Sensitive and accurate monitoring of urinary albumin and point-of-care testing using a fluorescent probe with anti-interference capacity against exogenous drugs.

Fluorescent probes have been reported for monitoring urinary albumin (u-ALB) to enable early diagnosis of kidney diseases and facilitate regular point-of-care testing (POCT) for chronic kidney disease (CKD) patients. However, the albumin can bind hydrophobic drugs through host-guest interactions, which may result in decreased accuracy of probes at regular drug sites and hamper POCT of albuminuria since CKD patients often need to take medications routinely. Herein, we reported a novel fluorescent probe (NC-2) by molecular engineering of a reported AIEgen (NC-1). The introduction of a non-conjugated ring moiety to the molecular rotor granted the NC-2 enhanced sensitivity with a limit of detection in urine of 8.7 mg/L, which is below l the threshold of microalbuminuria (30 mg/L). Moreover, the NC-2 was found to preferentially bind to the FA1 site of ALB, conferring it with excellent anti-interference capacities against exogenous drug molecules and metabolites. Simulation experiments using lab-spiked urine samples containing common drugs taken by CKD patients demonstrated that the probe could provide satisfied detecting accuracy (80-90 %). Furthermore, a paper-based device was constructed and achieved on-site detection of u-ALB in qualitative and semi-quantitative manners. Findings in this work were of great significance to the development of fluorescent probes for accurate detection of ALB in complex urine samples and the further achievement of fluorescence-based POCT for CKD.

Recent Research Progress in Fluorescent Probes for Detection of Amyloid-ß In Vivo.

Alzheimer's disease (AD) is a neurodegenerative disease. Due to its complex pathological mechanism, its etiology is not yet clear. As one of the main pathological markers of AD, amyloid-ß (Aß) plays an important role in the development of AD. The deposition of Aß is not only related to the degeneration of neurons, but also can activate a series of pathological events, including the activation of astrocytes and microglia, the breakdown of the blood-brain barrier, and the change in microcirculation, which is the main cause of brain lesions and death in AD patients. Therefore, the development of efficient and reliable Aß-specific probes is crucial for the early diagnosis and treatment of AD. This paper focuses on reviewing the application of small-molecule fluorescent probes in Aß imaging in vivo in recent years. These probes efficiently map the presence of Aß in vivo, providing a pathway for the early diagnosis of AD and providing enlightenment for the design of Aß-specific probes in the future.

Recent Progress of Activity-Based Fluorescent Probes for Imaging Leucine Aminopeptidase.

Leucine aminopeptidase (LAP) is an important protease that can specifically hydrolyze Leucine residues. LAP occurs in microorganisms, plants, animals, and humans and is involved in a variety of physiological processes in the human body. In the physiological system, abnormal levels of LAP are associated with a variety of diseases and pathological processes, such as cancer and drug-induced liver injury; thus, LAP was chosen as the early biochemical marker for many physiological processes, including cancer. Considering the importance of LAP in physiological and pathological processes, it is critical that high-efficiency and dependable technology be developed to monitor LAP levels. Herein, we summarize the organic small molecule fluorescence/chemiluminescence probes used for LAP detection in recent years, which can image LAP in cancer, drug-induced liver injury (DILI), and bacteria. It can also reveal the role of LAP in tumors and differentiate the serum of cirrhotic, drug-induced liver injury and normal models.

Fluorescence Enhancement of Dicyanomethylene-4H-Pyran Derivatives in Solid State for Visualization of Latent Fingerprints.

The efficient development of latent fingerprint (LFP) is attractively important for criminal investigation. The low-cost and high-contrast developer is still a challenge. In this study, we designed and synthesized dicyanomethylene-4H-pyran (DCM) derivatives PZ-DCM and Boc-PZ-DCM by introducing of large steric hindrance group Boc, the solid-state fluorescence of DCM derivatives was greatly enhanced. The low-cost fluorescent LFP developers were prepared by blending with different proportion of montmorillonite (MMT). As a result, clear and high contrast fingerprint patterns were obtained with dusting method by the developer with 3% content of Boc-PZ-DCM. Furthermore, we employed the developer with 3% content of Boc-PZ-DCM to develop the sweat latent fingerprints on different substrates by powder dusting, and collected clear fingerprint patterns, indicating that the developer is universal. In a word, the Boc-PZ-DCM/MMT powder is a promising candidate for LFP developer.

