Food Safety Research Articles

Chinese consumers’ dish value: a best–worst scaling approach

PurposeThis paper aims to identify Chinese consumers’ dish value systems and investigate whether and to what extent their dish values vary by type of consumers.Design/methodology/approachWe used a best–worst scaling (BWS) developed based on previous literature on food values and attributes of Chinese dishes to elicit Chinese consumers’ dish value structure. Then, we estimated each participant’s share of preferences for dish values and applied Ward’s linkage cluster analysis to identify the heterogeneity of their dish values.FindingsOur results indicate that food safety values, including the safety of agricultural products, additives and food processing, are valued most by Chinese consumers. They rate health-nutrition values as the second most important dish values. There is significant heterogeneity in Chinese consumers' dish values. Their dish values tend to drive their dish consumption patterns.Originality/valueThe dish is the mainstay of the Chinese meal. This study is among a few studies that examine Chinese consumers’ dish values that underlie consumer dish preferences and choices. The results provide essential information to promote a healthy and sustainable diet among Chinese consumers by understanding their values and motivations for making dish choices.

Traditional insights into ITK and its delineation for sustainable crop protection

The challenge of producing sufficient food to feed the growing population is aggravated by pests and diseases, with insect pests alone causing 15-20 percent losses in food production. Despite the availability of numerous synthetic and conventional pesticides, traditional practices, known as Indigenous Technical Knowledge (ITK), have been utilized by farmers for generations and have been adequate to date. These practices are deeply rooted in local culture and are environmentally safe. ITKs are a wealth of agricultural wisdom intertwined with religious and cultural beliefs that have significantly contributed to plant protection. It considers the interconnectedness of all living beings and the natural environment. In the context of the current scenario, it is essential to preserve and safeguard these traditional practices. Numerous government centres and policies are dedicated to this goal, recognizing the importance of documenting ITK for future use. Although ITKs were initially practiced without scientific validation, modern research has characterized and supported many of these methods. This review emphasizes the significance of Indigenous Technical Knowledge, the support systems in place and the necessity of detailed documentation and scientific characterization of ITK in use. By focusing on preserving and validating ITKs, we can reduce reliance on harmful chemical pesticides, promote sustainable agricultural practices and ensure food safety and security.

Kantin Sehat dalam Meningkatkan Kebiasaan Makan Sehat pada Siswa Sekolah Dasar

Nutrition can be one of the main problems in school-age children. Malnutrition can trigger drowsiness and lack of enthusiasm, so that the learning process at school is disrupted. The problem of undernutrition and poor nutrition is directly influenced by food consumption patterns and infectious diseases. This study aims to determine the role of healthy canteens in improving healthy eating habits in elementary school students. This research uses a qualitative approach through the literature study method. Data collection was carried out by collecting various relevant and up-to-date references, including research articles published on Google Scholar, books, and other documents related to the substance of the problem in this study. Data analysis is carried out qualitatively through the stages of data reduction, data presentation, and conclusion drawing. The results of the analysis show that the school canteen program which began to be held in 2009 by the Ministry of National Education is one of the interventions to maintain food safety, especially in schools in Indonesia. Nutritional intake is quite important for the growth and development of children. The healthy canteen program in schools is an effort to encourage healthy eating habits from an early age. Healthy canteens provide nutritious food and become a means of nutrition education for students. Healthy canteens provide nutritious food and become a means of nutrition education for students

CRISPR-Cas12: A Versatile Tool for Genome Editing and Beyond

CRISPR-Cas systems are emerging gene editing toolkits that have been used for the manipulation of DNA and RNA, among which CRISPR-Cas12 demonstrates superior properties in terms of target DNA engineering in vivo compared to CRISPR-Cas9 as well as nucleic acid detection compared to CRISPR-Cas13. A comprehensive understanding of the mechanisms and emerging applications of CRISPR-Cas12-based technologies is critical for maximizing their benefits across various fields, including basic science, medicine, and food safety. In this study, we review the molecular features of both natural and engineered CRISPR-Cas12 compared to CRISPR-Cas9 and CRISPR-Cas13, and we provide an overview of established CRISPR-Cas12-based genome editing and diagnostic platforms. Furthermore, we discuss the advantages, challenges, and prospects for future directions of CRISPR-Cas12 in gene editing and nucleic acid detection.

