Fluorescence Color Research Articles

Construction of an Artificial Sequential Light-Harvesting System and White-Light Material Utilizing Supramolecular Gels.

The molecular (pyren-1-yloxy)-acetic acid (Py) with excellent fluorescence properties was synthesized from 1-hydroxypyrene (Hp) and formed a supramolecular gel with an acid-base stimulus response in dimethylformamide and water. On the basis of gel, the fluorescent dye perylene 3, 9-dicarbxylic acid, and rhodamine 6g were added successively to construct a step-by-step artificial light-harvesting system, so that the fluorescence color changed from blue-purple to green to red, and white light emission was realized by adjusting the ratio of donors and acceptors.

Pyrene‐based ratiometric fluorescent chemosensor for sensitive detection of hypochlorite in a perfect aqueous solution

AbstractWe synthesized a pyrene‐based sensitive fluorescent chemosensor, TPA‐Cl ((E)‐N,N,N‐trimethyl‐2‐oxo‐2‐(2‐(pyren‐1‐ylmethylene)hydrazinyl)ethan‐1‐aminium chloride), to detect hypochlorite in a perfect aqueous solution. TPA‐Cl showed high selectivity for hypochlorite through fluorescence color change from sky blue to blue. The detection limit for hypochlorite was calculated as 0.27 μM, which is a quite low value. Moreover, the presence of other anions or ROS hardly hindered the sensing of hypochlorite by TPA‐Cl. Furthermore, TPA‐Cl could be applied successfully as a test kit for the simple recognition of hypochlorite. Surprisingly, TPA‐Cl is the first pyrene‐based fluorescent chemosensor that can detect ClO− by using the TPA‐Cl‐coated test kit. Moreover, TPA‐Cl could achieve the quantification of ClO− in various environmental water samples. The hydrolytic cleavage and oxidation mechanism of TPA‐Cl by hypochlorite was elucidated through UV–vis and fluorescent spectroscopy, 1H NMR titration, ESI‐MS analysis and DFT calculation.

Smartphone-based sensing and in vivo and in vitro imaging of Mn(VII) based on nitrogen-doped red fluorescent carbon dots.

Smartphone-assisted visual assay platform provides novel insight for the real-time in-field quantitation of intended analytes in resource-insufficient areas. Herein, nitrogen-doped red fluorescent (FL) carbon dots (R-CDs) were developed for the timely on-site quantitation of Mn(VII) using the smartphone-assisted assay platform. R-CDs, possessing a desirable bright red FL at 616 nm under a 470 nm excitation, were fabricated through hydrothermal treatment adopting passion fruit and neutral red as precursors. Interestingly, bright red FL at 616 nm are gradually quenched upon introducing Mn(VII) based on the inner filter effect, concurrently accompanying with significant FL color variation from bright red to dark red. Inspired by the above-mentioned phenomena, hue-saturation-values (HSV) of real-time captured images could be precisely quantified through a color recognition APP within the smartphone, of which the V/S values could be employed to quantify Mn(VII) with a linear range of 50-400 μM. Furthermore, confocal fluorescence imaging of HeLa cells and zebrafish larvae demonstrates that R-CDs could be employed for the visual determination of Mn(VII) in vivo and in vitro, illustrating that R-CDs possess powerful practical application prospect in biosystem.

Rhodamine‐based force‐sensitive organic polysiloxane for hardness recognition of inorganic particles

AbstractThe mechanochromic materials can respond to environmental changes by altering the optical properties of the system, which has garnered significant attention in recently. The utilization of these materials for the purpose of sensing tensile and compressive stress has been extensively documented. However, the mechanochromic polymer that can effectively discriminate hardness of inorganic particles is still rarely reported. In this article, a force‐sensitive organic polysiloxane was developed by introducing triethenyl‐substituted rhodamine derivatives crosslinker into the polymethylhydrosiloxane network through hydrosilylation addition reaction. The results demonstrated that the grinding of the crosslinked polysiloxane effectively facilitated the transmission of external force to the polymeric network, leading to an open ring isomerization of rhodamine accompanied by significant alterations in visible and fluorescent color. In addition, we found that the optical properties of the system showed distinct variations when the inorganic particles with different Moh's hardness were co‐ground with the polysiloxane. High Moh's hardness particles, such as Al2O3, could effectively trigger the mechanochromic behavior of the polymer, while Na2SO4 particles with low hardness failed to induce the corresponding change. Therefore, this organic polysiloxane could be used as a potential fluorescent indicator for hardness recognition.

