compound 2-methylthio-6-nitro-7-oxo-4-propylene-1,2,4-triazolo-4,7-dihydro[5,1-c]-1,2,4-triazine(1a) showed the best characteristics of selective binding to the biotarget. A dependence of the analytical signal on the concentration of hemagglutinin in probe I* = -(13.1 ± 0.5) lgC + (93±2) was obtained in the range 10−7–10−3 M, the limit of detection calculated by the 3-sigma criteria was 7.0 10−8 M. The proposed approach has been successfully tested on saliva model solutions and anti-influenza vaccines.

Innovations in dengue virus detection: An overview of conventional and electrochemical biosensor approaches.

Globally, people are in great threat due to the highly spreading of viral infectious diseases. Every year like 100-300 million cases of infections are found, and among them, above 80% are not recognized and irrelevant. Dengue virus (DENV) is an arbovirus infection that currently infects people most frequently. DENV encompasses four viral serotypes, and they each express comparable sign. From a mild febrile sickness to a potentially fatal dengue hemorrhagic fever, dengue can induce a variety of symptoms. Presently, the globe is being challenged by the untimely identification of dengue infection. Therefore, this review summarizes advances in the detection of dengue from conventional methods (nucleic acid-based, polymerase chain reaction-based, and serological approaches) to novel biosensors. This work illustrates an extensive study of the current designs and fabrication approaches involved in the formation of electrochemical biosensors for untimely identifications of dengue. Additionally, in electrochemical sensing of DENV, we skimmed through significances of biorecognition molecules like lectins, nucleic acid, and antibodies. The introduction of emerging techniques such as the CRISPR/Cas' system and their integration with biosensing platforms has also been summarized. Furthermore, the review revealed the importance of electrochemical approach compared with traditional diagnostic methods.

Deaeration of incubation buffer to minimize electrochemical impedance spectroscopy signal drift on screen-printed gold electrodes and its use for label-free detection of vancomycin

Disposable screen-printed gold electrodes (SPAuEs) are used for the development of numerous immunosensors owing to their ease of modification with biorecognition molecules. A major limitation in the development of SPAuEs based biosensors is the single-use of the electrodes leading to higher costs for sensor development, whereas multiple measurements can affect the sensor stability and reproducibility. Especially, label-free electrochemical impedance spectroscopy (EIS) based SPAuEs sensors are prone to signal drift resulting in false-positive or false-negative data questioning the reliability of the assay. We found that repeated EIS measurements on SPAuEs in ferri- and ferrocyanide solution yielded a significant increase in resistance to charge transfer (Rct) value (positive signal drift) even in a control solution (without the target analyte). The positive signal drift follows the typical pattern of a concentration-dependent calibration curve, rendering repeated measurement error-prone for sensing purposes. In this study, it is shown that the incubation of the SPAuEs in nitrogen purged deaerated phosphate buffered saline (N-PBS) minimized this signal drift in repeated/multiple EIS measurements. This method was then used to develop a peptide-based EIS biosensor for the detection of Vancomycin, a last-line antibiotic used for the treatment of severe multidrug-resistant bacterial infection. This protocol can be followed for the biosensing of other clinically important biomarkers.

Supramolecular chemical biology: designed receptors and dynamic chemical systems.

Supramolecular chemistry focuses on the study of species joined by non-covalent interactions, and therefore on dynamic and relatively ill-defined structures. Despite being a well-developed field, it has to face important challenges when dealing with the selective recognition of biomolecules in highly competitive biomimetic media. However, supramolecular interactions reside at the core of chemical biology systems, since many processes in nature are governed by weak, non-covalent, strongly dynamic contacts. Therefore, there is a natural connection between these two research fields, which are not frequently related or share interests. In this feature article, I will highlight our most recent results in the molecular recognition of biologically relevant species, following different conceptual approaches from the most conventional design of elaborated receptors to the less popular dynamic combinatorial chemistry methodology. Selected illustrative examples from other groups will be also included. The discussion has been focused mainly on systems with potential biomedical applications.

Engineering copper plasmonic chirality via ligand-induced dissolution for enantioselective recognition of amino acids.

The formation of chiral nanosystems and their subsequent enantioselective interaction with chiral amino acids are vital steps in many biological processes. Due to their potential to mimic biological systems, the synthesis of chiral nanomaterials has garnered significant attention over the years. Despite the emergence of diverse nanomaterials showcasing strong chiral responses, the in-depth understanding of the mechanism of plasmonic chirality in copper nanoparticles and their subsequent application in various fields are least explored. Herein, we demonstrate a facile approach for the synthesis of chiral copper nanoparticles using cysteine as a chiral precursor and capping ligand. Ligand-mediated chiral induction, established through experimental findings and a theoretical model, is ascribed as the major contributor to the origin of plasmonic chirality. The enantioselective recognition of chiral copper nanoparticles towards histidine, an amino acid with vast biological functions, was meticulously investigated by leveraging the strong copper-histidine binding ability. Ligand-induced dissolution, a unique phenomenon in nanoparticle reactions, was identified as the underlying mechanism for the nanoparticle-to-complex conversion. Understanding the mechanism of chiral induction in copper nanoparticles coupled with their enantioselective recognition of biomolecules not only holds promise in biomedical research but also sheds light on their potential as catalysts for asymmetric synthesis.

Growth capacity of hybridoma clones producing monoclonal antibody against SARS-CoV-2 in low-serum media

Monoclonal antibodies (mAbs) are biorecognition molecules in the COVID-19 detection. Previously, we used the hybridoma technique to generate anti-Spike SARS-CoV-2 monoclonal antibodies. The resulting mAbs captured the commercial Spike protein of SARS-CoV-2 on an indirect ELISA platform, and afterward, the hybridomas were adapted to live in low-serum media. However, a validated hybridoma cell and a specific mAb should be established due to its critical role in large-scale production. Hence, this study aimed to observe the hybridoma cell’s growth capacity and its mAbs production in low-serum media. Two hybridoma clones, SF2 and RF10, were grown in RPMI media supplemented with 3% FBS for 11 days. Their viable cell density, growth rate, and doubling time were measured and calculated. According to the data, the SF2 clone grew slower than the RF10 clone. However, SF2 had shown greater cell density on the logarithmic phase. This finding is linear to the ELISA result, showing that SF2 produces higher absorbance levels. These findings demonstrated that the SF2 clone had the potential to survive under low-serum circumstances and still produce mAbs. This clone might be used to produce mAbs against Spike protein SARS-CoV-2 at a low cost.