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The ability of anuran larvae to efficiently locate food is essential for their growth and development, but little is known about the sensory modalities they use to find food. We experimentally assessed the role of visual and chemical cues in finding food in tadpoles of the invasive species Lithobates catesbeianus. In the two‐choice experiment, using rectangular containers that offer visual and/or chemical food cues on opposite ends, tadpoles chose the side where the chemical cues of the food were present consistently. The visual cues alone showed an initial transient attraction of tadpoles, which disappeared after a few minutes, suggesting that tadpoles are potentially capable of seeing contrasting objects, at least, at a close range and in clear waters and daylight conditions. We also evaluated the foraging behaviour and the capability of tadpoles to find food in an open field experiment under two different lighting conditions: natural daylight and darkness. Results showed that tadpoles find food faster in dark conditions, confirming that chemical cues alone are sufficient for tadpoles of this species to find food. Moreover, the time spent feeding and the number of tadpoles simultaneously exploiting the food patch were greater in darkness suggesting that environments with low visibility conditions could favour the establishment of L. catesbeianus. Understanding the sensory modalities used by tadpoles of this invasive species to find food could help to understand the potential abilities to expand and establish in novel environments. [ABSTRACT FROM AUTHOR]

Food is closely related to human life. With the development of the times, the human demand for food has changed dramatically. People pay closer attention to the safety, health, composition, brand, origin, and processing method of food, which is precisely inseparable from food testing technology. Currently, there are many food inspection technologies, and the electronic nose (E-nose), as an efficient, fast, non-destructive, and promising technology, has been successfully applied in many aspects of the food industry and has shown promising results. This paper first introduces the basic principle and composition of the E-nose. Then it describes in detail the key elements, including gas sensor selection, sampling method design, data acquisition and information processing. Further summarizes the various typical applications of E-nose technology in the food industry in recent years, including six application directions: freshness assessment, process monitoring, flavor evaluation, authenticity evaluation, quality control, origin traceability and pesticide residue detection. Finally, the critical problems that need to be solved in the current application of E-nose technology in the food industry are discussed, and the potential future research directions in this field are foreseen. [ABSTRACT FROM AUTHOR]

From farm to plate, food meets various challenges and pollution. Food detection is essential to ensure food safety. Although detection techniques have obtained great development, the accuracy, sensitivity and operating conditions still have room for improvement. Composed of dielectric media with different refractive indices to form a periodic structure, an optical material named photonic crystal (PC) can offer a breakthrough. Owing to the periodic structure, Bragg diffraction happens with optical waves propagating in a PC and photonic band gap (PBG), a characteristic parameter of the PC, will form. The properties of PBG are widely used in the field of detection. Combined with the techniques of biology, immunology, optics and fluorescence etc., PCs can play the role of specific, efficient, sensitive and convenient sensors in food detection. At present, PCs have been successfully applied to analyze hazardous substances in food, such as microorganisms, biotoxins, veterinary drug residues, pesticide residues, excessive additives, illegal additives, environmental pollutants and heavy metal composition. This article introduces PCs about the fabrication methods, principles and techniques applied in detection and research progress in food detection. [ABSTRACT FROM AUTHOR]

In recent years, developing rapid, simple, and effective new methods to monitor food safety is standing out enough to be noticed. Electrospinning is an easy, versatile, and low-cost technique to fabricate multifunctional micro-and nanomaterials. The combination of electrospinning and biosensors is one of the most promising strategies and is expected to replace traditional detection materials. This paper reviews the research progress of electrospinning in food detection, including electrospinning materials generally used in the food field with their benefits of high aspect ratio, large specific surface area, tunable porosity, easy functionalization, easy handling, mechanical stability, such as natural polymers, synthetic polymers or the mixture of both. Besides, we also emphatically introduced the application of their intrinsic characteristics combined with biosensing platforms and list the sensitivity and detection limit of various methods and materials in detection, as well as their application potential, and the challenges faced by the on-site detection and the large-scale commercial applications in the food industry as future exploration headings, giving new thinking of nanomaterial applications for food safety detection. [ABSTRACT FROM AUTHOR]

Automatic food classification systems have several interesting applications ranging from detecting eating habits, to waste food management and advertisement. When a food image has multiple food items, the food detection step is necessary before classification. This work challenges the food detection issue and it introduces to the research community the Segmented UEC Food-100 dataset, which expands the original UEC Food-100 database with segmentation masks. In the semantic segmentation experiment, the performance of YOLAC and DeeplabV3+ has been compared and YOLAC reached the best accuracy of 64.63% mIoU. In the instance segmentation experiment, YOLACT has been used due to its speed and high accuracy. The benchmark performance on the newly released Segmented UEC Food-100 dataset is 68.83% mAP. For comparison purpose, experiments have been run also on the UEC FoodPix Complete dataset of Okamoto et al. The database and the code will be available after publication. [ABSTRACT FROM AUTHOR]

