Simple design of fluorescein-based probe for rapid and in situ visual monitoring of histamine levels in food spoilage.

With the emergence of numerous food safety problems, rapid and accurate detection of histamine in food spoilage remains a challenge. To this end, we developed a simple design and easy synthesis of fluorescein-based probe FCHO to achieve specific and rapid (<1 s) quantitative detection of histamine through "imine formation" reaction. Significant enhanced fluorescence signal in response to histamine enabled our probe with high sensitivity as low as 51 nM. Utilizing the visualized fluorescence color changes of the probe as histamine increasing, we combined it with paper-based test chip to construct a color-resolved and highly selective recognition system. In addition, our proposed probe has been successfully used to visually imaging histamine changes in fish samples. Finally, for the first time, we have proved it possesses reliable ability to directly in situ imaging the distribution of histamine in whole spoiled fish. Thus, our strategy will provide great potential for monitoring food spoilage.

Preparation and application of achiral UiO-66-NH2 MOFs for enantioselective fluorescent detection of lysine enantiomers.

Lysine (Lys) is an essential nutrient that plays a crucial role in the growth and development of living organisms. Chiral analysis of Lys holds significant importance for ensuring the safety of food, pharmaceuticals, and health products. In this work, an achiral Zr-based metal organic frameworks (MOFs), UiO-66-NH2, was proposed as a fluorescent probe to achieve rapid response to l-lysine (L-Lys) in solution. Additionally, Zr4+ in the skeleton of UiO-66-NH2 framework exhibited different binding capacities towards Lys enantiomers, leading to distinct fluorescence responses for L-Lys and d-lysine (D-Lys). Leveraging these properties, the UiO-66-NH2 probe enabled accurate determination of L-Lys concentrations in solution, as well as the enantiomeric excess (ee) values of Lys solutions. Notably, in the detection of Lys enantiomers, the achiral UiO-66-NH2 acted as both a chiral selector and a fluorescent indicator, greatly improving the efficiency and stability of the detection system. The probable mechanism was further elucidated by pH titration experiments and density functional theory calculations. Additionally, the general applicability of this mechanism was validated by similar amino MOFs. The application of the UiO-66-NH2 fluorescent probe in analysis of infant formula milk powders and liquid milk samples confirmed the reliability of the method. Moreover, the construction of fluorescence test paper by immobilizing UiO-66-NH2 onto filler papers enabled the rapid identification of Lys enantiomers. Compared to previous fluorescent analyses of chiral amino acids assisted by additional metal ions, this study presented a novel approach and methodology that offers high efficiency, stability, reproducibility and reusability for the identification and detection of Lys enantiomers, highlighting the potential of the UiO-66-NH2 fluorescent probe in advancing analytical techniques.

A highly sensitive fluorescent probe based on functionalised ionic liquids for timely detection of trace Hg2+ and CH3Hg+ in food.

A novel fluorescent probe was fabricated using fluorescein-based ionic liquids (ILs) to effectively achieve rapid and accurate detection of Hg2+ and CH3Hg+ in food. A probe developed by addition of modified fluorescein into the functionalised ILs presented a promising sensitivity toward Hg2+ and CH3Hg+ at concentrations of 0.4 and 60 nM, respectively. In addition, the novel probe could achieve visual and timely detection of Hg2+ and CH3Hg+ by the naked eyes at concentrations of 0.1 and 1 µM, respectively. The probe could also overcome the interference of potential ions and common organic ligands and detect Hg2+ and CH3Hg+ in real food samples, such as green tea and liquor. The probe could be converted into a paper-based sensor to visually detect Hg2+ and CH3Hg+ at levels as low as 10 nM.

All-in-one spot test method for tetracycline using molecularly imprinted polymer-coated paper integrated into a portable 3D printed platform with smartphone-based fluorescent detection.