Antimicrobial Peptides, Their Production, and Potential in the Fight Against Antibiotic-Resistant Pathogens

The article reviews the literature on antimicrobial peptides (AMPs) that exhibit unique antimicrobial mechanisms, such as broad-spectrum activity, low development of antimicrobial resistance, and the ability to modulate the immune response of the host organism. Information is provided on the significant potential of AMPs in the fight against pathogens threatening human health and food safety. Enrichment of the human diet with biologically active peptides obtained using the proteolytic activity of lactic acid bacteria (LAB) is proposed as a simple, accessible, and viable alternative to antibiotics that does not have a harmful side effect. The review briefly covers the methods for obtaining AMPs and features of the LAB proteolytic system responsible for producing bioactive peptides in the environment. It has been shown that using various LAB strains makes it possible to produce high-quality whey-based beverages with different directions of antagonistic activity against opportunistic pathogens and helps optimize the gastrointestinal microbiota. It is assumed that such drinks can reduce the dose of antimicrobials in the combined therapy of various infectious diseases and be a preventive measure against contagion and the spread of antimicrobial resistance.

A practical fluorometric and colorimetric dual-mode sensing platform based on two-dimensional porous organic nanosheets for rapid determination of trifluralin.

Trifluralin, a widely used dinitroaniline herbicide, poses significant toxic risks, necessitating the development of rapid detection methods for food safety. In this study, we prepared ultrathin two-dimensional triphenylamine porous organic nanosheets (TPA-PONs) through a facile liquid-phase exfoliation process. The TPA-PONs, characterized by their exceptional fluorescence properties and nanoscale thickness (1.65 ± 0.3 nm), demonstrated a remarkable fluorescence quenching response upon exposure to trifluralin. Spectroscopic analysis combined with DFT calculations revealed that the quenching mechanism is driven by electron and energy transfer. TPA-PONs-based fluorescence sensor exhibited a linear response to trifluralin concentrations ranging from 0.01 to 10.0 μmol L-1 with a limit of detection as low as 3.50 nmol L-1. Additionally, the sensor was applied to detect trifluralin residues in vegetables, achieving recoveries of 89.08-102.84%. To facilitate on-site detection, a novel TPA-PONs-based colorimetric film sensor has been developed, enabling visual analysis of trifluralin using a smartphone. This dual-mode sensing platform holds significant potential for enhancing food safety monitoring.

Optimization of exogenous CeO2 nanoparticles on Pak choi (Brassica rapa L. var. chinensis) to alleviate arsenic stress

Arsenic (As) is a regulated hazardous substance that persists in the environment, causing issues related to environmental health, agriculture, and food safety. Cerium oxide nanoparticles (CeO2 NPs) are emerging sustainable solutions for alleviating heavy metal stress. However, their effectiveness and optimization for foliar application in reducing As stress, especially in Pak choi, has not been reported yet. Hence, this study aims to examine the effects of foliar application of CeO2 NPs (75,000,000, 150,000,000, and 300,000,000 ng/L) on the growth, nutrient availability, and antioxidant enzymatic activities of Pak choi plants under As stress. The findings showed that foliar application of 75,000,000 ng/L CeO2 NPs significantly increased shoot length (77.32%), root length (80.98%), and number of leaves (80.23%) as compared to control without NPs. The lowest dose of CeO2 NPs (75,000,000 ng/L) increased antioxidant enzyme activities such as peroxidase (86.10%), superoxide dismutase (81.48%), and catalase (52.07%), while significantly reducing malondialdehyde (44.02%), hydrogen peroxide (34.20%), and electrolyte leakage (43.53%). Furthermore, foliar application of 75,000,000 ng/L CeO2 NPs significantly increased the content of zinc (81.02%), copper (56.99%), iron (88.04%), manganese (68.37%), magnesium (76.83%), calcium (61.16%), and potassium (84.91%) in leaves when compared to control without NPs. The same trend was observed for shoot and root nutrient concentrations. Most importantly, 75,000,000 ng/L CeO2 NPs foliar application significantly reduced shoot As (45.11%) and root As (20.89%) concentration compared to control, providing a reassuring indication of their potential to reduce As concentration in plants. Our study’s findings are of utmost importance as they indicate that lower concentrations of foliar-applied CeO2 NPs can be more effective in enhancing crop nutrition and reducing heavy metals than higher concentrations. This article is intended to present critical issues of As contamination in agricultural soils, which imposes substantial risks to crop productivity and food security.