Bacteroides dorei is a promising candidate for the next-generation probiotics (NGP), but its accurate identification remains challenging due to its close taxonomic relationship with other Bacteroides species. This study aimed to mine the novel specific molecular target for detecting Bacteroides dorei. Using pan-genome analysis and PCR validation, species-specific target genes with a size of 193 bp were identified, and the specificity of the designed primer pair (30 bp) for this molecular target was confirmed. The PCR assay demonstrated high applicability for detecting target and/or nontarget strains in three simulated food systems, yielding no false-positive or false-negative results. Additionally, a qPCR method was developed for quantifying Bacteroides dorei , with a linear detection range from 1 × 108 to 1 × 101 CFU/mL and an R2 value greater than 0.98. This method exhibited accurate and sensitive detection capabilities suitable for both food and feces samples. Overall, our study established PCR and qPCR assays for the rapid identification of Bacteroides dorei , advancing the exploration of Bacteroides species and the application of detection for NGPs in functional foods across various product forms. [Display omitted] • New species-specific molecular target for Bacteroides dorei was identified. • PCR assay were developed for rapid identification of Bacteroides dorei. • qPCR assay were established for sensitive quantification of Bacteroides dorei. • These assays showed applicability for detecting in simulated or food samples. [ABSTRACT FROM AUTHOR]

Nitrite (NO 2 −) is present in a variety of foods, but the excessive intake of NO 2 − can indirectly lead to carcinogenic, teratogenic, mutagenicity and other risks to the human body. Therefore, the detection of NO 2 − is crucial for maintaining human health. In this study, an integrated array sensor for NO 2 − detection is developed based on molybdenum single atom material (IMS Mo-SAC) using high-resolution electrohydrodynamic (EHD) printing technology. The sensor comprises three components: a printed electrode array, multichannels designed on polydimethylsiloxane (PDMS) and an electronic signal process device with bluetooth. By utilizing Mo-SAC to facilitate electron transfer during the redox reaction, rapid and efficient detection of NO 2 − can be achieved. The sensor has a wide linear range of 0.1 μM–107.8 mM, a low detection limit of 33 nM and a high sensitivity of 0.637 mA−1mM−1 cm−2. Furthermore, employing this portable array sensor allows simultaneously measurements of NO 2 − concentrations in six different foods samples with acceptable recovery rates. This array sensor holds great potential for detecting of small molecules in various fields. [ABSTRACT FROM AUTHOR]

Carbon quantum dots (CQDs) are category of novel carbon nanomaterials, which have gradually attracted attention due to their unique properties. CQDs have obvious advantages such as water solubility, modifiability, photochemical property, easy surface modification, antibacterial activity and good biocompatibility. In this paper, the formation mechanism and doping synthesis methods of CQDs are summarized. This review also highlights the biological toxicity, antibacterial properties and application of CQDs in the detection of heavy metals, antibiotics, pathogens, pesticide residues and prohibited additives in food, nutritional functional components, and fresh-keeping of fruits and vegetables. [ABSTRACT FROM AUTHOR]

Raman spectroscopy is a type of scattering spectroscopy with features such as rapid, less susceptible to moisture inter‐ ference, no sample pre-treatment and in vivo detection. As a powerful characterization tool for analyzing and testing the molecu‐ lar composition and structure of substances, Raman spectroscopy is also playing an extremely important role in the detection of plant and animal phenotypes, food safety, soil and water quality in the agricultural field with the continuous improvement of Ra‐ man spectroscopy technology. In this paper, the detection principles of Raman spectroscopy are introduced, and the new pro‐ gresses of eight Raman spectroscopy technology are summarized, including confocal microscopy Raman spectroscopy, Fourier transform Raman spectroscopy, surface-enhanced Raman spectroscopy, tip-enhanced Raman spectroscopy, resonance Raman spectroscopy, spatially shifted Raman spectroscopy, frequency-shifted excitation Raman difference spectroscopy and Raman spectroscopy based on nonlinear optics, etc. And their advantages and disadvantages and application scenarios are prerented, re‐ spectively. The applications of Raman spectroscopy in plant detection, soil detection, water quality detection, food detection, etc. are summarized. It can be specifically subdivided into plant phenotype, plant stress, soil pesticide residue detection, soil col‐ ony detection, soil nutrient detection, food pesticide detection, food quality detection, food adulteration detection, and water quality detection. In future agricultural applications, the elimination of fluorescence background due to complex living organ‐ isms in Raman spectroscopy is the next research direction. The study of stable enhanced substrates is an important direction in the application of Surface Enhanced Raman Spectroscopy (SERS). In order to meet the measurement of different scenarios, por‐ table and telemetric Raman spectrometers will also play an important role in the future. Raman spectroscopy needs to be further explored for a wide variety of research objects in agriculture, especially for applications in animal science, for which there is still a paucity of relevant studies up to now. In the existing field of agricultural research, it is necessary to pursue the character‐ ization of more specific substances by Raman spectroscopy, which can prompt the application of Raman spectroscopy for a wid‐ er range of uses in agriculture. Further, the pursuit of lower detection limits and higher stability for practical applications is also the direction of development of Raman spectroscopy in the field of agriculture. Finally, the challenges that need to be solved and the future development directions of Raman spectroscopy are proposed in the field of agriculture in order to bring more in‐ spiration to future agricultural production and research. [ABSTRACT FROM AUTHOR]