A molecularly imprinted polymer (MIP) has been synthetized, characterized, impregnated on paper, and integrated into a 3D printed platform with smartphone-based fluorescent detection for the determination of tetracycline in water samples. The MIP synthesis was performed by precipitation polymerization, which was subsequently deposited onto a glass microfiber paper. The synthesized polymer and the MIP@paper have been characterized by FTIR spectroscopy, scanning electron microscopy, and EDS spectroscopy. Afterward, a 3D printed detection platform that houses monochromatic LED strips as radiation source and a smartphone as detector have been used for determination of tetracycline. Digital image processing was based on the RGB colour model using image J software and the red intensity channel was used as analytical signal due to its higher sensitivity. Several factors that affect the adsorption capacity and fluorescent detection have been optimized. Under optimum conditions, detection limit of 0.04 mg L-1 and good linearity up 5 mg L-1 (r = 0.998), were achieved. The intra- and inter-day precision of 4.9 and 7.2 %, respectively, expressed as relative standard deviation (%RSD) were obtained, showing the good precision of the proposed methodology. Satisfactory recoveries between 87 and 98 % were obtained spiking real water sample matrices at different concentrations (0.1-0.3 mg L-1). The portable 3D platform with smartphone-based fluorescent detection exploiting all-in-one spot test method for tetracycline using MIP@paper was evaluated with AGREE and GAPI metrics, evidencing its environmentally friendly approach. Furthermore, the BAGI tool demonstrated the practicality of the method, in terms of functionality and applicability compared to previous HPLC and spectrofluorometric methods.

Ionophore-based nanospheres enable selective and sensitive fluorescence detection of copper ions.

A novel ionophore-based fluorescent nanosensor has been successfully fabricated for the sensitive and selective detection of Cu2+ ions. The nanosensor was constructed through self-assembly of amphiphilic block copolymers, incorporating elesclomol as a Cu2+ ionophore and long-chain dialkylcarbocyanines (DiD) as a fluorescent dye. This design exhibits an "ON/OFF" fluorescence response, where Cu2⁺ ions are selectively sequestered within the nanosensors, resulting in fluorescence quenching of DiD. This strategy enables rapid and highly selective Cu2⁺ sensing with remarkable fluorescence quenching efficiency (up to 93.5 %) and an exceptionally low detection limit of 28.6 nM. The linear detection range extends over two orders of magnitude (0.05-10 µM). Furthermore, the feasibility of this nanosensor for practical applications was confirmed through successful determination of Cu2+ in real water and beer samples, with excellent recovery rates. This nanosensor offers advantages of simplicity, rapidity, and cost-effectiveness, holding significant potential for sensitive and selective Cu2+ detection in various biological and environmental samples.

Ultrahigh-sensitivity vinyl-COF fluorescent sensor for trace organic arsenic detection.

Recently, the misuse of organic arsenic feed additives, such as roxarsone (ROX), has increasingly jeopardized both human health and the environment. In response, a unique electron-rich pyrazine-cored fluorescent covalent organic framework (COF) nanosheet, named as COF-TMP, was synthesized using an alkali-catalyzed reaction between 2, 3, 5, 6-tetramethylpyrazine (TMP) and terephthalaldehyde (TPA). Characterization demonstrated that COF-TMP boasted high porosity, pronounced fluorescence, and an abundance of (E)-2-styrylpyrazine (SPA) groups. These attributes render it an exceptional fluorescent sensor for the ultrahigh sensitivity detection of electron-deficient ROX molecules. The limit of detection (LOD) for COF-TMP in detecting ROX was found to be 0.015 ppb through fluorescence-quenching titration experiments-surpassing all previously reported fluorescent sensors. A combination of experimental results and theoretical calculations suggests that the extraordinary detection capability of COF-TMP for ROX arises from a static quenching mechanism. This study paves the way not only for a novel pyrazine-based fluorescent COF nanosheet with high porosity, exceptional fluorescent capabilities, and abundant SPA groups suitable for highly sensitive and selective ROX detection but also hints at its potential application as a fluorescent sensor for environmental pollution management and related domains.

Oriented surface imprinting of epitopes anchored on silica nanoparticles containing quantum dots by thiol-disulfide exchange reactions for the enhanced fluorescence detection of proteins.

As artificial receptors for protein recognition, epitope-imprinted polymers combined with fluorescence sensing based on quantum dots (QDs) can be potentially used for biological analysis and disease diagnosis. However, the usual way for fabrication of QD sensors through unoriented epitope imprinting is confronted with the problems of disordered imprinting sites and low template utilization. In this context, a facile and efficient oriented epitope surface imprinting was put forward based on immobilization of the epitope templates via thiol-disulfide exchange reactions. With N-succinimidyl 3-(2-pyridyldithio)-propionate (SPDP) as a heterobifunctional reagent, cysteine-modified epitopes of cytochrome c were anchored on the surface of pyridyl disulfide functionalized silica nanoparticles sandwiching CdTe QDs. After surface imprinting via a sol-gel process, the epitope templates were removed from the surface-imprinted layers simply by reduction of the thiol-disulfide, affording oriented epitope-imprinted sites. By this method, the amount of epitope templates was only 1/20 of traditionally unoriented epitopes. The resulting sensors demonstrated significantly enhanced imprinting performance and high sensitivity, with the imprinting factor increasing from 2.6 to 3.9, and the limit of detection being 91 nM. Such epitope-oriented surface-imprinted method may offer a new design strategy for the construction of high-affinity protein recognition nanomaterials with fluorescence sensing.