Novel ratiometric fluorescent probe with large Stokes shift for selective sensing and imaging of Zn2+ in live cell

A novel ratiometric fluorescent probe, namely 5-[(3-dicyanoylidene −5.5-dimethyl) cyclohexenyl-1-ethenyl] salicylaldehyde-3′-hydroxybenzohydrazone (DCSH) is presented for the selective sensing of Zn2+ ion in acetonitrile/water (2/3, pH 7.4) solution. Introducing Zn2+ ions notably caused the peak emission of DCSH to shift from 560 nm to 646 nm, accompanied with a significant enhancement of its intensity. A vivid change in fluorescence color from yellow to red facilitated the immediate identification of Zn2+ ions by visual observation. DCSH exhibits substantial Stokes shifts (110 and 196 nm), rapid detection capability (within 10 s) and high sensitivity to Zn2+ ions, achieving a limit of detection of 31.2 nM. The response mechanism is supposed to involve the block of C = N bond isomerization and excited state intramolecular proton transfer (ESIPT) along with the enhancement of fluorescence through chelation (CHEF) effect. DCSH was effectively utilized for ratiometric fluorescence imaging to monitor exogenous Zn2+ concentrations in HeLa cells. Significantly, DCSH is capable of monitoring elevated levels of Zn2+ ion during apoptosis induced by L-Buthionine sulfoximine (BSO).

A novel dimer induced AIE smart material for fluorescence colorimetric detection of food freshness and Zn2+

A simple, smart material (2-(benzo[d]thiazol-2-yl)-4-hydroxy-7-methylphthalazin-1(2H)-one, BTHM) have been developed by one-step reaction, which displayed an aggregation-induced emission (AIE) effect because of due to the unique dimer formation by intermolecular hydrogen bonds by XRD measurements. BTHM exhibited strong solid-state emission and is sensitive to Et3N/CH2Cl2 vapor stimulus and could be used as a portable test strip for identifying different concentrations of Et3N/CH2Cl2 vapor. Also, it successfully realized blue/green luminescence switching by the external Et3N/AcOH vapor stimuli with a high repeatability. BTHM labels have been preferentially used for real-time and visual monitoring of the freshness of the pork and shrimp food. Also, the BTHM display fluorescence colorimetric response to Zn2+ in EtOH/H2O (1/9, V/V, pH=7.4) medium with high selectivity and sensitivity. Importantly, BTHM could be used to monitor Zn2+ in living A549 cells by an outstanding fluorescence color signal change. Further, the theoretical calculations have been performed to address the sensing mechanism.

Electrofluorochromic Hydrogels by Oligothiophene-Based Color-Tunable Fluorescent Dye Doping.

Soft electronic materials hold great promise for advancing flexible functional devices. Among the various soft materials available, hydrogels are particularly attractive for soft electronic device development due to their inherent properties, including transparency, shape adaptability through swelling/deswelling, and self-healing capabilities. Transparent hydrogels contribute to the creation of advanced smart devices such as sensors, smart windows, and anticounterfeiting technologies. Poly(vinyl alcohol) hydrogels are used as a platform for creating electrofluorochromic (EFC) devices in combination with oligothiophene-conjugated benzothiazole derivatives (OCBs) as fluorescent emitters. OCBs demonstrated excited-state intramolecular proton transfer (ESIPT) behavior with a large Stokes shift and emission changes responsive to solvent polarity and pH stimuli. Even in the solid state, OCBs exhibited strong fluorescence emission across a wide range of colors from blue to red, making them exceptionally well-suited for EFC device development. Their quantum yields in the powder state were obtained between 2.3% and 19.9%. Through the incorporation of OCBs into a PVA hydrogel (OCB@PVA), we achieved the successful fabrication of flexible EFC devices, including electronic paper and smart panels. When electric potentials (-2.4 and +2.4 V) were applied in OCB@PVA, fluorescence color changes were observed by an electrochemically induced pH change owing to electrohydrolysis of water. These devices demonstrated the potential of OCB@PVA hydrogels in the realm of flexible electronics. They could be used to create innovative and versatile devices with stimuli-responsive fluorescence properties.

