Ligand-Induced Red-Emitting Copper Nanoclusters for Selective Fluorescence Determination of Aluminum Ions.

Monitoring levels of excessive aluminum ions (Al) is crucial as it can harm the immune system, reduce enzyme activity, cause cell death, and damage environmental and biological systems. Developing a fast and efficient Al ion determination method is the key to addressing this issue. In this work, red-emitting fluorescent copper nanoclusters (CuNCs) were synthesized using -acetyl-l-cysteine (NAC) as a ligand and CuCl·2HO through a facile procedure.

Nitrogen-doped biomass-derived carbon dots for fluorescence determination of sunset yellow.

Sunset Yellow (SY) is a widely used food coloring in the food industry. However, exceeding the allowable limit of this dye poses a significant threat to human health. To address this issue, we developed -derived nitrogen-doped carbon dots (N-CDs) with a stable blue fluorescence through hydrothermal treatment for SY determination.

Biomass-derived carbon dots as emerging visual platforms for fluorescent sensing.

Biomass-derived carbon dots (CDs) are non-toxic and fluorescently stable, making them suitable for extensive application in fluorescence sensing. The use of cheap and renewable materials not only improves the utilization rate of waste resources, but it is also drawing increasing attention to and interest in the production of biomass-derived CDs. Visual fluorescence detection based on CDs is the focus of current research.

Visual Detection and Sensing of Mercury Ions and Glutathione Using Fluorescent Copper Nanoclusters.

Visual detection of mercury ions and glutathione is of great significance to public health and environmental issues. Herein, we developed a fluorescent sensor (l-Cys/CuNCs@ESM) based on the eggshell membrane (ESM) and red-emitting copper nanoclusters (CuNCs) by the in situ strategy via l-cysteine (l-Cys) as the reducing and protective agent for mercury ions and glutathione sensing visually. The as-prepared fluorescent product had good stability, portability, large Stokes shift (250 nm), and long fluorescence lifetime (7.

An alkaline phosphatase-induced immunosensor for SARS-CoV-2 N protein and cardiac troponin I based on the in situ fluorogenic self-assembly between N-heterocyclic boronic acids and alizarin red S.

Alkaline phosphatase (ALP)-induced in situ fluorescent immunosensor is less investigated and reported. Herein, a high-performance ALP-labeled in situ fluorescent immunoassay platform was constructed. The developed platform was based on a fluorogenic self-assembly reaction between pyridineboronic acid (PyB(OH)) and alizarin red S (ARS).

Yeast powder derived carbon quantum dots for dopamine detection and living cell imaging.

Dopamine (DA) is an important neurotransmitter in the brain of mammals. There is a critical need for fast and sensitive determination approaches to monitor these potential diseases due to various weaknesses in clinical trials of the existing methods for DA detection. DA can effectively quench the fluorescence of carbon quantum dots (CDs) through the inner filter effect and static quenching.

Simple construction of a two-component fluorescent sensor for turn-on detection of Hg in human serum.

The simply constructed fluorescent sensor with inexpensive reagents and low toxicity has attracted increasing attention contributing to its practical application. However, the common construction methods usually required a few building blocks and complex procedures, which is inconvenient for their further application. Herein, a simply constructed fluorescent Hg sensor has been developed based on the intrinsic fluorescence quenching power of G-quadruplex.

A colorimetric and ratiometric photometric sequential assay for ascorbic acid and alkaline phosphatase in serum based on valence states modulation.

The photometric method is widely used in real clinical tests due to its simple operation, low cost and convenient. Many of the reported colorimetric ALP assays so far are non- ratiometric because the detection was based on changes in absorbance at a single wavelength. The development of novel colorimetric and ratiometric assay is of importance for quantitatively measuring target with high accuracy.

A comparison of PMT-based and CCD-based sensors for electrochemiluminescence detection of sunset yellow in soft drinks.

The use of artificial colorants in food is highly regulated due to their potential to harm human health. Thus, it is crucial to detect these substances effectively to ensure conformance with industrial standards. In this work, we prepared a photomultiplier tube (PMT)-based electrochemiluminescence (ECL) sensor and a charged coupled device (CCD)-based ECL sensor and compared their merits in the detection of sunset yellow (SY) dye.

Novel synthesis of orange-red emitting copper nanoclusters stabilized by methionine as a fluorescent probe for norfloxacin sensing.

