Biosensors in food processing

A contemporary overview on quantum dots-based fluorescent biosensors: Exploring synthesis techniques, sensing mechanism and applications

In the epoch of bioinformatics, pivotal biomedical scrutiny and clinical diagnosis hinge upon the unfolding of highly efficacious biosensors for intricate and targeted identification of specific biomolecules. In pursuit of developing robust biosensors endowed with superior sensitivity, precise selectivity, rapid performance, and operational simplicity, semiconductor QDs have been acknowledged as pivotal and advantageous entities. In this review, we present a comprehensive analysis of the latest unfolding within the domain of QDs used in fluorescent biosensors for the detection of diverse biomolecular entities, encompassing proteins, nucleic acids, and a range of small molecules, with an emphasis on the synthesis methodologies of QDs employed and mechanism behind sensing. Additionally, this review delves into several pivotal facets of QD-based fluorescent biosensors in detail, such as surface functionalization methodologies aimed at enhancing biocompatibility and improving target specificity. The challenges and future perspectives of QD-based fluorescent biosensors are also considered, emphasizing the necessity of ongoing multidisciplinary research to realize their full potential in enhancing personalized medicine and biomedical diagnostics.

Bacillus subtilis surface display technology: applications in bioprocessing and sustainable manufacturing

The growing demand for sustainable and eco-friendly alternatives in bioprocessing, healthcare, and manufacturing has stimulated significant interest in Bacillus subtilis surface display technology. This innovative platform, leveraging both spore and vegetative cell forms, provides exceptional versatility for a wide spectrum of applications, spanning from green technologies to advanced biomedical innovations. The robustness of spores and the metabolic activity of vegetative cells enable efficient enzyme immobilization, biocatalysis, and biosensor development, facilitating bioremediation, pollutant degradation, and renewable energy generation. Additionally, B. subtilis surface display systems have demonstrated remarkable potential in vaccine development and drug delivery, offering a cost-effective, scalable, and environmentally sustainable alternative to traditional methods. These systems can effectively present antigens or therapeutic molecules, enabling targeted drug delivery and robust immune responses. This review explores recent advancements, challenges, and opportunities in harnessing B. subtilis surface display technology for sustainable biomanufacturing, green innovations, and transformative biomedical applications, emphasizing its role in addressing pressing global challenges in environmental sustainability and healthcare.

Construction of flexible paper-based sensor for label-free recognition of histamine in cow meat samples by conductive nano-silver ink: a new platform for the analysis of biogenic amines towards early diagnosis of meat spoil

Biogenic amines are organic nitrogen compounds that play key roles in various biological processes and are produced through amino acid decarboxylation. Among these, histamine stands out as a toxic biogenic amine with the potential to cause serious health issues when present at elevated levels in food, highlighting the importance of effective detection methods. However, current histamine detection approaches are often hindered by high costs, lengthy analysis times, and intricate procedures. This research introduces a novel, label-free method for detecting histamine in meat samples using highly conductive nano-silver inks to develop miniaturized sensors based on paper microdevice technology. The proposed paper-based electrochemical sensors offer significant advantages, including affordability, reproducibility, and environmental sustainability. A newly designed paper-based microsensor was developed for label-free histamine detection employing conductive nano-silver ink via a pen-on-paper technique. The fabrication process of the microsensor was thoroughly characterized through methods like field emission scanning electron microscope (FE-SEM), Energy Dispersive X-ray (EDAX), and Atomic Force microscopy (AFM). Key findings indicate that the microsensor successfully detects histamine concentrations across a broad dynamic range of 10 to 1000 nM, with a lower limit of quantification set at 10 nM. Validation of the sensor's performance was conducted using electrochemical tools such as cyclic voltammetry and square wave voltammetry, confirming its efficacy for real-time histamine monitoring in food products and biological environments. Additionally, the study underscores the sensor's excellent selectivity, long-term stability, and lightning-fast responsiveness, positioning it as a highly promising tool to enhance food safety and quality assurance.

Basic strategies for monitoring lipase activity: A review

Lipases are involved in the basic metabolism of many organisms from simple microorganisms to mammals. Moreover, these versatile biocatalysts can catalyze various types of reactions, such as esterification, interesterification, aminolysis, hydrolysis, and many important classic organic reactions under mild conditions, which play critical roles in industrial catalysis, drug discovery, and medical diagnosis of diseases. The heterogeneous nature of this catalysis requires intimate contact between them and lipid emulsion droplets. The lipolytic activity of production isolates could be determined by monitoring the release of fatty acids. Therefore, adequate monitoring of the reaction medium is critical to gain mechanistic knowledge of lipid hydrolysis in response to changes in process conditions. This review paper provides an overview of the principles underlying different strategies for monitoring lipid hydrolysis. The strengths and limitations of each method are analyzed to provide practical guidance for future research.

