Tetrodotoxin Derivatization with a Newly Designed Boron Reagent Leads to Conventional Reversed-Phase Liquid Chromatography.

Tetrodotoxin (TTX) is a representative natural toxin causing pufferfish food poisoning, which is especially prominent in East and Southeast Asia, including Japan. TTX has been analyzed through post-column derivatization high-performance liquid chromatography (HPLC), ion-pair LC-MS(/MS), and hydrophilic interaction liquid chromatography (HILIC)-MS(/MS) as alternatives to the mouse bioassay method. However, post-column derivatization requires a system for online derivatization reactions, and with the ion-pair LC-MS approach, it is difficult to remove residual ion-pair reagents remaining in the equipment. Moreover, HILIC-MS provides poor separation compared to reversed-phase (RP) HPLC and requires a long time to reach equilibration. Therefore, we decided to develop a TTX analytical method using pre-column derivatization and RP HPLC for the rapid assessment of outbreak samples, including food remnants. In this study, we focused on the vic-diol moiety of TTX and designed a new derivatization reagent coded as NBD-H-DAB. This NBD-H-DAB was synthesized from 4-hydrazino-7-nitro-2,1,3-benzoxadiazole (NBD-H) and 3-fluoro-2-formylphenylboronic acid (FFPBA) with a simple reaction system and rapidly converted to its boronate form, coded NBD-H-PBA, in an aqueous reaction solution. The NBD-H-PBA demonstrated appropriate hydrophobicity to be retained on the RP analytical column and successfully detected with a UV spectrometer. It was easily reacted with the vic-diol moiety of TTX (C6 and C11) to synthesized a boronic ester. The derivatized TTX could be detected using the RP HPLC-UV, and the limit of detection in the fish flesh samples was 0.06 mg/kg. This novel pre-column derivatization of TTX with NBD-H-PBA proves capable for the analysis of TTX.

Active control of pharmacokinetics using light-responsive polymer-drug conjugates for boron neutron capture therapy.

In boron neutron capture therapy (BNCT), boron drugs should exhibit high intratumoral boron concentrations during neutron irradiation, while being cleared from the blood and normal organs. However, it is usually challenging to achieve such tumor accumulation and quick clearance simultaneously in a temporally controlled manner. Here, we developed a polymer-drug conjugate that can actively control the clearance of the drugs from the blood. This polymer-drug conjugate is based on a biocompatible polymer that passively accumulates in tumors. Its side chains were conjugated with the low-molecular-weight boron drugs, which are immediately excreted by the kidneys, via photolabile linkers. In a murine subcutaneous tumor model, the polymer-drug conjugate could accumulate in the tumor with the high boron concentration ratio of the tumor to the surrounding normal tissue (∼10) after intravenous injection while a considerable amount remained in the bloodstream as well. Photoirradiation to blood vessels through the skin surface cleaved the linker to release the boron drug in the blood, allowing for its rapid clearance from the bloodstream. Meanwhile, the boron concentration in the tumor which was not photoirradiated could be maintained high, permitting strong BNCT effects. In clinical BNCT, the dose of thermal neutrons to solid tumors is determined by the maximum radiation exposure to normal organs. Thus, our polymer-drug conjugate may enable us to increase the therapeutic radiation dose to tumors in such a practical situation.

Heat-resistant boron-nitrogen doped lignin-derived adsorbent-catalyst for gaseous aromatic pollutants removal.

Lignin-based carbon material can be utilized as carbonaceous adsorbents for the removal of toxic gaseous organic pollutants, while the poor heat-resistance limited its widely application. Here in, B-N co-doped lignin carbon (BN-C) with high thermal stability was synthesized, and the optimized BN-C (1:2) exhibited notably improved heat resistance with the decomposition temperature up to 505 °C, and excellent adsorption capacity for o-dichlorobenzene (o-DCB) (1510.0 mg/g) and toluene (947.3 mg/g), together with good cyclic stability over 10 cycles for o-dichlorobenzene. The existence of abundant hexagonal boron nitride (h-BN) with good thermal conductivity contributed to the superior heat-resistance of BN-C (1:2), and the high specific surface area (1764.5 m2/g), enriched hydroxyl functional groups and improved graphitization degree contributed to its enhanced adsorption performance. More importantly, BN-C (1:2) supported Ru could effectively remove o-DCB and toluene at wide temperature range (50-300 °C). The present work guided the development of heat-resistant lignin-derived adsorbent-catalyst for gaseous aromatic pollutants removal, which benefits both environmental protection and resource utilization.