Leveraging social media data in knowledge management to identify noncompliance: insights from the foodservice industry

Purpose Social media data contains a wealth of content related to customers’ reactions to, and comments on, firms’ performance. Through the lens of signaling theory, this paper aims to investigate the use of social media data as a knowledge resource in communicating firms’ noncompliance risk to regulatory agencies. Design/methodology/approach This paper proposes a two-step social media analytics framework to detect noncompliant firms. First, it creates a context-specific dictionary that contains keywords relevant to firms’ noncompliant behaviors. Next, it extracts those keywords from customer reviews, customer sentiment and emotions to predict firm noncompliance. It tests these ideas in the context of food safety regulations. Findings It identified over 100 words that are related to restaurants’ hygiene deficiencies. Using the occurrence of these words in customer reviews, as well as sentiments and emotions expressed within them, the author’s best-performing model can identify nearly 90% of the restaurants that severely violated regulations. Practical implications After being processed by appropriate machine learning algorithms, customer reviews serve as valuable knowledge resources, enabling regulatory agencies to identify noncompliant firms. Regulatory agencies can use this model to complement the current compliance monitoring scheme. Originality/value This research contributes a novel methodology for creating a context-specific dictionary that keeps only the relevant words customers use when discussing firms’ noncompliant acts. In the absence of such an approach, numerous irrelevant signals would be included in the modeling process, thereby increasing the cost of social media analytics.

Impact of Ex Vivo Bisphenol A Exposure on Gut Microbiota Dysbiosis and Its Association with Childhood Obesity

Dietary exposure to the plasticiser bisphenol A (BPA), an obesogenic and endocrine disruptor from plastic and epoxy resin industries, remains prevalent despite regulatory restriction and food safety efforts. BPA can be accumulated in humans and animals, potentially exerting differential health effects based on individual metabolic capacity. This pilot study examines the impact of direct ex vivo BPA exposure on the gut microbiota of obese and normal-weight children, using 16S rRNA amplicon sequencing and anaerobic culturing combined methods. Results showed that direct xenobiotic exposure induced modifications in microbial taxa relative abundance, community structure, and diversity. Specifically, BPA reduced the abundance of bacteria belonging to the phylum Bacteroidota, while taxa from the phylum Actinomycetota were promoted. Consistently, Bacteroides species were classified as sensitive to BPA, whereas bacteria belonging to the class Clostridia were identified as resistant to BPA in our culturomics analysis. Some of the altered bacterial abundance patterns were common for both the BPA-exposed groups and the obese non-exposed group in our pilot study. These findings were also corroborated in a larger cohort of children. Future research will be essential to evaluate these microbial taxa as potential biomarkers for biomonitoring the effect of BPA and its role as an obesogenic substance in children.

Lab-on-paper for molecular testing with USB-powered isothermal amplification and fluidic control.

