CeO2 Nanowire-BODIPY-Adenosine Triphosphate Fluorescent Sensing Platform for Highly Specific and Sensitive Detection of Arsenate

Biocompatibility FeOOH QD@ATP-BODIPY nanocomposite for glutathione detection and intracellular imaging

Monitoring of glutathione has attracted considerable attention owing to its biological and clinical significance. An eco-friendly, economic, simple, biocompatible probe with excellent sensitivity and selectivity is very important. Herein, FeOOH QD@ATP-BODIPY nanocomposite was fabricated from one-step synthesized FeOOH quantum dots (FeOOH QD) and commercial boron-dipyrromethene-conjugated adenosine 5'-triphosphate (ATP-BODIPY) for glutathione (GSH) sensing in solutions and living cells. Three fascinate merits of FeOOH QD were confirmed: (a) as fluorescence quencher for ATP-BODIPY, (b) as selective recognizer of GSH and (c) with carrier effects and membrane permeability. The construction and response mechanism of the nanocomposite was based on the competitive coordination chemistry and redox reaction of FeOOH QD between GSH and phosphate group of ATP-BODIPY. Under the optimal conditions, the detection limit for GSH was as low as 68.8 nM. Excellent linear range of 0.2-400 μM was obtained. Furthermore, the chemical response of the nanocomposite exhibits high selectivity toward GSH over other electrolytes and biomolecules. It was successfully applied for GSH determination in human serum samples. The MTT assay exhibited FeOOH QD@ATP-BODIPY nanocomposite own good biocompatibility. FeOOH QD@ATP-BODIPY respond to GSH in living cells in situ was also proved via fluorescence imaging. These suggested that the FeOOH QD@ATP-BODIPY nanocomposite had potential application in biological and clinical applications.

NIR triggered polydopamine coated cerium dioxide nanozyme for ameliorating acute lung injury via enhanced ROS scavenging

Acute lung injury (ALI) is a life threatening disease in critically ill patients, and characterized by excessive reactive oxygen species (ROS) and inflammatory factors levels in the lung. Multiple evidences suggest that nanozyme with diversified catalytic capabilities plays a vital role in this fatal lung injury. At present, we developed a novel class of polydopamine (PDA) coated cerium dioxide (CeO2) nanozyme (Ce@P) that acts as the potent ROS scavenger for scavenging intracellular ROS and suppressing inflammatory responses against ALI. Herein, we aimed to identify that Ce@P combining with NIR irradiation could further strengthen its ROS scavenging capacity. Specifically, NIR triggered Ce@P exhibited the most potent antioxidant and anti-inflammatory behaviors in lipopolysaccharide (LPS) induced macrophages through decreasing the intracellular ROS levels, down-regulating the levels of TNF-α, IL-1β and IL-6, up-regulating the level of antioxidant cytokine (SOD-2), inducing M2 directional polarization (CD206 up-regulation), and increasing the expression level of HSP70. Besides, we performed intravenous (IV) injection of Ce@P in LPS induced ALI rat model, and found that it significantly accumulated in the lung tissue for 6 h after injection. It was also observed that Ce@P + NIR presented the superior behaviors of decreasing lung inflammation, alleviating diffuse alveolar damage, as well as promoting lung tissue repair. All in all, it has developed the strategy of using Ce@P combining with NIR irradiation for the synergistic enhanced treatment of ALI, which can serve as a promising therapeutic strategy for the clinical treatment of ROS derived diseases as well.

Arsenic field test kits based on solid-phase fluorescence filter effect induced by silver nanoparticle formation

Millions of people worldwide are affected by naturally occurring arsenic in groundwater. The development of a low-cost, highly sensitive, portable assay for rapid field detection of arsenic in water is important to identify areas for safe wells and to help prioritize testing. Herein, a novel paper-based fluorescence assay was developed for the on-site analysis of arsenic, which was constructed by the solid-phase fluorescence filter effect (SPFFE) of AsH3-induced the generation of silver nanoparticles (AgNPs) toward carbon dots. The proposed SPFFE-based assay achieves a low arsenic detection limit of 0.36 μg/L due to the efficient reduction of Ag+ by AsH3 and the high molar extinction coefficient of AgNPs. In conjunction with a smartphone and an integrated sample processing and sensing platform, field-sensitive detection of arsenic could be achieved. The accuracy of the portable assay was validated by successfully analyzing surface and groundwater samples, with no significant difference from the results obtained through mass spectrometry. Compared to other methods for arsenic analysis, this developed system offers excellent sensitivity, portability, and low cost. It holds promising potential for on-site analysis of arsenic in groundwater to identify safe well locations and quickly obtain output from the global map of groundwater arsenic.