Enhanced boron removal via seed-induced crystal growth of barium perborate in sequential fluidized-bed crystallization.

Chemical oxo-precipitation (COP) is an enhanced precipitation method for boron removal with the conversion of boric acid to perborate anions. When using barium-based precipitant, the boron can be effectively precipitated as barium perborates (BaPBs). The phase transformation of BaPBs from amorphous (A-BaPB, Ba(B(OH)3OOH)2) to crystalline (C-BaPB, BaB2(OO)2(OH)4) form is crucial for effective boron removal. However, scaling up this phase transformation of BaPBs is hindered by poor diffusion. This study aims to promote the growth of C-BaPB through seed-induced crystal growth, eliminating the need for phase transformation. By examining the relationship between crystal growth rate and supersaturation, surface spiral growth was identified as the rate-limiting step of the growth of micron-sized seeds near pHpzc. To enable continuous crystal growth, granular seeds of C-BaPB were prepared and employed as the medium for fluidized-bed crystallization (FBC). The system reached steady state 3 hydraulic retention times, achieving 90% boron removal. The effect of surface loading, ionic strength, and dosages on steady-state crystal growth rate was studied, revealing a shift of the rate-limiting step in FBC to diffusion. Lastly, the system that constituted of two FBCs in-series for sequential crystallization of A-BaPB and C-BaPB was demonstrated. The integrated system provided 97.8% of boron removal from synthetic wastewater containing 500 mg-B/L, with 92.3% of boron crystallized on the granular seeds of BaPBs.

Unveiling the Roles of Alloyed Boron in Hexavalent Chromium Removal Using Borohydride-Synthesized Nanoscale Zerovalent Iron: Electron Donor and Antipassivator.

Nanoscale zerovalent iron synthesized using borohydride (B-NZVI) has been widely applied in environmental remediation in recent decades. However, the contribution of boron in enhancing the inherent reactivity of B-NZVI and its effectiveness in removing hexavalent chromium [Cr(VI)] have not been well recognized and quantified. To the best of our knowledge, herein, a core-shell structure of B-NZVI featuring an Fe-B alloy shell beneath the iron oxide shell is demonstrated for the first time. Alloyed boron can reduce H+, contributing to more than 35.6% of H2 generation during acid digestion of B-NZVIs. In addition, alloyed B provides electrons for Fe3+ reduction during Cr(VI) removal, preventing in situ passivation of the reactive particle surface. Meanwhile, the amorphous oxide shell of B-NZVI exhibits an increased defect density, promoting the release of Fe2+ outside the shell to reduce Cr(VI), forming layer-structured precipitates and intense Fe-O bonds. Consequently, the surface-area-normalized capacity and surface reaction rate of B-NZVI are 6.5 and 6.9 times higher than those of crystalline NZVI, respectively. This study reveals the importance of alloyed B in Cr(VI) removal using B-NZVI and presents a comprehensive approach for investigating electron pathways and mechanisms involved in B-NZVIs for contaminant removal.

Antitumor Therapy through Photothermal Performance Synergized with Catalytic Activity Based on the Boron Cluster Supramolecular Frameworks.