Zwitterionic polymers grafting of metal organic framework encapsulated boronic acid carbon dots as antibiofouling fluorescent probe for baicalin monitoring.

The sensitivity and accuracy of fluorescence probes for biological samples are affected by not only interfering molecule compounds but also the nonspecific adsorption of proteins and other macromolecules. Herein, fluorescence probe based on zwitterionic sulfobetaine methacrylate polymer (PSBMA) as an antibiofouling layer and amino boric acid carbon dots encapsulated in the metal-organic framework UiO-66-NH2 (UiO-66-NH2/BN-CDs) as a target recognition site was designed for the detection of baicalin (BAI). Owing to the introduction of BN-CDs into UiO-66-NH2 with high specific surface area, the prepared UiO-66-NH2/BN-CDs@PSBMA probe exhibited a high adsorption capacity of 78.9 mg g-1, while presented fluorescence enhancing and superior fluorescence selectivity to BAI at excitation and emission wavelengths of 400 and 425 nm, respectively. Connecting PSBMA with good hydrophilicity to UiO-66-NH2, resulted in an anti-protein capacity of over 96.3 %, effectively inhibiting protein interference with the fluorescence signal. By virtue of its good antibiofouling and recognizing capacities, the fluorescence probe exhibited a satisfactory detection range of 10-80 nmol L-1, with a fairly low detection limit of 0.0064 µmol L-1. Using the method to detect BAI in Goji berry, Sophora and Yinhuang oral solution, demonstrating its potential for the accurate and quantitative detection of BAI in complex biological samples.

A universal fluorescence biosensor based on rolling circle amplification and locking probe for DNA detection.

A stable DNA signal amplification sensor was developed on account of rolling circle amplification (RCA). This sensor includes target DNA-controlled rolling circle amplification technology and locking probe DNA replacement technology, which can be used to detect DNA fragments with genetic information, thus constructing a biosensor for universal detection of DNA. This study takes the homologous DNA of human immunodeficiency virus (HIV) and let-7a as examples to describe this biosensor. The padlock probe is first cyclized by T4 DNA ligase in response to the target's reaction with it. Then, rolling cycle amplification is initiated by Phi29 DNA polymerase, resulting in the formation of a lengthy chain with several triggers. These triggers can open the locked probe LP1 with the fluorescence signal turned off, so that it can continue to react with H2 to form a stable H1-H2 double strand. This regulates the distance between B-DNA modified by the quenching group and H1 modified by fluorescent group, and the fluorescence signal is recovered.

Modified glove removal technique to prevent hand contamination in routine phlebotomy.

The World Health Organization and the Centers for Disease Control and Prevention (CDC) have established guidelines recommending the performance of hand hygiene routines for healthcare workers following glove removal. However, the completion of frequent hygiene routines can cause allergic and adverse skin reactions. This double-blind, randomized study aimed to address this concern by developing and evaluating a modified glove removal technique that minimizes contamination risk during routine phlebotomy procedures. Furthermore, this study used fluorescent detection to compare the frequency of contamination associated with the CDC-recommended technique and the modified technique using fluorescent detection. One hundred healthcare personnel were enrolled and divided into two groups: one group followed the CDC technique, while the other group implemented the modified technique. Participants received instructional videos and practiced under supervision. They subsequently performed blood collection using a simulation arm covered with fluorescent cream as a contamination marker. After removing gloves, hand contamination was assessed under a black light. The median time required for glove removal in the modified group was four seconds longer than that in the group that followed the CDC technique (p < 0.001). Contamination was observed in 2% (1/50) of subjects using the CDC-recommended technique, while no contamination was detected with the modified technique (p ≥ 0.05). Both the group that followed the CDC technique and the group that used modified glove removal techniques demonstrated the potential to prevent contamination during phlebotomy, thereby reducing the need for hand hygiene and the occurrence of contamination and adverse skin reactions. These findings prompt further exploration into whether proper glove removal can reduce the frequency of completing a hand hygiene routine after each glove removal, specifically within the context of phlebotomy. However, it is essential to note that hand hygiene following glove removal is still recommended to prevent contamination. Further research is warranted to validate these findings.

