Dual-emissive, oxygen-sensing boron nanoparticles quantify oxygen consumption rate in breast cancer cells

Doping of Mn2+ ion into boron quantum dots with enhanced fluorescence properties for sensing of L-thyroxine biomarker and bioimaging applications

L-thyroxine serves as a primary biomarker for diagnosing hypothyroidism and it is also utilized in hormone replacement therapy. Regular assessment of thyroxine levels is crucial for preventing health issues in hypothyroid patients, suggesting the requirement of a facile analytical tool for the detection of L-thyroxine. In this work, a straightforward and efficient synthetic method is introduced for in-situ preparation of Mn2+-doped boron quantum dots (Mn2+@B-QDs) derived from boron powder through a solvothermal reaction. The introduction of Mn2+ ion into B-QDs not only enhances fluorescence efficiency but also provides favorable sites within the QDs, expanding their potential applications in analytical chemistry. The blue fluorescent Mn2+ @B-QDs exhibited excellent performance for the selective recognition of L-thyroxine via a dynamic quenching mechanism. Under ideal conditions, a good linear relation was observed between the fluorescence emission intensity ratio of Mn2+@B-QDs and the concentration of L-thyroxine in the range of 0.125-5 μM, with a lower detection limit of 59.86 nM. The Mn2+@B-QDs exhibited the negligible cytotoxicity against A549 lung cancer cell lines and demonstrated good biocompatibility toward Saccharomyces cerevisiae cells.

Diclofenac enhances Boron nitride nanoparticle toxicity in freshwater green microalgae, Scenedesmus obliquus: Elucidating the role of oxidative stress

Boron nanoparticles have numerous medical, industrial, and environmental applications as potential nanomaterials. Given the inevitable release of these particles in aquatic environments, they can combine with other pollutants like pharmaceuticals. Therefore, it is necessary to investigate their combined detrimental effects on freshwater biota. This study examined the joint impacts of Boron nitride nanoparticles (BNNPs) and Diclofenac (DCF) on freshwater microalgae Scenedesmus obliquus. Three different concentrations of BNNPs (0.1, 1, and 10 mg L-1) were mixed with 1 mg L-1 of DCF and were treated with algal cells, and biochemical analyses were performed. A concentration-dependent decrease in algal cell viability was observed after a 72-h interaction period with BNNPs and their binary combinations. The maximum toxic effects were observed for the highest combination of BNNPs + DCF, i.e., 10 mg L-1 BNNPs + 1 mg L-1 DCF. Similarly, an increase in the oxidative stress parameters and antioxidant enzyme activity was observed, which correlated directly to the decline in cell viability. The algal cells also showed reduced photosynthetic efficiency and electron transfer rate upon interaction with BNNPs. The results of this research emphasize the importance of considering the negative consequences of emerging pollutants and their combinations with other pollutants, BNNPs, and DCF as part of a thorough evaluation of ecotoxicity in freshwater algal species.

Ag+-doped boron quantum dots with enhanced stability and fluorescence enabling versatile practicality in visual detection, sensing, imaging and photocatalytic degradation

In this work, a metal-doping strategy was put forward to construct metal-doped borophene and the corresponding zero-dimensional boron. Through theoretical calculations, Ag⁺ acts as the optimal metal ions to prepare Ag⁺-doped borophene derived boron quantum dots (Ag-BQDs). As predicted theoretically, doping of Ag⁺ endows borophene with enhanced stability of electronic structures. The newly emerging Ag-BQDs were experimentally acquired from ultrasonic-assisted liquid-phase exfoliation of bulk boron and solvothermal treatments. According to theoretical and experimental studies, the improved stability and fluorescence (FL) of Ag-BQDs are due to the formation of strong B-Ag bonding to competitively suppress B-O bonding. The function enables the maximal protection of borophene electronic structures from oxidization, destruction and reconfiguration. Because of Ag-BQDs with relatively higher colloidal and FL stability over BQDs, potential applications of Ag-BQDs were further explored in promising fields toward FL visualization in aqueous solutions and on filter paper, employed as a chemosensor of Fe³⁺ for FL sensing and visual detection at the solid/liquid phases, utilized for multiple FL bio-imaging at the levels of fresh plants, live animals and live cells of fresh plants, and applied to photocatalytic degradation of organic dyes and anticancer drug. Experimental results demonstrate excellent performances of Ag-BQDs in multiple applications, including versatile FL sensing and visual detection, unique multi-channel FL bio-imaging and visible-light-driven photodegradation of organic pollutants, toxic and harmful substances. This work can promote the development of metal-ion-doped low- dimensional nanomaterials with improved stability and FL properties for significant applications.