Chemodynamic therapy (CDT) has received widespread attention as a tumor optical treatment strategy in the field of malignant tumor therapy. Nonmetallic multifunctional nanomaterials as CDT agents, due to their low toxicity, long-lasting effects, and safety characteristics, have promising applications in the integrated diagnosis and treatment of cancer. Here, we modified the supramolecular framework of boron clusters, coupled with a variety of dyes to develop a series of metal-free agent compounds, and demonstrated that these nonmetallic compounds have excellent CDT activities through experiments. Subsequently, the best performing Methylene Blue/[closo-B12H12]2- (MB@B12H12) was used as an example. Through theoretical calculations, electron paramagnetic resonance spectroscopy, and 808 nm light irradiation, we confirmed that MB@B12H12 exhibited photothermal performance and CDT activity further. More importantly, we applied MB@B12H12 to melanoma cells and subcutaneous tumor, demonstrating its effective suppression of melanoma growth in vitro and in vivo through the synergistic effects of photothermal performance and CDT activity. This study emphasizes the generalizability of the coupling of dyes to [closo-B12H12]2- with important clinical translational potential for CDT reagents. Among them, MB@B12H12 may have a brighter future, paving the way for the rapid development of metal-free CDT reagents.

Highly Sensitive and Selective Detection of L-Tryptophan by ECL Using Boron-Doped Diamond Electrodes.

L-tryptophan is an amino acid that is essential to the metabolism of humans. Therefore, there is a high interest for its detection in biological fluids including blood, urine, and saliva for medical studies, but also in food products. Towards this goal, we report on a new electrochemiluminescence (ECL) method for L-tryptophan detection involving the in situ production of hydrogen peroxide at the surface of boron-doped diamond (BDD) electrodes. We demonstrate that the ECL response efficiency is directly related to H2O2 production at the electrode surface and propose a mechanism for the ECL emission of L-tryptophan. After optimizing the analytical conditions, we show that the ECL response to L-tryptophan is directly linear with concentration in the range of 0.005 to 1 µM. We achieved a limit of detection of 0.4 nM and limit of quantification of 1.4 nM in phosphate buffer saline (PBS, pH 7.4). Good selectivity against other indolic compounds (serotonin, 3-methylindole, tryptamine, indole) potentially found in biological fluids was observed, thus making this approach highly promising for quantifying L-tryptophan in a broad range of aqueous matrices of interest.

Electrochemical degradation of diclofenac generates unexpected thyroidogenic transformation products: Implications for environmental risk assessment.

Diclofenac (DCF) is an environmentally persistent, nonsteroidal anti-inflammatory drug (NSAID) with thyroid disrupting properties. Electrochemical advanced oxidation processes (eAOPs) can efficiently remove NSAIDs from wastewater. However, eAOPs can generate transformation products (TPs) with unknown chemical and biological characteristics. In this study, DCF was electrochemically degraded using a boron-doped diamond anode. Ultra-high performance liquid chromatography coupled with high-resolution mass spectrometry was used to analyze the TPs of DCF and elucidate its potential degradation pathways. The biological impact of DCF and its TPs was evaluated using the Xenopus Eleutheroembryo Thyroid Assay, employing a transgenic amphibian model to assess thyroid axis activity. As DCF degradation progressed, in vivo thyroid activity transitioned from anti-thyroid in non-treated samples to pro-thyroid in intermediately treated samples, implying the emergence of thyroid-active TPs with distinct modes of action compared to DCF. Molecular docking analysis revealed that certain TPs bind to the thyroid receptor, potentially triggering thyroid hormone-like responses. Moreover, acute toxicity occurred in intermediately degraded samples, indicating the generation of TPs exhibiting higher toxicity than DCF. Both acute toxicity and thyroid effects were mitigated with a prolonged degradation time. This study highlights the importance of integrating in vivo bioassays in the environmental risk assessment of novel degradation processes.

Boron Cluster Renders Organic Radicals Water-Stable for Photothermal Anti-Infections.