Turn-on Coumarin Precursor: From Hydrazine Sensor to Covalent Inhibition and Fluorescence Detection of Rabbit Muscle Aldolase.

Hydrazine, a highly toxic compound, demands sensitive and selective detection methods. Building upon our previous studies with pre-coumarin OFF-ON sensors for fluoride anions, we extended our strategy to hydrazine sensing by adapting phenol protecting groups (propionate, levulinate, and γ-bromobutanoate) to our pre-coumarin scaffold. These probes reacted with hydrazine, yielding a fluorescent signal with low micromolar limits of detection. Mechanistic studies revealed that hydrazine deprotection may be outperformed by a retro-Knoevenagel reaction, where hydrazine acts as a nucleophile and a base yielding a fluorescent diimide compound (6,6'-((1E,1'E)-hydrazine-1,2diylidenebis(methaneylylidene))bis(3(diethylamino)phenol, 7). Additionally, our pre-coumarins unexpectedly reacted with primary amines, generating a fluorescent signal corresponding to phenol deprotection followed by cyclization and coumarin formation. The potential of compound 3 as a theranostic Turn-On coumarin precursor was also explored. We propose that its reaction with ALDOA produced a γ-lactam, blocking the catalytic nucleophilic amine in the enzyme's binding site. The cleavage of the ester group in compound 3 induced the formation of fluorescent coumarin 4. This fluorescent signal was proportional to ALDOA concentration, demonstrating the potential of compound 3 for future theranostic studies in vivo.

Polymerization-induced emission and selective detection to Fe3+/ Fe2+ of triazine-containing polyureas.

In this study, four polyureas with triazine moiety (PUAs) were successfully synthesized through the polymerization of triazine-containing diamine and diisocyanate. The intramolecular aggregation of triazine rings and urea groups along the macromolecular backbone gives PUAs a significant polymerization-induced emission (PIE). Among the four PUAs, PUA-LP shows a significant fluorescent emission at 450 nm, compared to non/weak fluorescent 2,4-diamino-6-phenyl-1,3,5-triazine and L-Lysine diisocyanate ethyl ester monomers. Additionally, the external factors such as solution concentration, excitation wavelength, and precipitants also play a crucial role in the fluorescence of PUAs. As expected, PUA-LP can selectively recognize and detect Fe3+/Fe2+ ions even in the presence of 12 other metal ions and 10 anions. The limit of detection of PUA-LP to Fe3+/Fe2+ is as low as 1.02 µM (0.06 mg/L) and 0.86 µM (0.05 mg/L), respectively, and far below 0.3 mg/L of the allowable national standard for drinking water by WHO. Furthermore, the quenching mechanism of Fe3+/Fe2+ to PUA-LP is attributed to static quenching caused by the coordination of Fe3+/Fe2+ ions with a coordination ratio of 2:1. Based on PIE, the fluorescent PUA-LP was made into an observable and portable testing paper for detecting Fe3+/Fe2+ ions. Finally, we measured the recovery rate of the actual tap water samples and compared the performance of PIE-active PUA-LP with the other reported fluorescent probes to Fe3+/Fe2+ ions.

A novel dual-channel cassava starch/polyvinyl alcohol-based film for visual monitoring of shrimp freshness.

In this study, the polyvinylpyrrolidone-alizarin nanoparticles (PVP-AZ NPs) with favorable water dispersion and the carbon quantum dots (RQDs) with aggregate induced emission effect were synthesized to construct an eco-friendly film for food freshness monitoring. The introduction of PVP-AZ NPs and RQDs enhanced the network structure and thermal stability of the cassava starch/polyvinyl alcohol film, and reduced its crystallinity and light transmittance via non-covalent binding with the film-forming matrix. The developed film exhibited visually recognizable colorimetric and fluorescent responses to ammonia at 0.025-25 mg/mL, and it can be reused at least 6 times. Practical application experiment proved that the film, as an indicator label, can achieve accurate, real-time, and visual dynamic monitoring of the freshness of shrimp stored at 25 °C, 4 °C, and - 20 °C under daylight (orange yellow to purple) and UV light (red to blue). The integration of multivariate detection technology can eliminate the interference of external factors by self-correction to improve sensitivity and reliability, which provides a reference for the development of other food quality and safety monitoring platforms.