Monitoring food quality throughout the food supply chain is critical to ensuring global food safety and minimizing food losses. Here we find that simply by mixing an aqueous solution of sugar-stabilized Ag+ and amines in an open vessel leads to the generation of Ag NPs and an intelligent evaluation system based on a colorimetric Ag+ probe is developed for real-time visual monitoring of food freshness. The self-assembly reaction between methylamine (MA) generated during meat storage and the colorimetric Ag+ probe produces different color changes that indicate changes in the quality of the meat. The colorimetric Ag+ probe was integrated into food packaging systems for real-time monitoring of chilled broiler meat freshness. The proposed evaluation system provides a versatile approach for detecting biogenic amines and monitoring chilled broiler meat freshness and it has the advantages of high selectivity, real-time and on-site measurements, sensitivity, economy, and safety and holds great public health significance. [ABSTRACT FROM AUTHOR]

Hypochloric acid (HClO) is a reactive oxygen species (ROS) that functions as a bacteriostatic and disinfectant in food production. Excessive levels of ClO−, however, have been linked to various health issues, including cardiovascular diseases (Halliwell and Gutteridge in Oxford University press, USA, 2015), arthritis, and neurodegenerative diseases (Heinzelmann and Bauer in Biol Chem. 391(6):675–693, 2010). Therefore, synthesizing highly selective and sensitive probes for rapidly detecting endogenous ClO− in daily foods is currently a popular research topic (Kalyanaraman et al. in Redox Biol. 15:347–362, 2018; Winterbourn in Nat Chem Biol. 4(5):278–286, 2008; Turrens in J Physiol. 552(2):335–344, 2003). Thus, we have developed two highly selective ratiometric fluorescent probes (Probe1 and Probe2) based on indole-phenothiazine to detect ClO− in common vegetables, fruits and beverages qualitatively and quantitatively. Moreover, Both Probe1 and Probe2 have shown good specificity and stability, with high fluorescence intensity and long duration (Feng et al. in Adv Sci. 5:1800397, 2018; Wei et al. in Angew Chem. 131(14):4595–4599, 2019; Baruah et al. in J Mater Chem B, 2022). [ABSTRACT FROM AUTHOR]

[Display omitted] • 3a and 3c are screened out from five D-A type dicyanoisophorone derivatives, which show high selectivity towards H 2 O 2. • 3a and 3c express colorimetric and fluorescent dual-signals towards H 2 O 2 with low detection limits (0.20 μM and 0.14 μM). • 3a and 3c are capable of H 2 O 2 detection in milk samples. • Low cytotoxicity allows 3a to be utilized as a H 2 O 2 fluorescence sensor in living HepG-2 cells and zebrafish. • A smartphone-based analysis method is utilized for the rapid quantitative detection of H 2 O 2 by 3c. Excessive residual hydrogen peroxide (H 2 O 2) disinfectant in food is harmful to human health. Therefore, it is necessary to develop efficient detection methods for H 2 O 2 detection. In this work, we designed and synthesized five D-A molecules 3a - 3e by introducing electron-donor substituents (–OCH 3 and –CH 3) to the electron-acceptor dicyanoisophorone skeleton in order to find out the suitable probes for H 2 O 2 detection. Among them, two promising probes, 3a and 3c , are screened out according to structure-property relationships. Based on the principle of intramolecular charge transfer (ICT), 3a and 3c express colorimetric and fluorescent dual-signals towards H 2 O 2 with low detection limits (0.20 μM and 0.14 μM) and rapid response (within 20 mins). The reaction mechanism between probes and H 2 O 2 is determined by 1H NMR and HRMS. Density functional theory (DFT) calculations are measured to study the regulation mechanism of structure adjustment on probs performance. Furthermore, a smartphone RGB analysis is utilized as a portable platform for the quantitative detection of H 2 O 2 without complicated instruments, indicating a high efficiency and on-site detection method for H 2 O 2. In addition, probes are applied to detect H 2 O 2 in milk samples, HepG-2 cells and zebrafish, suggesting the promising applications in food samples and physiological systems. [ABSTRACT FROM AUTHOR]