Water-stable organic radicals are promising photothermal conversion candidates for photothermal therapy (PTT). However, organic radicals are usually unstable in biological environments, which greatly hinders their wide application. Here, we have developed a chaotropic effect-based and photoinduced water-stable supramolecular radical (MB12-2) for efficient antibacterial PTT. The supramolecular radical precursor MB12-1 was constructed by the chaotropic effect between closo-dodecaborate cluster (B12H122-) and N,N'-dimethylated dipyridinium thiazolo [5,4-d] thiazole (MPT2+). Subsequently, with triethanolamine (TEOA) serving as an electron donor, MB12-1 could transform to its radical form MB12-2 through photoinduced electron transfer (PET) under 435-nm laser irradiation. The N2 adsorption-desorption analysis confirmed that MB12-2 was tightly packed through the introduction of B12H122-, which effectively enhanced its stability via a spatial site-blocked effect. Moreover, the half-life of MB12-2 in water was calculated through ultraviolet-visible light (UV-vis) absorption spectra results for periods as long as 20 days. In addition, in the skin infection model, MB12-2, as a wound dressing, showed remarkable photothermal antibacterial activity (>97%) under 660-nm laser irradiation and promoted wound healing. This study presents a simple method for designing long-term water-stable supramolecular radicals, offering a novel avenue for noncontact treatments for bacterial infections.

Valency-based structural properties of gamma-sheet of boron clusters.

Boron cluster sheets are two-dimensional boron atom-based formations called borophene. They are similar to the two-dimensional sheet known as graphene, which is composed of carbon atoms arranged in a hexagonal lattice. The unique electrical, mechanical, and thermal properties of borophene make it a sought-after substance for a variety of uses, such as catalysis, energy storage, and electronics. There are two ways to manufacture borophene: chemical vapor deposition and molecular beam epitaxy. Vertex-edge valency-based topological descriptors are a great example of a molecular descriptor that provides information on the connection of atoms in a molecule. These descriptions are based on the notion that a node's value in a molecular network is the sum of the valency of those atoms that are directly connected to that node. In this article, we discussed some novel vertex-edge (ve) and edge-vertex (ev) topological descriptors and found their formulations for the boron cluster or borophene sheets. Also, we show the numerical and graphical comparison of these descriptors in this article.

Boron-doped g-C3N4 supporting Cu nanozyme for colorimetric-fluorescent-smartphone detection of α-glucosidase.

BACKGROUND: Due to that the higher activity of nanozymes would bring outstanding performance for the nanozyme-based biosensing strategies, great efforts have been made by researchers to improve the catalytic activity of nanozymes, and novel nanozymes with high catalytic activity are desired. Considering the crucial role in controlling blood glucose level, strategies like colorimetric and chemiluminescence to monitor α-glucosidase are developed. However, multi-mode detection with higher sensitivity was insufficient. Therefore, developing triple-mode detection method for α-glucosidase based on great performance nanozyme is of great importance. RESULTS: In this work, a novel nanozyme Cu-BCN was synthesized by loading Cu on boron doped carbon substrate g-C3N4 and applied to the colorimetric-fluorescent-smartphone triple-mode detection of α-glucosidase. In the presence of H2O2, Cu-BCN catalyzed the generation of 1O2 from H2O2, 1O2 subsequently oxidized TMB to blue colored oxTMB. In the presence of hydroquinone (HQ), the ROS produced from H2O2 was consumed, inhibiting the oxidation of TMB, which endows the possibility of colorimetric and visual on-site detection of HQ. Further, due to that the fluorescence of Mg-CQDs at 444 nm could be quenched by oxTMB, HQ could also be quantified through fluorescent mode. Since α-glucosidase could efficiently hydrolyze α-arbutin into HQ, the sensitive detection of α-glucosidase was realized. Further, colorimetric paper-based device (c-PAD) was fabricated for on-site α-glucosidase detection. The LODs for α-glucosidase via three modes were 2.20, 1.62 and 2.83 U/L respectively, high sensitivities were realized. SIGNIFICANCE: The nanozyme Cu-BCN possesses higher peroxidase-like activity by doping boron to the substrate than non-doped Cu-CN. The proposed triple-mode detection of α-glucosidase is more sensitive than most previous reports, and is reliable when applied to practical sample. Further, the smartphone-based colorimetric paper-based analytical device (c-PAD) made of simple materials could also detect α-glucosidase sensitively. The smartphone-based on-site detection provided a convenient, instrument-free and sensitive sensing method for α-glucosidase.