Portable hydrogel kit based on Michael addition reaction for (E)-2-hexenal gas detection

Plants exhibit rapid responses to biotic and abiotic stresses by releasing a range of volatile organic compounds (VOCs). Monitoring changes in these VOCs holds the potential for the early detection of plant diseases. This study proposes a method for identifying late blight in potatoes based on the detection of (E)-2-hexenal, one of the major VOC markers released during plant infection by Phytophthora infestans. By combining the Michael addition reaction with cysteine-mediated etching of aggregation-induced emission gold nanoclusters (Au NCs), we have developed a portable hydrogel kit for on-site detection of (E)-2-hexenal. The Michael addition reaction between (E)-2-hexenal and cysteine effectively alleviates the etching of cysteine-mediated Au NCs, leading to a distinct fluorescence color change in the Au NCs, enabling a detection limit of 0.61 ppm. Utilizing the superior loading and diffusion characteristics of the three-dimensional structure of agarose hydrogel, our sensor demonstrated exceptional performance in terms of sensitivity, selectivity, reaction time, and ease of use. Moreover, quantitative measurement of (E)-2-hexenal was made easier by using ImageJ software to transform fluorescent images from the hydrogel kit into digital data. Such method was effectively used for the early detection of potato late blight. This study presents a low-cost, portable fluorescent analytical tool, offering a new avenue for on-site detection of plant diseases.

Dual-Mode Multicolor Display Based on Structural and Fluorescent Color CdS Photonic Crystal Hydrogel.

In this study, we prepared a multicolor structural-fluorescent CdS-PEGDA photonic crystal hydrogel (SFC-CPH) with a dual display mode, which has two different optical states: structural color mode and fluorescent color mode. SFC-CPH displays structural color mode under visible light and fluorescent color mode under ultraviolet light. Initially, monodisperse CdS colloidal particles were synthesized via a hydrothermal method, leading to the self-assembly of a photonic crystal template. The high refractive index of CdS contributes to the photonic crystals' low-angle dependence and vivid structural colors. Then, a variety of fluorescent molecules were doped into poly(ethylene glycol) diacrylate (PEGDA) hydrogel and combined with photonic crystals with distinct structural colors to prepare three distinct colors of SFC-CPH. We also investigated the optical characteristics and surface properties of these photonic crystal hydrogels. Based on these dual-mode display characteristics, we designed several dual-mode display patterns and a method for information encoding. The unique property of this photonic crystal hydrogel material suggests its substantial potential for applications in information storage, security, and encoding, offering innovative avenues in the realm of information display.

A dual-response ratiometric fluorescent sensor for oxytetracycline determination in milk and mutton samples

Owing to the adverse effects of oxytetracycline (OTC) residues on human health, it is of great importance to construct a rapid and effective strategy for OTC detection. Herein, we developed a dual-response fluorescence sensing platform based on molybdenum sulfide quantum dots (MoS2 QDs) and europium ions (Eu3+) for ratiometric detection of OTC. The MoS2 QDs, synthesized through an uncomplicated one-step hydrothermal approach, upon OTC integration into the MoS2 QDs/Eu3+ sensing system, exhibit a significant quenching of blue fluorescence due to the inner filter effect (IFE), simultaneously enhancing the distinct red emission of Eu3+ at 624 nm, a phenomenon attributed to the antenna effect (AE). This sensor demonstrates exceptional selectivity and sensitivity towards OTC, characterized by a linear detection range of 0.2–10 μM and a notably low detection limit of 2.21 nM. Furthermore, we achieved a visual semi-quantitative assessment of OTC through the discernible fluorescence color transition from blue to red under a 365 nm ultraviolet lamp. The practical applicability of this sensor was validated through the successful detection of OTC in milk and mutton samples, underscoring its potential as a robust tool for OTC monitoring in foodstuffs to safeguard food safety.

Blue fluorescent waterborne polyurethane‐based transition metal complexes with antibacterial activity