The global healthcare market increasingly demands affordable molecular diagnostics for field testing. To address this need, we introduce a lab-on-paper (LOP) platform that integrates isothermal amplification with a specially designed paper strip for molecular testing through an automated microfluidics process. The LOP system is engineered for rapid, cost-effective, and highly sensitive detection, using USB-powered thermal management and a wax valve mechanism. This innovative platform provides an accessible solution for the rapid and accurate detection of various microorganisms, proving particularly advantageous for point-of-care testing in resource-limited environments. Experiments conducted in this study demonstrated the efficacy of the LOP platform in the colorimetric detection of foodborne pathogens. It reliably detected Vibrio vulnificus at concentrations as low as 120CFU/mL and Salmonella Typhimurium at 60CFU/mL, with results observable to the naked eye. The entire process, encompassing amplification and detection, was completed within 30min, underscoring the system's rapid diagnostic capability. Furthermore, with an assay cost of 5.2 USD per test, the platform offers a highly cost-effective solution for molecular diagnostics, particularly in resource-limited settings. The LOP platform's portability, ease of use, and affordability make it a promising alternative for various diagnostic applications, including infectious disease monitoring and ensuring food safety.

Evaluation of ozonated and ultrasonically treated corn starch as an adsorbent for patulin in buffer solutions

This study evaluates the potential of ozonated corn starch (OCS) and ultrasonicated ozonated corn starch (USOCS) as adsorbents for patulin removal in buffer solutions. The results indicated that dual modification significantly altered the starch’s structure, introducing functional groups such as carbonyl and carboxyl groups, and increasing its surface area. These modifications led to enhanced patulin adsorption capacity. Adsorption efficiency was tested across different adsorbent doses (150 mg, 200 mg, 250 mg) and contact times (15, 30, 45, and 60 min). The highest removal efficiency of 92.5% was recorded for the 250 mg dose at 60 min, with USOCS showing superior performance compared to native corn starch and OCS. Kinetic studies revealed that the pseudo-second-order model provided the best fit for the adsorption process, indicating chemisorption as the dominant mechanism. The Langmuir and Freundlich isotherms were used to describe the adsorption behavior, with a maximum adsorption capacity (qmax) of 15.19 µg/mg and a Langmuir constant (KL) of 54.00 L/µg for the 250 mg dose. Additionally, the modified starch demonstrated consistent adsorption performance at varying concentrations, with a favorable adsorption intensity (n > 1), supporting its potential for practical applications. These findings highlight the modified corn starch as an efficient, biodegradable, and low-cost adsorbent suitable for mitigating patulin contamination in food products, offering a sustainable alternative for improving food safety.

Effects of dietary oregano essential oil supplementation on carcass traits, muscle fiber structure, oxidative stability, meat quality, and regulatory mechanisms in Holstein steers.

Dietary supplementation for beef cattle, using natural plant extracts, such as oregano essential oil (OEO), has proven effective in enhancing growth performance, beef production quantity and quality, and ensuring food safety. However, the precise mechanisms underlying these effects remain unclear. This study investigated the impact of OEO on carcass traits, muscle fiber structure, meat quality, oxidative status, flavor compounds, and gene regulatory mechanisms in the longissimus thoracis (LT) muscles of beef cattle. Eighteen steers were randomly assigned to two groups (n = 9 per group) and fed either a control diet (CK) or the same diet supplemented with 20 g of OEO per head per day for 300 days. Oregano essential oil supplementation improved the body weight, carcass weight, meat production, area and diameter of fiber, ether extract, and water-holding power of muscle. Increasing catalase (CAT), peroxidases (POD), glutathione peroxidase (GSH-Px) and by decreasing lipid droplets (LDs) reduced muscle lipid oxidation. However, the color (L*, a*, b*, C* and H°) and the flavor compounds of muscle were affected adversely by OEO. The transcriptome and metabolome indicated the OEO group enriched fat synthesis, proteo-metabolism, antioxidants, and growth significantly. Five key genes (SH2B2, CD209, LOC504773, C1QC, and HMOX) and ten downregulated metabolites (deoxyguanosine, d-melezitose, maltotriose, raffinose, melatonin, quinic acid, orotic acid, hydrocinnamic acid, 2-methylsuccinic acid, and pyridoxal 5'-phosphate) were identified as key biomarkers. These interacted to positively influence the growth, oxidative status, and meat quality of steers positively. These findings suggest that OEO, as a natural bioactive compound, can serve as an additive for beef cattle, with a daily dose of 20 g per steer improving growth and meat quality, although it may affect muscle color and flavor negatively. © 2025 Society of Chemical Industry.