Optoelectronic Response to the Fluor Ion Bond on 4-(4,4,5,5-Tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde.

Boronate esters are a class of compounds containing a boron atom bonded to two oxygen atoms in an ester group, often being used as precursors in the synthesis of other materials. The characterization of the structure and properties of esters is usually carried out by UV-visible, infrared, and nuclear magnetic resonance (NMR) spectroscopic techniques. With the aim to better understand our experimental data, in this article, the density functional theory (DFT) is used to analyze the UV-visible and infrared spectra, as well as the isotropic shielding and chemical shifts of the hydrogen atoms 1H, carbon 13C and boron 11B in the compound 4-(4,4,5,5-tetramethyl-1,3,2-dioxoborolan-2-yl)benzaldehyde. Furthermore, this study considers the change in its electronic and spectroscopic properties of this particular ester, when its boron atom is coordinated with a fluoride anion. The calculations were carried out using the LSDA and B3LYP functionals in Gaussian-16, and PBE in CASTEP. The results show that the B3LYP functional gives the best approximation to the experimental data. The formation of a coordinated covalent B-F bond highlights the remarkable sensitivity of the NMR chemical shifts of carbon, oxygen, and boron atoms and their surroundings. Furthermore, this bond also highlights the changes in the electron transitions bands n → π* and π → π* during the absorption and emission of a photon in the UV-vis, and in the stretching bands of the C=C bonds, and bending of BO2 in the infrared spectrum. This study not only contributes to the understanding of the properties of boronate esters but also provides important information on the interactions and responses optoelectronic of the compound when is bonded to a fluorine atom.

Boron-doped reduced graphene oxide as an efficient cathode in microbial fuel cells for biological toxicity detection.

Electrodes with superior stability and sensitivity are highly desirable in advancing the toxicity detection efficiency of microbial fuel cells (MFCs). Herein, boron-doped reduced graphene oxide (B-rGO) was synthesized and utilized as an efficient cathode candidate in an MFCs system for sensitive sodium dodecylbenzene sulfonate (SDBS) detection. Boron doping introduces additional defects and improves the dispersibility and oxygen permeability, thereby enhancing the oxygen reduction reaction (ORR) efficiency. The B-rGO-based cathode has demonstrated significantly improved output voltage and power density, marking improvements of 75 % and 58 % over their undoped counterparts, respectively. Furthermore, it also exhibited remarkable linear sensitivity to SDBS concentrations across a broad range (0.2-15 mg/L). Notably, the cathode maintained excellent stability within the test range and showed significant reversibility for SDBS concentrations between 0.2 and 3 mg/L. The highly sensitive and stable B-rGO-based cathode is inspiring for developing more practical and cost-effective toxicant sensing devices.

BNCT pancreatic cancer treatment strategy with glucose-conjugated boron drug.

Multidisciplinary therapy centered on radical surgery for resectable pancreatic cancer is expected to prolong prognosis, but relies on CA19-9 biomarker levels to determine treatment strategy. Boron neutron capture therapy (BNCT) is a chemoradiotherapy using tumor hyperaccumulator boron drugs and neutron irradiation. The purpose of this study is to investigate novel boron drug agents for BNCT for pancreatic cancer. Bioinformatics was used to evaluate the uptake of current boron amino acid (BPA) drugs for BNCT into pancreatic cancer. The expression of the amino acid transporter LAT1, a BPA uptake transporter, was low in pancreatic cancer and even lower in high CA19-9 pancreatic cancer. In contrast, the glucose transporter was high in high CA19-9 pancreatic cancers and inversely correlated with LAT1 expression. Considering the low EPR effect in pancreatic cancer, we synthesized a small molecule Glucose-BSH, which is boron BSH bound to glucose, and confirmed its specific uptake in pancreatic cancer. uptake of Glucose-BSH was confirmed in an environment compatible with the tumor microenvironment. The therapeutic efficacy and safety of Glucose-BSH by therapeutic neutron irradiation were confirmed with BNCT. We report Glucose-BSH boron drug discovery study of a Precision Medicine BNCT with application to high CA19-9 pancreatic cancer.