AbstractEfficient and stable blue fluorescent materials are the key components of light‐emitting devices and have received wide attention. Herein, transition metal complexes Zn(5‐AQ)2, Cu(5‐AQ)2, and Cd(5‐AQ)2 are prepared by using 5‐aminoquinoline (5‐AQ) as ligand and Zn2+, Cu2+, and Cd2+ as the central ions, respectively. Then, waterborne polyurethane (WPU)‐based transition metal complexes Zn(5‐AQ)2‐WPU, Cu(5‐AQ)2‐WPU, and Cd(5‐AQ)2‐WPU with different emission wavelengths of blue fluorescence are prepared by bonding Zn(5‐AQ)2, Cu(5‐AQ)2, and Cd(5‐AQ)2 to polyurethane chains as chain extenders, respectively. Noteworthily, with the increase of transition metal ion radius (Zn2+ < Cu2+ < Cd2+), the fluorescence emission wavelengths of the complexes showed different degrees of blue‐shift, and the blue‐shifted wavelengths showed a decreasing trend. Importantly, their fluorescence colors are blue‐shifted from blue‐green to blue with different emission wavelengths after accessing the polyurethane backbone, which has potential applications in the field of tuning white LED materials. The thermal decomposition temperatures of Zn(5‐AQ)2‐WPU, Cu(5‐AQ)2‐WPU, and Cd(5‐AQ)2‐WPU are above 220°C with good thermal stability, and their fluorescence lifetimes are prolonged by 8.817, 8.896, and 6.489 ns, respectively, compared with the complexes. Furthermore, WPU transition metal complexes with water as a dispersive medium have an antibacterial efficiency of up to 100% against Escherichia coli, which is an environmentally friendly antibacterial material with broad application prospects.

A BODIPY-Naphtholimine-BF2 Dyad for Precision Photodynamic Therapy, Targeting, and Dual Imaging of Endoplasmic Reticulum and Lipid Droplets in Cancer.

Currently, effective therapeutic modalities for pancreatic ductal adenocarcinoma (PDAC) are quite limited, leading to gloomy prognosis and ∼6-months median patient survival. Recent advances showed the promise of photodynamic therapy (PDT) for PDAC patients. Next generation photosensitizers (PS) are based on "organelle-targeted-PDT" and provide new paradigm in the field of precision medicines to address the current challenge for treating PDAC. In this investigation, we have constructed a novel PS, named as N b B, for precise and simultaneous targeting of endoplasmic reticulum (ER) and lipid droplets (LDs) in PDAC, based on the fact that malignant PDAC cells are heavily relying on ER for hormone synthesis. Our live cell imaging and fluorescence recovery after photobleaching (FRAP) experiments revealed that N b B is quickly targeted to ER and subsequently to LDs and shows simultaneous dual fluorescence color due to polar and nonpolar milieu of ER and LDs. Interestingly, the same molecule generates triplet state and singlet oxygen efficiently and causes robust ER stress and cellular lipid peroxidation, leading to apoptosis in two different PDAC cells in the presence of light. Together, we present, for the first time, a potential next generation precision medicine for ER-LD organelle specific imaging and PDT of pancreatic cancer.

A Strategy for Rapid Synthesis of Carbon Nanodots with Reversible Photoluminescence Switching for Sensitive Dynamic Anti‐Counterfeiting

AbstractCarbon nanodots (CDs) possess exceptional fluorescence properties, which have been extensively studied in the fields of fluorescence detection and anti‐counterfeiting information. However, the exploration of CDs with simple and fast synthesis paths, secure, and efficient encryption properties, remains a challenge. The rapid synthesis of orange CDs (O‐CDs) is reported with a high photoluminescence quantum yield (PLQY) of 57.6% within 10 min at atmospheric pressure using a one‐step pyrolysis method. The O‐CDs exhibit a dual‐emission property, with a blue emission peak at 425 nm and a strong orange emission peak at 590 nm. The dual‐emission peaks of O‐CDs can allow for fast orange/blue switching of fluorescence color with changes in the acid‐base environment. O‐CDs can serve as effective fluorescent probes for pH detection, depending on their fluorescence wavelength and intensity. Additionally, O‐CDs have potential for fluorescence anti‐counterfeiting. When exposed to NH3 gas, O‐CDs fluorescent ink rapidly (1 s) transitions from orange fluorescence to blue fluorescence, and then quickly (4 s) reverts back to orange fluorescence when the gas environment changes to HCl gas atmosphere. Thus, O‐CDs fluorescent inks offer several advantages, including high fluorescence intensity, fast response, recyclability, and lossless encryption/decryption in “on‐off‐on” double encryption anti‐counterfeiting.