Metal-Doped Boron Quantum Dots for Versatile Detection of Lactate and Fluorescence Bioimaging

To improve the stability and fluorescence (FL) of monoelemental boron nanomaterials, this work put forward a metal-coordination strategy to explore emerging metal-doped boron quantum dots, Co@BQDs. Through theoretical calculations, B-Co bonding as predicted can suppress the B-O reaction and protect the electronic structures of exfoliated two-dimensional (2D) boron from oxidation and decomposition upon exposure to oxygen. In experimental studies, Co²⁺ was added into a dispersion liquid of bulk boron and subjected to probe sonication to promote Co²⁺ adsorption on the surface of exfoliated 2D boron, followed by Co²⁺ coordination with exposed boron atoms. Solvothermal treatment of exfoliated 2D boron resulted in the generation of Co²⁺-doped 0D boron Co@BQDs. Experimental results confirm that Co@BQDs have higher colloidal and FL stability than BQDs as a reference. B-Co bonding formation to suppress the B-O reaction ensures the high stability of exfoliated boron structures. A dispersion liquid of Co@BQDs with stable and bright FL was used for visual FL imaging of solutions and solid substrates. Based on enzymatic and cascade oxidation-induced FL quenching of Co@BQDs, a novel FL bio-probe of lactate was explored. This bio-probe, with a broad detection range of 0.01-10 mM and a low detection limit of 3.1 μM, enables FL sensing of lactate in biosamples and shows high detection recoveries of 98.0-102.8%. Moreover, this bio-probe realized versatile FL imaging and visual detection of lactate in liquid/solid-phase systems. These results demonstrate great prospects of Co@BQDs as emerging and efficient imaging reagents for long-term tracking and bioimaging applications.

Quantifying the effects of anesthesia on intracellular oxygen via low-cost portable microscopy using dual-emissive nanoparticles

Intracellular oxygenation is an important parameter for numerous biological studies. While there are a variety of methods available for acquiring in vivo measurements of oxygenation in animal models, most are dependent on indirect oxygen measurements, restraints, or anesthetization. A portable microscope system using a Raspberry Pi computer and Pi Camera was developed for attaching to murine dorsal window chambers. Dual-emissive boron nanoparticles were used as an oxygen-sensing probe while mice were imaged in awake and anesthetized states. The portable microscope system avoids altered in vivo measurements due to anesthesia or restraints while enabling increased continual acquisition durations.

Large-scale sensitivity adjustment for Gd-HMME room temperature phosphorescence oxygen sensing

The oxygen sensing enhancement based on room temperature phosphorescence (RTP) of Gd-HMME adjusted by imidazole was studied. The phosphorescence intensity I_P0 and the Stern-Volmer equations under different imidazole concentration were obtained, and the physical mechanism of imidazole regulating the oxygen quenching constant K_SV was analyzed. It was found that the K_SV value increased by ∼46 folds in the range of 12.4(1)-576.1(5) kPa^-1, and the large-scale variation of K_SV is conducive to the realization of high precision oxygen concentration measurement in a wide range. In addition, the standard deviation σ of continuous measurement results was given, and the limit of detection (LOD) was determined to be 6.6 ppm.