Comprehensive risk assessment and interactions of fluoride and boron ions in the water-sediments interface: The Red Sea, Egypt.

This study presents a baseline evaluation of the distribution, human and ecotoxicological risk, and the potential interactions of fluoride and boron in the water-sediment interface in 25 locations from incredible Red Sea tourist destinations. Results showed comparable levels of B and F in the water and sediments with previous literature. Significant positive correlation was found between B and F (r = 0.57; P<0.01). Based on the sediment/liquid partition coefficient (Kd), F is more likely to be released from the sediment into seawater (logKd< 3) than B (3< logKd< 4). pH and alkalinity may affect water-sediment interactions of B and F, respectively, while SO42- and Cl- ions had no significant effect on adsorption ability of F and B. The majority of minerals had average saturation Index (SI) > 1 referring to the over saturation of seawater with these minerals and their inability to dissolve. The formation of CF, FAP, and CFAP may be related to the high correlation between Fw (r = 0.928, P< 0.01; r = 0.527, P< 0.01; r = 0.608, P< 0.01) and Bw (r = 0.38, P< 0.05; r = 0.38, P< 0.05; r = 0.397, P< 0.05). Total hazard quotient (THQ) for children and adults were <1, revealing no health risks from exposure to B and F through ingestion and skin contact while swimming. The risk characterization ratio; RCRmix(MEC/PNEC) showed high short-term risks to aquatic organisms. Further investigations might emphasis on emerging mitigation strategies to address these concerns.

Design of new boron-doped carbon dots for nano-level assay of nebivolol in human plasma and commercial products; Application to greenness assessments.

Recently, nanomaterials have attracted a lot of attention due to their potential as effective fluorescent nano-sensor probes. They were distinguishing substitutes for other luminescent techniques, such as fluorescent dyes and luminous derivatization, because of their affordability, environmental friendliness, and special photocatalytic properties. In the suggested work, a straightforward method was used to create boron and nitrogen carbon dots (B@CDs) with a good quantum yield value of 31.15 % utilizing boric acid and di-sodium EDTA. For the purpose of characterizing QDs, a variety of instruments were employed, such as transmission electron microscopy, fluorescence spectroscopy, X-ray FTIR, and UV-VIS spectroscopy. Nebivolol (NEB) is a cardiovascular medication used globally to treat congestive heart failure and hypertension, is in the meantime. For this reason, a brand-new, environmentally friendly analytical technique was created to determine the amount of human plasma, uniformity test, and commercial nebivolol (NEB) tablets. After gradually adding NEB, the response of B@CQDs was enhanced at 438 nm (excitation at 371 nm). The calibration graph ranged between 20 and 500 ng mL-1 with a quantification limit (LOQ) of 2.50 ng mL-1 and a detection limit (LOD) of 0.82 ng mL-1.

Size and Polarizability of Boron Cluster Carriers Modulate Chaotropic Membrane Transport.

Perhalogenated closo-borates represent a new class of membrane carriers. They owe this activity to their chaotropicity, which enables the transport of hydrophilic molecules across model membranes and into living cells. The transport efficiency of this new class of cluster carriers depends on a careful balance between their affinity to membranes and cargo, which varies with chaotropicity. However, the structure-activity parameters that define chaotropic transport remain to be elucidated. Here, we have studied the modulation of chaotropic transport by decoupling the halogen composition from the boron core size. The binding affinity between perhalogenated decaborate and dodecaborate clusters carriers was quantified with different hydrophilic model cargos, namely a neutral and a cationic peptide, phalloidin and (KLAKLAK)2. The transport efficiency, membrane-lytic properties, and cellular toxicity, as obtained from different vesicle and cell assays, increased with the size and polarizability of the clusters. These results validate the chaotropic effect as the driving force behind the membrane transport propensity of boron clusters. This work advances our understanding of the structural features of boron cluster carriers and establishes the first set of rational design principles for chaotropic membrane transporters.