Electrochemical Method for the Assay of Organic Peroxides Directly in Acetonitrile

Lipid peroxidation is a major process that determines the quality of various oil samples during their use and storage, in which the primary products are hydroperoxides (HP’S). HP’S are very stable compounds at ambient conditions and are harmful to human health. Therefore, the evaluation of the degree of oil oxidation is an excellent tool for ensuring food safety. The peroxide value (PV) is the main parameter used for quality control in oils. Herein, we propose an alternative electrochemical method to the classical iodometric titration method most widely used for determining the PV. Our approach is based on the electrochemical quantification of hydroperoxides/peroxides in an organic solvent medium (acetonitrile and organic ammonium salt) using a composite electrocatalyst–glassy carbon electrode modified with 2D-nanomaterial graphitic carbon nitride doped with Co3O4. Calibration was made by the method of standard addition using benzoyl peroxide (BPO) as a model peroxide compound, dissolved in chloroform and added to fresh Rivana-branded anti-cellulite oil, used as a model oil sample. Calibration plots showed a linear response and the very good reproducibility of the analytical result (R2 ˃ 0.99). Further, in terms of accuracy, the method showed good results, since the BPO quantitative analysis was close to the theoretical response. In addition, the accuracy of the electrochemical method was compared with that of the standard iodometric titration method for determining the PV of vegetable fats (according to a standard method). Finally, using the electrochemical method, the concentration of peroxides was determined in a real sample—an anti-cellulite oil of the trademark Rivana with an expired shelf life.

Bacteriocin-Producing Staphylococci and Mammaliicocci Strains for Agro-Food and Public Health Applications with Relevance of Micrococcin P1

Antimicrobial-producing strains and their bacteriocins hold great promise for the control of bacterial diseases, being an attractive alternative to antibiotics. Thus, the aim of this study was to evaluate the inhibitory activity of 15 bacteriocin-producing staphylococci and mammaliicocci (BP-S/M) strains and their pre-purified extracts with butanol (BT) against a collection of 27 harmful or zoonotic strains (including Gram-positive/-negative bacteria and molds) with relevance in the public health and agro-food fields. These indicators (excluding Gram-negative strains) were grouped into seven categories based on their potential application areas: dairy livestock mastitis, avian pathogen zoonoses, swine zoonoses, food safety, aquaculture, wine making, and mushroom cultivation. In addition, cross-immunity assays between the BP-S/M strains were carried out to identify potential strain combinations to enhance their activity against pathogens. Finally, the hemolytic and gelatinase activities were tested in the BP-S/M strains. A strong inhibitory capacity of the BP-S/M strains was verified against relevant Gram-positive indicators, such as methicillin-resistant Staphylococcus aureus, Listeria monocytogenes, and Clostridium perfringens, among others, while no activity was detected against Gram-negative ones. Interestingly, several BT extracts inhibited the two mold indicators included in this study as representants of mushroom pathogens. The Micrococcin P1 producer Staphylococcus hominis C5835 (>60% of indicators were intensively inhibited by all the methods) can be proposed as a potential candidate for the control of bacterial diseases in the aforementioned categories alone or in combination with other BP-S/M strains (mainly with Staphylococcus warneri X2969). In this regard, five potential combinations of BP-S/M strains that enhanced their activity against specific pathogens were detected.

Optimization of the Extraction Protocol for Pacific Ciguatoxins from Marine Products Prior to Analysis Using the Neuroblastoma Cell-Based Assay

Ciguatera poisoning (CP) is caused by the consumption of marine products contaminated with ciguatoxins (CTXs) produced by dinoflagellates of the genus Gambierdiscus. Analytical methods for CTXs, involving the extraction/purification of trace quantities of CTXs from complex matrices, are numerous in the literature. However, little information on their effectiveness for nonpolar CTXs is available, yet these congeners, contributing to the risk of CP, are required for the establishment of effective food safety monitoring programs. An evaluation of six extraction/purification protocols, performed with CTX3C spiked on fish flesh and a neuroblastoma cell-based assay (CBA-N2a), revealed recoveries from 6 to 45%. This led to the development of an optimized 3-day protocol designed for a large number of samples, with CTX1B and CTX3C eluting in a single fraction and showing recoveries of 73% and 70%, respectively. In addition, a reduction in adverse matrix effects in the CBA-N2a analyses was demonstrated with naturally contaminated specimens, increasing the sensitivity of the method, which now meets the very low guidance level recommended by international agencies. However, efforts are still required to reduce the signal suppression observed in LC-MS/MS analysis. This optimized protocol contributes to the technological advancement of detection methods, promoting food safety and improving CP risk assessment in marine products.