Fluorescence sensing probe based on functionalized mesoporous MOFs for non-invasive and detection of dopamine in human fluids

Abnormal amount of dopamine (DA) in human body is closely relate to various diseases, such as Parkinson's disease, pheochromocytoma. Real-time monitoring DA is crucial for disease warning, diagnosis and treatment. Currently, most methods rely on invasive blood testing for detecting DA, which is only completed with the aid of the medical staffs in hospitals. Herein, a non-invasive fluorescence visual strategy is developed for the real-time monitoring DA, based on luminescent nanoparticles and modified mesoporous zeolite imidazole framework (ZIF-8-NH2) dodecahedrons. During the reaction process, DA is enriched through the spatial configuration of ZIF-8-NH2 and hydrogen bonding effect. The luminescence of Cr3+-doped zinc gallate (ZnGa2O4:Cr3+, ZGC) is inhibited by the photo-induced electron transfer (PET) mechanism to realize sensitively detecting DA. The intelligent sensing platform based on the designed fluorescence probe and color recognition system is structured for real-time detection of DA in urine. Furthermore, a skin-fitting hydrogel patch is prepared by combining a fluorescent probe with chitosan, which enables sensitive and accurate detection of DA in sweat without the complex sample pretreatment. The non-invasive fluorescence detection method provides an effective strategy for quantitatively monitoring DA in human fluids.

Enhanced security through dye-doped cholesteric liquid crystal shells for anti-counterfeiting

We explored the application of fluorescent dye doped Cholesteric Liquid Crystal (CLC) shells for anti-counterfeiting measures. These shells exhibit unique optical properties and, when infused with a fluorescent dye, produce a distinct fluorescent color upon exposure to UV light. We developed a microfluidic device using glass capillaries to generate uniform CLC shells. The shells were analyzed using a Polarizing Optical Microscope (POM) to study their defect structures. For anti-counterfeiting, QR code was encoded with CLC shells that were photopolymerized under ultraviolet light for enhanced durability. In daylight, the code reflects red and blue colors, but under UV light, it reveals the fluorescent dye color. This QR code can only be decrypted with UV illumination in both red and blue CLC shells. The color changes are easily visible to the naked eye, making this technique suitable for immediate verification. By utilizing this straightforward technique, security and chromic-based applications can be implemented with significantly increased cost-effectiveness and efficiency, surpassing the results of traditional approaches.

Comparison of characterization and composition of melanoidins from three different dried apple slices

The composition of melanoidins in dried apple that affects quality remains unclear. The composition and structure of melanoidins in dried apple slices by hot air drying (HAAM), instant controlled pressure drop drying (DICAM), and vacuum freeze-drying (FDAM) were investigated. It showed that the melanoidins were highly heterogeneous mixtures with a light-yellow color and blue-green fluorescence, belonging to polysaccharide-type melanoidins. Specifically, HAAM had a large molecular weight (929.5 g/mol) and wide molecular weight distribution, with more double-bond conjugated systems. DICAM (610.9 g/mol), possessing the strongest fluorescence intensity, was mainly composed of compounds with fewer π-conjugated structures and more electron-donating groups. As a control, the low level of Maillard reaction in FDAM resulted in the formation of the smallest molecular weight (458.6 g/mol) with weak fluorescence intensity. Moreover, 10 compounds were tentatively identified in apple melanoidins. This study provides the foundation for the future functional preparation of apple melanoidins.

The function and consequences of fluorescence in tetrapods

Fluorescence, the optical phenomenon whereby short-wavelength light is absorbed and emitted at longer wavelengths, has been widely described in aquatic habitats, in both invertebrates and fish. Recent years have seen a stream of articles reporting fluorescence, ranging from frogs, platypus, to even fully terrestrial organisms such as flying squirrels, often explicitly or implicitly linking the presence of fluorescence with sexual selection and communication. However, many of these studies fail to consider the physiological requirements of evolutionary stable signaling systems, the environmental dependence of perception, or the possible adaptive role of fluorescent coloration in a noncommunicative context. More importantly, the idea that fluorescence may simply constitute an indirect by-product of selection on other traits is often not explored. This is especially true for terrestrial systems where environmental light conditions are often not amenable for fluorescent signaling in contrast to, for example, aquatic habitats in which spectral properties of water promote functional roles for fluorescence. Despite the appeal of previously unknown ways in which coloration may drive evolution, the investigation of a putative role of fluorescence in communication must be tempered by a realistic understanding of its limitations. Here, we not only highlight and discuss the key body of literature but also address the potential pitfalls when reporting fluorescence and how to solve them. In addition, we propose exciting different research avenues to advance the field of tetrapod fluorescence.