Progress of Dicyanomethylene-4H-Pyran Derivatives in Biological Sensing Based on ICT Effect.

As one of the typical fluorescent cores, dicyanomethylene-4H-pyran (DCM) derivatives exhibit excellent photophysical and photochemical properties, such as large Stokes shift, excellent light stability, and tunable near-infrared (NIR) emission. The luminescence mechanism of DCM probes mainly depends on the intramolecular charge transfer (ICT). Hence, by regulating the ICT process, the probes can specifically act on the target molecule. Accordingly, a series of NIR DCM probes have been constructed to detect the ions, reactive oxygen species (ROS), and biological macromolecules in cells. However, there is no relevant review to summarize it at present. This minireview mainly summarizes the NIR DCM probes based on ICT effect and their applications in biosensors and biological imaging in recent years. This will be beneficial to innovatively construct new DCM probes and actively promote their application in the future.

Nonprecious bimetallic Fe, Mo-embedded N-enriched porous biochar for efficient oxidation of aqueous organic contaminants.

Bimetallic Fe- and Mo-embedded N-enriched porous biochar (Fe-Mo@N-BC) is developed and serves as a cost-effective and highly efficient catalyst for mineralization of non-biodegradation organic contaminants. Fe-Mo@N-BC was prepared by pyrolysis of complex Fe/Mo -containing precursors. Transmission electron microscopy and elemental mapping suggested that Fe and Mo are uniformly dispersed in nitrogen-doped biochar with hierarchical mesopores. In comparison to Fe@N-BC and Mo@N-BC, Fe-Mo@N-BC exhibited a superior activity for activating peroxymonosulfate (PMS). The stable activity was ascribed to N-doping and synergistic effect of Fe and Mo species, where both Fe-Nx and Mo-Nx can simultaneously serve as the active sites and N-BC can act as a carrier and an activator as well as an electron mediator. Electron paramagnetic resonance and quenching experiments indicated that HO•, O2•- and 1O2 were responsible for organic degradation. The effects of PMS dosage, initial Orange II concentration, temperature, solution pH, coexisting anions and humic acids on organic degradation were also investigated. With the assistance of an external magnet, Fe-Mo@N-BC can be easily separated after reaction and remains stable in the reusability tests. This work demonstrates a feasible strategy towards the fabrication of Fe, Mo-embedded N-enriched porous biochar catalysts for the detoxification of organic contaminants.

Synthesis and characterization of iron-nitrogen-doped biochar catalysts for organic pollutant removal and hexavalent chromium reduction.

Fe, N atoms deposited on porous biochar (Fe-N@BC) composites were synthesized and employed as an efficient catalyst for organic pollutant removal and CrVI reduction. Naturally abundant, renewable and N-rich pomelo peel as a carbon and nitrogen source and unsubstituted phthalocyanine/iron phthalocyanine complexes as a Fe and nitrogen resource were used to develop the Fe-N@BC via a carbonization process. It is found that Fe-N@BC hybrids have homogeneous dispersion of Fe and N atoms on 3D hierarchically porous biochar, which significantly improves the performance toward the detoxification of organic pollutants using peroxymonosulfate as an oxidant, as well as the reduction of hexavalent chromium by formic acid as a reductant. Furthermore, the effects of Fe loading and pyrolytic temperature on catalysis were comprehensively analyzed and optimized. The excellent activity of Fe-N@BC in acid media can be attributed to the high dispersion of Fe species, high content of doped nitrogen as well as hierarchical micro-mesopores, which induce to expose more active sites for catalysis. Owing to the structure-enabled acidic stability, Fe-N@BC efficiently retains its activity as well as its structural stability after several cycles of reactions. This work provides a new approach to construct Fe, N-doped biochar as an effective catalyst for the detoxification of organic and inorganic pollutants.