A Fluorescence Probe for Metal Ions Based on Black Phosphorus Quantum Dots

Abstract

spectroscopy (ICP-AES), and surface plasmon resonance sensing. [4][5][6] Although these methods have high detection performances, the complicated preprocessing process and the excessive cost limit their range of use and the detection rate. On the other hand, with the advancement of fluorescence technology, fluorescence detection techniques for metal ions by monitoring the fluorescence enhancement, quenching, or shifting of peak positions have attracted great interests. This type of method has advantages of strong visibility, simple operation, wide detection range, and low price. [7] Recently, quantum dot (QD) fluorescent probes are gradually receiving more attentions. Compared with the traditional organic fluorescent materials, QD fluorescent probes have narrower emission spectra, better stability, and photobleaching resistance. For example, carbon QDs, [8,9] CdSe QDs, [10] CdS QDs, [11] perovskites QDs, [12] and a combination of functional molecules and QDs have been studied to detect metal ions such as Fe 3+ , Pb 2+ , Hg 2+ , Zn 2+ , and Cd 2+ . [13][14][15][16][17][18] However, currently reported fluorescent probes can be used in only one solvent, it is therefore necessary to develop fluorescent probes with strong selectivity, wide detection range, and low detection limit, which can be used in both aqueous and organic solutions.Black phosphorus (BP) as one of the three major allotropes of phosphorus is a 2D van der Waals material whose atomic layers are stacked by weak van der Waals forces. BP can be stripped into nanosheets down to a single layer or quantum dots with bandgaps varying from 0.3 (bulk BP) to 2.0 eV. Due to this unique property, BP has the size and composition-dependent light absorption, long exciton lifetime, high photo luminescence quantum yield, and ability of surface modification. So far, BP has been used as photothermal agents, photodetectors, photocatalysts, organic photovoltaics, electrocatalysts, and the storage media. [19][20][21][22][23][24] BP has also been studied in the field of sensors, such as humidity sensors, [25] ratiometric fluorescent probes developed by the surface modification of organic molecules, [26,27] field effect transistor detection of metal ions. [28] In addition, BP has a wide range of applications in the biological field, including the medicine, drug carriers, and cancer treatment. [29][30][31] In this research, we have successfully prepared black phosphorus quantum dots (BP QDs) with green fluorescence emission, which can directly detect trace Hg 2+ and Cu 2+ ions without the help of organic molecules. In particular, Fluorescence method for detecting metal ions has advantages of fast detection speed, simple operation, and low price over the conventional methods. Black phosphorus quantum dots (BP QDs) have high photoluminescence quantum yield and modifiable surface, which have great potential in the field of fluorescent probes. In this study, high quality BP QDs are prepared by pyrolysis method and are first time used as trace metal ion probes in both organic solut...

Nanodots Derived from Layered Materials: Synthesis and Applications

“…A similar effect can be achieved by the incorporation of different surface functional groups or element doping. [206,211] Xu et al demonstrated a more practical Cu 2+ fluorescence probe based on BP QDs, which can be used in both aqueous and organic solutions. [211]…”

“…[206,211] Xu et al demonstrated a more practical Cu 2+ fluorescence probe based on BP QDs, which can be used in both aqueous and organic solutions. [211]…”

Ti3C2Tx MXene Nanosheet-Based Probe for Ion Fluorescence and Visual Detection of Ag+ in Aqueous Solution and Living Cells

“…A series of detection methods have been developed to detect silver ions, such as atomic absorption spectroscopy, inductively coupled plasma–mass spectroscopy, and ion-selective electrodes. , However, these methods mentioned above all require expensive equipment or complex technology. − On this basis, fluorescent probes have become a popular method due to their high sensitivity, rapidity, simple operation, common instruments, and suitability for biological systems. − In the past years, some fluorescent probes for detecting silver ions have been developed, but the following defects are still not solved. − First, some currently reported methods utilize the “silent ion” of silver ions to quench their fluorescence, which is not conducive to high signal output. , Second, the proposed probes only show moderate fluorescence changes, small response range to silver ion concentration, so the sensitivity of these probes is usually not enough to detect low concentrations of silver ions in water samples. , Finally, the probes reported in the literature are difficult to distinguish Ag + from other metal ions (such as Au 3+ ). , Therefore, it is an urgent need to develop a novel fluorescent probe with high sensitivity and selectivity in real samples. − …”

Interaction of L-Tryptophan with Selected Important Ions in Aqueous Solution

“…Atomic absorption spectroscopy, inductively coupled plasma mass spectroscopy (ICP-MS), X-Ray uorescence have been reported in the literature to be used for the detection of heavy metal ions in environmental samples. But however their use has been limited because of their high cost and complicated instrumentation [9,10,11,13,14].…”