A pump-free paper/PDMS hybrid microfluidic chip for bacteria enrichment and fast detection.

Developing portable and sensitive biosensors for bacteria detection is highly demanded due to their association with environmental and food safety. Paper-based microfluidic chip is the suitable candidate for constructing pump-free biosensor since paper is hydrophilic, low-cost and easy to use. However, the contradiction between sensitivity and small sample volume seriously affects the application of paper-based chip for bacteria detection. Here, a new microfluidic biosensor, combining large PDMS reservoir for sample storage, hydrophilic paper substrate for pump-free water transport, coated microspheres for bacteria capture and super absorbent resin for water absorption, is designed for the detection of bacteria in aqueous samples. Once the sample solution is introduced in the reservoir, water will automatically flow through the gaps between microspheres and the target bacteria will be captured by the aptamer coated on the surface. To facilitate PDMS reservoir bonding and ensure water transport, the upper side of paper substrate is coated with Polyethylenimine modified PDMS and the bottom side is kept unchanged. After all the solution is filtrated, fluorescent dye strained bacteria are enriched on the microspheres. The fluorescent intensity representing the number of bacteria captured is then measured using a portable instrument. Through the designed microfluidic biosensor, the bacteria detection can be achieved with 2 mL sample solution in less than 15 min for water or 20 min for diluted milk. A linear range from 10 CFU/mL to 1000 CFU/mL is obtained. The paper-based 3D biosensor has the merits of low-cost, simple operation, pump-free and high sensitivity and it can be applied to the simultaneous detection of multiple bacteria via integrating different aptamers.

Comparative analysis of Herceptin N-Linked glycosylation by HILIC-FLD and LC-MS/MS methods.

Monoclonal antibodies like Herceptin play a pivotal role in modern therapeutics, with their glycosylation patterns significantly influencing their bioactivity. To characterize the N-glycan profile and their relative abundance in Herceptin, we employed two analytical methods: hydrophilic interaction chromatography with fluorescence detection (HILIC-FLD) for released glycans and liquid chromatography tandem mass spectrometry (LC-MS/MS) for glycopeptides. Our analysis included 21 European Union (EU)-Herceptin lots and 14 United States (US)-Herceptin lots. HILIC-FLD detected 25 glycan species, including positional isomers, revealing comparable chromatographic profiles for both EU and US lots. On the other hand, LC-MS/MS identified 26 glycoforms within the glycopeptide EEQYNSTYR. Both methods showed that a subset of glycans dominated the total abundance. Notably, EU-Herceptin lots with an expiration date of October 2022 exhibited increased levels of afucosylated and high mannose N-glycans. Our statistical comparisons showed that the difference in quantitative results between HILIC-FLD and LC-MS/MS is significant, indicating that the absolute quantitative values depend on the choice of the analytical method. However, despite these differences, both methods demonstrated a strong correlation in relative glycan proportions. This study contributes to the comprehensive analysis of Herceptin's glycosylation, offering insights into the influence of analytical methods on glycan quantification and providing valuable information for the biopharmaceutical industry.

Design and synthesis of pyrene-based probes and their fluorescent detection of Sb(III).

A series of pyrene-based fluorescent (FL) probes for Sb(III) were designed and synthesized. All of them exhibited luminescence by pyrene excimers in the mixture of DMSO and water and showed enhanced emission with the addition of Sb(III). By comparing their FL response to Sb(III), the effects of intramolecular hydrogen bond, inductive effect, and steric effect were investigated. Meanwhile, the FL enhancement factor of the best performing probe reached 10.28 and the detection limit was calculated to be 0.0535 mg/L, indicating that it might be used as a potential candidate for the treatment of Sb(III) in printing and dyeing wastewater.

A zwitterionic probe for ratiometric fluorescent detection of aluminium(III) ion in aqueous medium and its application in bioimaging.