High-level biosynthesis and purification of the antimicrobial peptide Kiadin based on non-chromatographic purification and acid cleavage methods

Antimicrobial peptides (AMPs) are renowned for their potent bacteriostatic activity and safety, rendering them invaluable in animal husbandry, food safety, and medicine. Despite their potential, the physiological toxicity of AMPs to host cells significantly hampers their biosynthetic production. This study presents a novel approach for the biosynthesis of the antimicrobial peptide Kiadin by engineering a DAMP4–DPS–Kiadin fusion protein to mitigate host cell toxicity and achieve high-level expression. Leveraging the unique properties of the DAMP4 protein, we developed a non-chromatographic purification method to isolate the DAMP4–DPS–Kiadin fusion protein with high purity. The instability of the D–P peptide bond under acidic conditions, combined with the thermal and saline stability of DAMP4, enabled efficient separation of Kiadin through acid cleavage and isoelectric precipitation, yielding Kiadin with 96% purity and a production yield of 29.3 mg/L. Our optimization of acid cleavage temperature, duration, and isoelectric precipitation conditions proved critical for maximizing the purification efficiency and expression levels of Kiadin. The biosynthesized Kiadin exhibited robust bacteriostatic activity against Escherichia coli, Pseudomonas aeruginosa, Acinetobacter baumannii, Bacillus cereus and Staphylococcus aureus. Notably, Kiadin demonstrated significant post-antibiotic effects by disrupting bacterial membrane integrity, inducing cytoplasmic leakage, and inhibiting biofilm formation in E. coli K88 and S. aureus Mu50, without cytotoxicity towards mouse macrophages. In vivo studies further confirmed Kiadin's exceptional therapeutic efficacy against abdominal infections caused by E. coli K88. The acid cleavage and non-chromatographic purification techniques developed in this study offer a cost-effective and efficient strategy for the high-purity production of AMPs.

From Traditional Typing to Genomic Precision: Whole-Genome Sequencing of Listeria monocytogenes Isolated from Refrigerated Foods in Chile

Ready-to-eat (RTE) foods are the most common sources of Listeria monocytogenes transmission. Whole-genome sequencing (WGS) enhances the investigation of foodborne outbreaks by enabling the tracking of pathogen sources and the prediction of genetic traits related to virulence, stress, and antimicrobial resistance, which benefit food safety management. The aim of this study was to evaluate the efficacy of WGS in the typing of 16 L. monocytogenes strains isolated from refrigerated foods in Chile, highlighting its advantages in pathogen identification and the improvement of epidemiological surveillance and food safety. Using cgMLST, a cluster was identified comprising 2 strains with zero allele differences among the 16 strains evaluated. Ninety-four percent of the isolates (15/16) were serotype 1/2b, and 88% of them (14/16) were ST5. All strains shared identical virulence genes related to adhesion (ami, iap, lapB), stress resistance (clpCEP), invasion (aut, iapcwhA, inlAB, lpeA), toxin production (hly), and intracellular regulation (prfA), with only 13 strains exhibiting the bcrBC and qacJ gene, which confer resistance to quaternary ammonium. The pCFSAN010068_01 plasmids were prevalent, and insertion sequences (ISLs) and composite transposons (cns) were detected in 87.5% of the strains. The presence of various antibiotic resistance genes, along with resistance to thermal shocks and disinfectants, may provide L. monocytogenes ST5 strains with enhanced environmental resistance to the hygiene treatments used in the studied food production plant.