• An Ag-coated nanofiber SERS platform was prepared for rapid nitrite detection. • Electrospraying technique was firstly used to assemble SERS platform. • The Ag-coated nanofiber SERS platform has good homogeneity and reproducibility. • The EF and the LOD was 2.635 × 108, 2.216 × 10−12 M, respectively. • The SERS platform shows good compatibility in nitrite detection for real samples. Nitrite is commonly used as a preservative and color fixative in the meat industry. However, the risk of it transforming into N -nitrosamine restricts its intake. Herein, a novel sensitive Ag-coated nanofiber surface-enhanced Raman scattering (SERS) platform was developed for rapid nitrite detection. The electrospraying technique was firstly used to assemble Ag nanoparticles (NPs) on the nanofibers to obtaine SERS platform. The homogeneity and long-term stability of the SERS platform were evaluated. The limit of detection (LOD) of the SERS platform was estimated to be 2.216 × 10−12 mol/L, corresponding to 15.29 ng·L−1 and good linearity was shown between the relative SERS intensity and nitrite concentration range of 10–1 to 10−4 mol/L. The Ag-coated nanofiber SERS platform was utilized to assay-five common nitrite foods, and the results provided valid evidence for the compatibility of SERS platform in quantitative nitrite detection. [ABSTRACT FROM AUTHOR]

[Display omitted] We report herein a new highly selective fluorescent probe QVPB-DNP for selective evaluation of H 2 S in the solid states and food samples. In this probe, a quinoline-phenol vinylic conjugated skeleton as well as the expanded benzothiazole moiety (QVPB-OH) is selected as the fluorophore and a 2,4‑dinitrophenyl (DNP) ether is chosen as binding site of H 2 S. The probe shows significant variations in UV/visible absorption (Stokes Shift = 160 nm) and fluorescence emission enhancement at 605 nm for selective detection of H 2 S in DMSO/PBS system (v/v , 7:3, PBS buffer; pH 7.4). Moreover, probe QVPB-DNP -loaded test strips are successfully applied for the visual and real-time detection of gaseous H 2 S in practical food samples. [ABSTRACT FROM AUTHOR]

[Display omitted] • L5 can achieve naked-eye recognition for I−. • The mechanism of subject-object recognition was elucidated. • The method can be used for I− detection in food. • L5 has lower detection limit and higher sensitivity. In this study, a cholesteric chiral artificial receptor L5 was synthesized and a rapid method for the detection of iodide ions was established. The addition of L5 to Ethanol/Tris (V/V = 1/1, pH 7.0) solution changed the iodide ion solution from colorless to light yellow to achieve the naked-eye identification. The identification pattern was confirmed with the help of spectral titration, job test and anti-interference test, and it was found that L5 bound to iodide ion in a 1:1 coordination ratio. It was also confirmed that the hydrogen atoms of the amide group of MeO-PhCONH in L5 and the hydrogen atoms of –COOCH 3 in L5 interacted with I− through hydrogen bonding force by 1H NMR titration, infrared spectroscopy, scanning electron microscopy and computer molecular simulation. The detection limit of L5 was 0.025 µmol/L, which could efficiently and conveniently detect iodide ions in food samples. [ABSTRACT FROM AUTHOR]

Formaldehyde (FA) is an environmental toxin and widely used in building and decorating materials, which is listed as a class 1 carcinogen. Silver ion (Ag+) has a beneficial bactericidal effect, while it can also cause silver poisoning and skin damage. Therefore, developing a quantitative detection technique for formaldehyde and Ag+ is necessary. In this study, a novel difunctional fluorescent probe (DBP) was designed and synthesized based on the natural product dehydroabietic acid, which could selectively detect formaldehyde and Ag+ through "turn-on" and "turn-off" fluorescence response, respectively. The probe DBP performed satisfactory nanomolar-level detection limit to formaldehyde (38 nM) and Ag+ (19 nM) in ethanol/PBS (3/7, v/v, pH = 7.4) solution. Furthermore, DBP could effectively recognize formaldehyde and Ag+ within a short response time (FA: 15 min, Ag+: 100 s) and a wide pH range (5–10). The sensing mechanisms of DBP to FA and Ag+ were well verified by 1H NMR titration, ESI-MS, DFT computation, and Job's plot analysis. What is more, the applications in bioimaging were carried out in MCF-7 cells and living zebrafish. Besides, the probe DBP was successfully applied in detecting FA and Ag+ in actual food and water samples, and the DBP -loaded filter paper was prepared for convenient tracking gaseous FA and Ag+. • A novel fluorescent probe DBP for detecting formaldehyde and Ag+ was synthesized. • DBP exhibits low LOD, short response time and wide pH range towards FA and Ag+. • DBP was utilized in food and water samples, filter paper test, and bioimaging. [ABSTRACT FROM AUTHOR]