In the present work, we report a novel chemical approach for the synthesis of orange-red emitting copper nanoclusters (Cu NCs) using L-methionine as stabilizing agent at room temperature for the first time. The synthetic route is facile, economical and viable. The methionine stabilized copper nanoclusters (Cu NCs/Met) were thoroughly characterized by TEM, FT-IR, XPS, UV-Vis, steady state and transient fluorescence spectroscopy.

Design of a Fluorescence Turn-on and Label-free Aptasensor Using the Intrinsic Quenching Power of G-Quadruplex to AMT.

A novel fluorescent aptasensor based on the G-quadruplex induced fluorescent quenching of psoralen and the competitive interactions between 4'-aminomethyl-4,5',8-trimethylpsoralen (AMT), adenosine triphosphate (ATP) and G-rich DNA functionalized split ATP aptamer was proposed. The binding of ATP to the G-rich DNA functionalized split aptamer induced a significant enhancement in fluorescence emission intensity while undergoing excitation at 340 nm. Under the optimal conditions, the developed aptasensor showed high selectivity and good accuracy for detecting ATP.

In situ fabrication of a luminescent copper nanocluster/eggshell membrane composite and its application in visual detection of Ag ions, light-emitting diodes and surface patterning.

In this work, we report a novel strategy for fabricating a luminescent 2D nanocomposite at room temperature by in situ generation of luminescent copper nanoclusters (Cu NCs) embedded in natural monolithic eggshell membrane (ESM) using dithiothreitol as the reducing and capping agent. The established fabrication is facile, cost-effective and viable. The as-prepared Cu NC/ESM nanocomposite exhibited excellent photoluminescence performance, improved chemical, thermal and photo stability, convenient tailoring and flexibility.

Novel strategy to improve the sensing performances of split ATP aptamer based fluorescent indicator displacement assay through enhanced molecular recognition.

Split aptamer strategy was often used to improve the sensitivity of aptasensor. However, traditional split aptamer strategy can not be directly used to improve the label-free aptamer based Thioflavin T (ThT) displacement assay for ATP because the split ATP aptamer display much lower enhancement effects on the fluorescence of ThT than intact aptamer. In order to address this issue, this is the first report using G-rich DNA sequence to enhance the affinity of the two split ATP aptamer halves to ThT and offer lower limit of detection (LOD), wider linear range and higher selectivity through the enhanced molecular recognition.

In Situ Generation of Fluorescent Copper Nanoclusters Embedded in Monolithic Eggshell Membrane: Properties and Applications.

Luminescent metal nanoclusters have attracted considerable research attention in recent years due to their unique properties and extensive usage in many fields. Three different synthetic routes were developed to in situ generate orange and red emitting copper nanoclusters embedded in monolithic eggshell membrane (Cu NCs@ESM) using different reducing reagents including N₂H₄·H₂O, NH₂OH·HCl and Vitamin C at room temperature for the first time. The routes are extremely facile, low-cost and versatile.

Visual detection of sub-femtomole DNA by a gold nanoparticle seeded homogeneous reduction assay: toward a generalized sensitivity-enhancing strategy.

Gold nanoparticles (AuNPs) have been employed to design colorimetric visual sensing assays toward the detections of various targets including DNA, based on the aggregation induced color transitions of AuNPs. However, the relatively high detection limit (LOD 10nM) in the case of DNA detection has become a stumbling block on the road of the further development and applications of these assays. This research aims at overcoming this limit by virtue of a seeded gold reduction strategy.

Colorimetric Hg2+ detection with a label-free and fully DNA-structured sensor assembly incorporating G-quadruplex halves.

A sensitive and fully DNA-structured ion sensor was built by integrating polyT sequences for highly selective Hg2+ recognitions and two flanking G-quadruplex halves for allosteric signal transductions. The construction of this sensor was very easy that allowed a cost-effective detection of Hg2+ with a limit of detection of 4.5 nM, which was lower than the 10 nM toxic level for drinkable water as regulated by the US's EPA.

Rational design of an optical adenosine sensor by conjugating a DNA aptamer with split DNAzyme halves.

Split halves of a hemin-binding DNAzyme have been assembled with an anti-adenosine aptamer to build a homogeneous allosteric sensor for adenosine with high selectivity and sensitivity.