Long-Term and Continuous Plasmonic Oligonucleotide Monitoring Enabled by Regeneration Approach

The demand for continuous monitoring of biochemical markers for diagnostic purposes is increasing as it overcomes the limitations of traditional intermittent measurements. This study introduces a method for long-term, continuous plasmonic biosensing of oligonucleotides with high temporal resolution. Our method is based on a regeneration-based reversibility approach that ensures rapid reversibility in less than 1 minute, allowing the sensor to fully reset after each measurement. We investigated label-free and AuNP enhancements for different dynamic ranges and sensitivities, achieving a limit of detection down to pM levels. We developed a regeneration-based reversibility approach for continuous biosensing, optimizing buffer conditions using the Taguchi method to achieve rapid, consistent reversibility, ensuring reliable performance for long-term monitoring. We detected oligonucleotides in buffered and complex solutions, including undiluted and unfiltered human serum, for up to 100 sampling cycles in a day. Moreover, we showed the long-term stability of the sensor for monitoring capabilities in buffered solutions and human serum, with minimal signal value drift and excellent sensor reversibility for up to 9 days. Our method opens the door to new prospects in continuous biosensing by providing insights beyond intermittent measurements for numerous analytical and diagnostic applications.

Biosensors for the detection of flaviviruses: A review

Flaviviruses affect the lives of millions of people in endemic regions and also have the potential to impact non-endemic areas. Factors such as climate change, global warming, deforestation, and increased travel and trade are linked to the spread of flaviviruses into new habitats and host species. Given the absence of specific treatments and the limited availability of vaccines, it is imperative to understand the biology of flaviviruses and develop rapid and sensitive diagnostic tests. These measures are essential for preventing the transmission of these potentially life-threatening pathogens. Flavivirus infections are mainly diagnosed using conventional methods. However, these techniques present several drawbacks, including high expenses, time-consuming procedures, and the need for skilled professionals. The search for fast, easy-to-use, and affordable alternative techniques as a feasible solution for developing countries is leading to the search for new methods in the diagnosis of flaviviruses, such as biosensors. This review provides a comprehensive overview of different biosensor detection strategies for flaviviruses and describes recent advances in diagnostic technologies. Finally, we explore their future prospects and potential applications in pathogen detection. This review serves as a valuable resource to understand advances in ongoing research into new biosensor-based diagnostic methods for flaviviruses.

Shape-Specific Gold Nanoparticles for Multiplex Biosensing Applications

The biosensing field faces a significant challenge in efficiently detecting multiple analytes in a single diagnostic sample in order to compete with other established multiplex molecular diagnostic technologies such as PCR and ELISA. In response, we have developed a colorimetric nanobiosensor based on multiple morphological forms of functionalized gold nanoparticles (AuNPs) for the simultaneous detection of the influenza virus and SARS-CoV-2 virus. Gold nanospheres (GNSp) were modified with oligonucleotides specific for the influenza A virus, while gold nanoshells (GNSh) were modified with oligonucleotides specific for the SARS-CoV-2 virus. In the presence of their respective targets, AuNPs remain stable due to DNA-DNA interactions; conversely, in the absence of targets, AuNPs aggregate. Consequently, the hybrid system exhibits an indigo color with the SARS-CoV-2 target, a blue color with the Influenza A target, and a purple color with both targets, visible to the naked eye. Analytical sensitivity was 100 nM, and no cross-reactivity was observed with potentially confounding pathogens. This approach holds great promise for the simultaneous identification of multiple pathogens in a rapid manner without the need for equipment or trained personnel.

Revolutionizing food safety with electrochemical biosensors for rapid and portable pathogen detection

Foodborne diseases remain a worldwide concern, despite the advances made in sanitation, pathogen surveillance and food safety management systems. The methods routinely applied for detecting pathogens in foods are time consuming, labor intensive and usually require trained and qualified individuals. The objective of this review was to highlight the use of biosensors, with a focus on the electrochemical devices, as promising alternatives for detecting foodborne pathogens. These biosensors present high speed for obtaining results, with the possibility of evaluating foods in real time, at low cost, ease of use, in addition to being compact and portable. These aspects are considered advantageous and suitable for use in food safety management systems. This work also shows some limitations for the application of biosensors, and we present perspectives with the development and use of nanomaterials.

Bioelectrochemical biosensors for water quality assessment and wastewater monitoring

Bioelectrochemical biosensors offer a promising approach for real-time monitoring of industrial bioprocesses. Many bioelectrochemical biosensors do not require additional labelling reagents for target molecules. This simplifies the monitoring process, reduces costs, and minimizes potential contamination risks. Advancements in materials science and microfabrication technologies are paving the way for smaller, more portable bioelectrochemical biosensors. This opens doors for integration into existing bioprocessing equipment and facilitates on-site, real-time monitoring capabilities. Biosensors can be designed to detect specific heavy metals such as lead, mercury, or chromium in wastewater. Early detection allows for the implementation of appropriate removal techniques before they reach the environment. Despite these challenges, bioelectrochemical biosensors offer a significant leap forward in wastewater monitoring. As research continues to improve their robustness, selectivity, and cost-effectiveness, they have the potential to become a cornerstone of efficient and sustainable wastewater treatment practices.