Extremophiles and their Potentials in the Food Industries: A Review

Extremophiles are microorganisms that thrive in extreme environments, such as high temperatures, high pressures, and acidic or alkaline conditions. These organisms have unique adaptations that allow them to survive in these harsh conditions, and they are of great interest to the food industry for a variety of applications. Extremophilic microorganisms produce a broad range of bioactive compounds, secondary metabolites, and value-added products such as flavors, food ingredients, and vitamins, therefore, making them widely applicable in the food and food processing industries. In food industries, one of the extremophiles, Rhodothermus marinus, which has been an excellent biocatalyst producing lipase as an enzyme, could be utilized to improve the aroma of food and add natural flavor to food. Others have emerged as a valuable resource for the food industry, offering solutions to food safety and preservation challenges, as well as opportunities for sustainable food processing. By harnessing the unique characteristics and enzymes of extremophiles, the food industry can improve product quality, develop novel fermentation processes, and enhance food safety. Extremophiles hold significant potential for use in the food industry; however, translating this potential into practical applications is fraught with several challenges. These challenges include specialized growth conditions, slow growth rate, and contamination risks. Advancing genetic, biotechnological, and engineering research will be pivotal in realizing the full potential of extremophiles. Ongoing exploration of these organisms is crucial not only for improving food production processes but also for fostering sustainability and driving innovation within the food industry.

Single-Atom Iridium-doped Carbon Dots Nanozyme with High Peroxidase-Like Activity as Colorimetric Sensors for Multimodal Detection of Mercury Ions.

Nanozyme-based colorimetric sensors are promising approaches for environmental monitoring, food safety, and medical diagnostics. However, developing novel nanozymes that exhibit high catalytic activity, good dispersion in aqueous solution, high sensitivity, selectivity, and stability is challenging. In this study, for the first time, single-atom iridium-doped carbon dot nanozymes (SA Ir-CDs) are synthesized via a simple in situ pyrolysis process. Doping carbon dots with iridium in the form of single atoms to achieve maximum atomic utilization not only enhances peroxidase (POD)-like activity to 178.81 U mg-1 but also improves the dispersibility of single-atom nanozymes in aqueous solutions over 30 days. Hence, the SA Ir-CD colorimetric platform is developed for mercury ions (Hg2+) detection and exhibited a good linear relationship from 0.01 to 10 µm and a detection limit of 4.4 nm. Notably, the changes in color can be observed not only through the naked eye but also via a smartphone, enabling convenient field and onsite monitoring without the need for sophisticated analytical equipment. In this study, an approach for fabricating single-atom metal-based carbon dot nanozymes with high POD-like activity is developed, and a new effective and easy-to-use colorimetric sensor for Hg2+ detection is constructed.

Applications of Nanomaterial Coatings in Solid-Phase Microextraction (SPME)

This review explores the advances in developing adsorbent materials for solid-phase microextraction (SPME), focusing on nanoparticles, nanocomposites, and nanoporous structures. Nanoparticles, including those of metals (e.g., gold, silver), metal oxides (e.g., TiO2, ZnO), and carbon-based materials (e.g., carbon nanotubes, graphene), offer enhanced surface area, improved extraction efficiency, and increased selectivity compared to traditional coatings. Nanocomposites, such as those combining metal oxides with polymers or carbon-based materials, exhibit synergistic properties, further improving extraction performance. Nanoporous materials, including metal–organic frameworks (MOFs) and ordered mesoporous carbons, provide high surface area and tunable pore structures, enabling selective adsorption of analytes. These advanced materials have been successfully applied to various analytes, including volatile organic compounds (VOCs), polycyclic aromatic hydrocarbons (PAHs), pesticides, and heavy metals, demonstrating improved sensitivity, selectivity, and reproducibility compared to conventional SPME fibers. The incorporation of nanomaterials has significantly expanded the scope and applicability of SPME, enabling the analysis of trace-level analytes in complex matrices. This review highlights the significant potential of nanomaterials in revolutionizing SPME technology, offering new possibilities for sensitive and selective analysis in environmental monitoring, food safety, and other critical applications.