Electrochemical needle sensor based on a B, N co-doped graphene microelectrode array for the on-site detection of salicylic acid in fruits and vegetables.

In this study, a microelectrode array sensor based on boron and nitrogen co-doped vertical graphene (BNVG) was assembled to quantify salicylic acid (SA) in living plants. The influence of B and N contents on the electrochemical reaction kinetics and SA response signal was investigated. A microneedle sensor with three optimized BNVG microelectrodes (3.57 at.% B and 3.27 at.% N) was used to quantitatively analyze SA in the 0.5-100 µM concentration range and pH 4.0-9.0, with limits of detection of 0.14-0.18 µM. Additionally, a quantitative electrochemical model database based on the BNVG microelectrode sensor was constructed to monitor the growth of cucumbers and cauliflowers, which confirmed that the SA level and plant growth rate were positively correlated. Moreover, the SA levels in various vegetables and fruits purchased from the market were measured to demonstrate the practical application prospects for on-site inspection and evaluation.

Carbon Dots Modified Multi Dopants Nitrogen and Boron for an Early Detection of Lead in the Environment.

The remarkable optical properties and strong biocompatibility of carbon dots make them highly promising for applications in biochemical sensing and environmental testing. These carbon dots possess a surface that is easily modifiable. In this study, carbon dots have been successfully synthesized and modified by the addition of N and B dopants using the microwave method, along with the functionalization of their surface functional groups with bovine serum albumin (BSA). The maximum fluorescence intensity of N, B-CDs is observed at 462 nm when excited at a wavelength of 352 nm. N, B-CDs have a spherical size with a diameter ranging from 2 to 6 nm, confirmed by UV-Vis absorption spectra and the presence of functional groups in the FT-IR absorption patterns. BSA-functionalized N, B-CDs as the fluorescent probe demonstrate great potential as a sensor for Pb(II) ions in water, with a very low detection limit of 1.05 µg/L. This research could contribute to the development of fluorescence nanosensors.

Novel, fast, and reliable electrochemical dsDNA biosensor based on O-terminated pristine nanocrystalline boron-doped diamond electrode for DNA interaction studies.

We present a novel application of a nanocrystalline boron-doped diamond electrode (B-NCDE) for the construction of an electrochemical DNA biosensor based on double-stranded DNA (dsDNA) for various bioanalytical applications. Surface characterization of the transducer surface (prior and after the fabrication of negatively charged O-terminated surface - O-B-NCDE) was performed by scanning electron microscopy (SEM), Raman spectroscopy, and linear sweep voltammetry (LSV) that was further used for the voltammetric determination, scan rate dependence investigation, and repeatability examination of dsDNA electrochemical oxidation at the O-B-NCDE. The fabrication of a dsDNA/O-B-NCDE biosensor via electrostatic adsorption of dsDNA involved a thorough optimization process of deposition potential (Edep), deposition time (tdep), and optimal saturation concentration (cg(satur)) with optimal values of 0.3 V, 3 min, and 10 mg/mL. The bioanalytical applicability of the fabricated dsDNA/O-B-NCDE biosensor was verified by examining the nature of the interaction between dsDNA and five selected DNA intercalators - namely thioridazine hydrochloride (TR), trimipramine maleate (TRIM), levomepromazine maleate (LEV), imipramine hydrochloride (IMI), and prochlorperazine maleate (PER) - where intercalation was proven for all of the five tested compounds. Moreover, the proposed novel bioanalytical test offers the possibility to selectively distinguish between the phenothiazine representatives (TR, LEV, and PER) and representatives of tricyclic antidepressants group (TRIM and IMI).