The high quantum-yield (QY) lignin fluorescence material at solid state was obtained via the polymer confinement strategy, using polyvinyl alcohol (PVA) as polymer matrix and organic solvent lignin (OL) as luminescent material. The absolute QY of lignin/PVA film could reach 13.68 % by optimizing the raw material of OL, of which was even higher than that in THF medium due to their hydrogen bond interaction for inhibiting aggregation and rigid environment for decreasing molecular rotation and vibration. In addition, under the encapsulation of PVA, the resistance of photobleaching of lignin fluorescence was also enhanced. Finally, OL was proved as a natural ratiometric fluorescence pH sensor from the electronegativity change of phenylpropane unit, and the fluorescence of lignin/PVA film showed a naked-eye recognition for spoiled pork detection. This work provided a new perspective to lignin fluorescence for really using as a feedstock for luminescent materials. • High QY lignin fluorescent material at solid-state is obtained by polymer confinement. • Absolute QY of doping film could reach 13.68% by optimizing the raw material of OL. • A naked-eye recognition displays from the natural ratiometric pH response of lignin. [ABSTRACT FROM AUTHOR]

Acrolein is a highly toxic agent that can be generated exogenously and endogenously. Therefore, a highly specific and sensitive probe for acrolein with potential applications in acrolein detection must be developed. In this research, a novel fluorescent probe named "probe for acrolein detection" (Pr-ACR) was designed and synthesized based on a naphthalimide fluorophore skeleton, and a thiol group (-SH) was introduced into its structure for acrolein recognition. The -SH traps acrolein via Michael addition and the resultant interaction product of the probe inhibits the photoinduced electron transfer process and produce a strong fluorescence at 510 nm. The probe showed high sensitivity and specificity for acrolein. HPLC-MS/MS analysis verified that it can be used to quantify acrolein in foods, such as soda crackers, red wine, and baijiu, with a fluorescence spectrophotometer. After methyl esterification, the methyl esterified probe (mPr-ACR) successfully visualised acrolein in Hela cells under a laser scanning confocal microscope. This finding proved that Pr-ACR and mPr-ACR are potential tools for the detection and visualisation of acrolein from different sources. [Display omitted] • A napthalimide-based fluorescent probe was developed for sensitive detection of acrolein. • It recognized acrolein through thiol participation in Michael addition. • It was used to quantitatively determine acrolein in different foods. • It successfully tracked acrolein in Hela cells. [ABSTRACT FROM AUTHOR]

Cr3+-doped Ca 3 Y 2 Ge 3 O 12 broadband near-infrared phosphor was synthesized by the high temperature solidstate reaction method. Under the excitation of 475 nm, the emission peak of Ca 3 Y 2 Ge 3 O 12 :Cr3+ is at 823 nm and the full width at half maximum (FWHM) is 155 nm. The introduction of Ce3+ as a sensitizer leads to the enhancement of CYG:Cr3+ emission intensity. The emission range of CYG:Ce3+, Cr3+ can perfectly cover the frequency doubling absorption band of C–H, O–H and other hydrogen groups. There is an energy transfer process between Ce3+ and Cr3+, and the energy transfer efficiency is as high as 94.21%. According to the near-infrared response to hydrogen group and Lambert-Beer law, the dependence of absorbance Lg(I 0 / I) on sugar content was explored, and then the reliability and accuracy of the method were verified. The results show that the phosphor Ca 3 Y 2 Ge 3 O 12 :Ce3+, Cr3+ phosphor has prospects for a potential application in nondestructive food detection. • There is the energy transfer from Ce3+ to Cr3+. • CYG:Ce3+, Cr3+ has certain application value in nondestructive food detection. • The best excitation wavelength of the sample is 475 nm, which can be effectively excited by the blue light chip, and the FWHM is 155 nm. [ABSTRACT FROM AUTHOR]