In the present study, we have synthesized an aminobenzoic acid containing Schiff base (compound 1) and its structure was confirmed through single crystal X-ray study. Importantly, the compound 1 crystallizes in the zwitterionic form, with an anionic carboxylate group (-COO-) and a cationic iminium group (-C = NH+-). The compound 1 is highly soluble in water due to its zwitterionic feature in the solid state. Interestingly, compound 1 acts as a ratiometric fluorescent probe for the selective detection of Al3+ ion in aqueous solution without organic cosolvent. It can also detect Al3+ ion by visual colour change to bluish-green fluorescence under 365 nm UV light. The association constant between compound 1 with Al3+ ion was estimated to be 1.67 × 104 M-1. The lowest detection limit for Al3+ ion was calculated to be 7.05 × 10-8 M in water. Compound 1 in combination with Al3+ ion demonstrated fluorescent imaging potential of the nucleus of in RAW 264.7 murine macrophage cell line. In addition, the sensing model is developed as paper based sensor ''Test Kit' 'for its practical applicability.

Rapid and sensitive detection of large yellow croaker iridovirus by real-time RPA and RPA-LFD.

Large yellow croaker (Larimichthys crocea) is a vital marine-cultured species in China. Large yellow croaker iridovirus (LYCIV) can cause a high mortality rate in L. crocea. Rapid and convenient detection of LYCIV is an urgent demand for diagnosis. In this study, rapid and simple recombinase polymerase amplification (RPA), real-time RPA and RPA combined with lateral flow dipstick (RPA-LFD) methods were developed for the detection of LYCIV based on the conserved sequence of the LYCIV major capsid protein (MCP) gene. With these optimized RPA analyses, LYCIV detection could be completed within 20 min at 40°C. Both RPA and real-time RPA could detect viral DNA as low as 102 copies/µL, while the detection limit of RPA-LFD was 101 copies/µL, and there was no cross-reaction with other aquatic pathogens (KHV, CyHV-2, GCRV-JX01, SVCV, LCDV and LMBV). In practical evaluation of RPA, real-time RPA and RPA-LFD methods, the results showed consistency with the general PCR detection. In short, the developed RPA, real-time RPA and RPA-LFD analyses could be simple, rapid, sensitive and reliable methods for field diagnosis of LYCIV infection and have significant potential in the protection of LYCIV infection.

Nanomaterials for Fluorescent Detection of Hemoglobin.

Hemoglobin plays a vital role in a series of biological activities. Abnormal levels of hemoglobin in blood are associated with many clinical diseases. Therefore, development of simple and accurate methods for sensing hemoglobin is of considerable significance. The blowout advancement in nanotechnology has urged the use of different types of fluorescent nanomaterials for hemoglobin assay. The past decades have witnessed the rapid progress of fluorescent nanosensors for hemoglobin assay. In the review, the sensing principles of fluorescent nanomaterials for sensing hemoglobin were briefly discussed. The advances of fluorescent nanosensors for detection of hemoglobin were further highlighted. And the sensing performance of fluorescent nanosensors versus traditional detection approaches was compared. Finally, the challenges and future directions of fluorescent nanomaterials for detection of hemoglobin are discussed. The review will arouse much more attention to the construction of hemoglobin sensors and facilitate rapid development of fluorescent nanosensors of hemoglobin.

Dual-emissive Eu(III)-functionalized metal-organic frameworks for visual, rapid, and intelligent sensing of albendazole and albendazole sulfoxide in animal-origin food.

Albendazole (ABZ), a benzimidazole-based anthelmintic, is widely used to treat helminth infections. The extensive and improper use of ABZ may cause drug residues in animal-origin food and anthelmintics resistance, which potentially threaten human health. Meanwhile, albendazole sulfoxide (ABZSO), a metabolite of ABZ, also exhibits toxic effects. Therefore, the detection of ABZ and ABZSO in animal-derived food is significantly necessary. Herein, a dual-emission europium fluorescent sensor (EuUHC-30) was rationally designed and constructed. EuUHC-30 exhibits high selectivity and sensitivity towards ABZ and ABZSO with a detection limit of 0.10 and 0.13 µM, respectively. Furthermore, EuUHC-30 was successfully applied for quantification of ABZ and ABZSO in milk and pig kidney, which were verified by HPLC analysis. Moreover, a smartphone-assisted EuUHC-30 fluorescent paper sensor was fabricated for the practical determination of ABZ and ABZSO in real food. Overall, this work provides a visual, rapid, and intelligent method for the detection of ABZ and ABZSO in animal-origin food.