Synthesis and Characterization of Multiple Stimuli-Responsive Fluorescent Polymer Hydrogels Based on Terpyridine and N-Isopropylacrylamide.

A series of stimuli-responsive fluorescent hydrogels were successfully synthesized via micelle radical copolymerization of hydrophilic acrylamide (AM), hydrophobic chromophore terpyridine-based monomer (TPY), and N-isopropylacrylamide (NIPAM). These hydrogels presented blue emissions (423-440 nm) under room temperature, which is caused by the π-π* transition of the conjugated structures. Once the ambient temperature was increased to 55 °C, the fluorescence color changed from blue (430 nm) to pink (575 nm) within 10 min, subsequently to yellow (535 nm), and eventually back to pink. The thermal-responsive properties are attributed to the transition of the TPY units from unimer to dimer aggregation via the intermolecular charge transfer complex at high temperatures. The hydrogels showed pH-responsive properties. The emission peak of the hydrogel exhibited a blue shift of ~54 nm from neuter conditions to acidic conditions, while a 6 nm red shift to an alkaline environment was observed. The hydrogels demonstrated an obvious change in fluorescence intensity and wavelength upon adding different metal ions, which is caused by the coordination between the terpyridine units incorporated on the backbones and the metal ions. As a consequence, the hydrogels presented a sharp quenching fluorescence interaction with Fe2+, Fe3+, Cu2+, Hg2+, Ni2+, and Co2+, while it exhibited an enhanced fluorescence intensity interaction with Sn2+, Cd2+, and Zn2+. The microstructural, mechanical, and rheological properties of these luminescent hydrogels have been systematically investigated.

Visual lambda-cyhalothrin detection using yellow carbon dots molecularly imprinted polyvinylidene fluoride fluorescent membrane

Due to its common use as an insecticide during agricultural production, residual lambda-cyhalothrin (LC) in food and the environment presents a significant human health risk. Developing an accurate LC detection method that does not require pretreatment remains a challenge. This study developed a novel yellow carbon dots molecularly imprinted (YCDs@MIPs) polyvinylidene fluoride (PVDF) composite (YCDs@MIPs@PVDF) fluorescent membrane for rapid visual LC detection. This method required no pretreatments during analysis since the LC could be specifically adsorbed when the samples passed through the YCDs@MIPs@PVDF membrane, causing fluorescence quenching, while matrix-interfering components could be removed for the porous structure of the membrane. A smartphone was used for rapid visual LC detection based on membrane fluorescence color changes in a dark-box ultraviolet analyzer. In food with a 15 % PVDF content and 6 mL added YCDs@MIPs, LC was quantitatively detected in a broad concentration range (5–500 μg/L) with a limit of detection (LOD) of 0.039 μg/L to 0.16 μg/L, which was lower than the strictest EU2019/92 limit of 10 μg/L. The analysis time was reduced from over 8 h when using the GB 23200.121–2021 and GB/T20769–2008 national standard methods to 30 min, while the analytical procedure decreased from six steps to two. The visual detection strategy combining the YCDs@MIPs@PVDF composite fluorescent membrane with a smartphone provided a new rapid detection technique for composite membrane purification and fluorescence signal output function.

Rapid detection and differentiation of chlortetracycline and tetracycline by N,P-Ti3C2 QDs

Ti3C2 QDs with good water solubility and photoluminescence properties was prepared by nitrogen and phosphorus doping (N,P-Ti3C2 QDs). The probe has a fluorescence emission peak at 420 nm and emits bright blue fluorescence, which can distinguish and detect two antibiotics with similar structures, chlortetracycline (CTC) and tetracycline (TC). The fluorescence enhancement effect can be realized by the interaction with CTC. The linear range is 2–22 μM, and the detection limit is as low as 0.53 μM. And the change of fluorescent color from bright blue to bright purple can be observed with the naked eye. At the same time, with the addition of TC, the fluorescence of N,P-Ti3C2 QDs can be quenched by static quenching effect, and the fluorescence color changes from bright blue to yellowish green. The detection range is 4.1–20.5 μM, and the detection limit is as low as 0.16 μM.Therefore, on this basis, a strategy for simultaneous detection and recognition of CTC and TC is proposed. The method has been successfully applied to the determination of CTC and TC in milk samples. This paper provides a new detection method for the identification of tetracycline antibiotics and taps the application potential of Ti3C2 QDs in food detection.