BODIPY as a Multifunctional Theranostic Reagent in Biomedicine: Self-Assembly, Properties, and Applications

The use of boron dipyrromethene (BODIPY) in biomedicine is reviewed. To open, its synthesis and regulatory strategies are summarized, and inspiring cutting-edge work in post-functionalization strategies is highlighted. A brief overview of assembly model of BODIPY is then provided: BODIPY is introduced as a promising building block for the formation of single- and multicomponent self-assembled systems, including nanostructures suitable for aqueous environments, thereby showing the great development potential of supramolecular assembly in biomedicine applications. The frontier progress of BODIPY in biomedical application is thereafter described, supported by examples of the frontiers of biomedical applications of BODIPY-containing smart materials: it mainly involves the application of materials based on BODIPY building blocks and their assemblies in fluorescence bioimaging, photoacoustic imaging, disease treatment including photodynamic therapy, photothermal therapy, and immunotherapy. Lastly, not only the current status of the BODIPY family in the biomedical field but also the challenges worth considering are summarized. At the same time, insights into the future development prospects of biomedically applicable BODIPY are provided.

Nitrogen-doped carbon dots/Fe3+-based fluorescent probe for the "off-on" sensing of As(V) in seafood

To better satisfy the application of rapid detection methods in the detection of As(V) in complex food substrates, we developed an "off-on" fluorescence assay to detect As(V) based on the competition between the electron transfer effect of nitrogen-doped carbon dots (N-CDs)/Fe³⁺ and the complexation reaction of As(V)/Fe³⁺, using N-CDs/Fe³⁺ as a fluorescence probe. Solid-phase extraction (SPE) was used to eliminate matrix interference during sample pretreatment. The detection limit was 7.6 ng g^-1, with a linear range of 10-100 ng g^-1. The method was further used to determine As(V) in different seafood products including snapper, shrimp, clams, and kelp. At the same time, the recovery of the method was validated by high-performance liquid chromatography-inductively coupled plasma mass spectrometry (HPLC-ICP/MS), indicating that the developed method had good recoveries from 86% to 117% and met the needs for accurate determination of As(V). This approach has shown excellent application potential in the field of As(V) detection in various seafood products.

BODIPY-Based Nanomaterials—Sensing and Biomedical Applications

Cancerous diseases are rightfully considered among the most lethal, which have a consistently negative effect when considering official statistics in regular health reports around the globe. Nowadays, metallic nanoparticles can be potentially applied in medicine as active pharmaceuticals, adjustable carriers, or distinctive enhancers of physicochemical properties if combined with other drugs. Boron dipyrromethene (BODIPY) molecules have been considered for future applications in theranostics in the oncology field, thus expanding the potential of conceivable applicability. Hence, taking into account positive practical features of both metal-based nanostructures and BODIPY derivatives, the present study aims to gather recent results connected to BODIPY-conjugated metallic nanoparticles. This is with respect to their expediency in the diagnosis and treatment of tumor ailments as well as in sensing of heavy metals. To fulfill the designated objectives, multiple research documents were analyzed concerning the latest discoveries within the scope of BODIPY-based nanomaterials with particular emphasis on their utilization for diagnostical sensing as well as cancer diagnostics and therapy. In addition, collected examples of mentioned conjugates were presented in order to draw the attention of the scientific community to their practical applications, elucidate the topic in a consistent manner, and inspire fellow researchers for new findings.

SnO2 Nanoparticles-CeO2 Nanorods Enriched with Oxygen Vacancies for Bifunctional Sensing Performances toward Toxic CO Gas and Arsenate Ions

In this paper, we present a novel, one-step synthesis of SnO₂ nanoparticle-CeO₂ nanorod sensing material using a surfactant-mediated hydrothermal method. The bifunctional utility of the synthesized sensing material toward room-temperature sensing of CO gas and low-concentration optosensing of arsenic has been thoroughly investigated. The CeO₂-SnO₂ nanohybrid was characterized using sophisticated analytical techniques such as transmission electron microscopy, X-ray diffraction analysis, energy-dispersive X-ray analysis, X-ray photoelectron spectroscopy, and so forth. The CeO₂-SnO₂ nanohybrid-based sensor exhibited a strong response toward CO gas at room temperature. Under a low concentration (3 ppm) of CO gas, the CeO₂-SnO₂ sensing material showed an excellent response time of 21.1 s for 90% of the response was achieved with a higher recovery time of 59.6 s. The nanohybrid sensor showed excellent low-concentration (1 ppm) sensing behavior which is ∼6.7 times higher than that of the pristine SnO₂ sensors. The synergistically enhanced sensing properties of CeO₂-SnO₂ nanohybrid-based sensors were discussed from the viewpoint of the CeO₂-SnO₂ n-n heterojunction and the effect of oxygen vacancies. Furthermore, the SnO₂-CeO₂ nanoheterojunction showed luminescence centers and prolonged electron-hole recombination, thereby resulting in quenching of luminescence in the presence of arsenate ions. The photoluminescence of CeO₂-SnO₂ is sensitive to the arsenate ion concentration in water and can be used for sensing arsenate with a limit of detection of 4.5 ppb in a wide linear range of 0 to 100 ppb.

A competitive coordination-based immobilization-free electrochemical biosensor for highly sensitive detection of arsenic(v) using a CeO2-DNA nanoprobe

We developed a competitive coordination-based immobilization-free electrochemical biosensor for highly sensitive and selective detection of arsenic(v) using a CeO₂-DNA nanoprobe, which effectively circumvented complicated modification procedures and successfully achieved arsenic(v) determination in natural water samples.