Seafood product safety: A hybrid graphene/gold-based electrochemical immunosensor for fish allergen analysis

Seafood product labels with accurate allergen contents can avoid and/or minimize allergic reactions. Therefore, an electrochemical immunosensor for the analysis of β-parvalbumin (β-PV, a major fish allergen) was developed. Screen-printed carbon electrodes were nanostructured with reduced graphene oxide and gold nanoparticles. The platform was characterized by scanning electron microscopy and elemental analysis. In a sandwich-type assay (∼75 min), the antigen-antibody interaction was detected by chronoamperometry using horseradish peroxidase and TMB-H2O2. A linear range of 25-3000 ng/mL, a sensitivity of 2.99 µA.mL/ng, and a limit of detection of 9.9 ng/mL (corresponding to 0.40 ng in the analysed aliquot) were obtained. The selectivity and possible interferences were assessed by analysing several other food allergens and a marine toxin. The sensor was applied to the analysis of 17 commercial foods and the effect of culinary processing (e.g., grilled, canned, smoked) on the β-PV concentration was assessed. Traces of β-PV were successfully quantified and ELISA was used to assess the results.

The Application of Multi-Parameter Multi-Modal Technology Integrating Biological Sensors and Artificial Intelligence in the Rapid Detection of Food Contaminants

Against the backdrop of continuous socio-economic development, there is a growing concern among people about food quality and safety. Individuals are increasingly realizing the critical importance of healthy eating for bodily health; hence the continuous rise in demand for detecting food pollution. Simultaneously, the rapid expansion of global food trade has made people's pursuit of high-quality food more urgent. However, traditional methods of food analysis have certain limitations, mainly manifested in the high degree of reliance on personal subjective judgment for assessing food quality. In this context, the emergence of artificial intelligence and biosensors has provided new possibilities for the evaluation of food quality. This paper proposes a comprehensive approach that involves aggregating data relevant to food quality indices and developing corresponding evaluation models to highlight the effectiveness and comprehensiveness of artificial intelligence and biosensors in food quality evaluation. The potential prospects and challenges of this method in the field of food safety are comprehensively discussed, aiming to provide valuable references for future research and practice.

Recent advances in nanomaterial-based optical biosensors for food safety applications: Ochratoxin-A detection, as case study

Global population growth tremendously impacts the global food industry, endangering food safety and quality. Mycotoxins, particularly Ochratoxin-A (OTA), emerge as a food chain production threat, since it is produced by fungus that contaminates different food species and products. Beyond this, OTA exhibits a possible human toxicological risk that can lead to carcinogenic and neurological diseases. A selective, sensitive, and reliable OTA biodetection approach is essential to ensure food safety. Current detection approaches rely on accurate and time-consuming laboratory techniques performed at the end of the food production process, or lateral-flow technologies that are rapid and on-site, but do not provide quantitative and precise OTA concentration measurements. Nanoengineered optical biosensors arise as an avant-garde solution, providing high sensing performance, and a fast and accurate OTA biodetection screening, which is attractive for the industrial market. This review core presents and discusses the recent advancements in optical OTA biosensing, considering engineered nanomaterials, optical transduction principle and biorecognition methodologies. Finally, the major challenges and future trends are discussed, and current patented OTA optical biosensors are emphasized for a particular promising detection method.

Label-free and label-based electrochemical detection of disease biomarker proteins

Introduction

Biosensors, analytical devices integrating biological sensing elements with physicochemical transducers, have gained prominence as rapid and convenient tools for monitoring human health status using biochemical analytes. Due to its cost-effectiveness, simplicity, portability, and user-friendliness, electrochemical detection has emerged as a widely adopted method in biosensor applications. Crucially, biosensors enable early disease diagnosis by detecting protein biomarkers associated with various conditions. These biomarkers offer an objective indication of medical conditions that can be accurately observed from outside the patient.

Method

This review comprehensively documents both label-free and labelled detection methods in electrochemical biosensor techniques. Label-free detection mechanisms elicit response signals upon analyte molecule binding to the sensor surface, while labelled detection employs molecular labels such as enzymes, nanoparticles, and fluorescent tags.

Conclusion

The selection between label-free and labelled detection methods depends on various factors, including the biomolecular compound used, analyte type and biological binding site, biosensor design, sample volume, operational costs, analysis time, and desired detection limit. Focusing on the past six years, this review highlights the application of label-free and labelled electrochemical biosensors for detecting protein biomarkers of diseases.

The Magnitude and Impact of Food Allergens and the Potential of AI-Based Non-Destructive Testing Methods in Their Detection and Quantification

Reaction to food allergens is on the increase and so is the attending cost on consumers, the food industry, and society at large. According to FDA, the "big-eight" allergens found in foods include wheat (gluten), peanuts, egg, shellfish, milk, tree nuts, fish, and soybeans. Sesame was added to the list in 2023, making the target allergen list nine instead of eight. These allergenic foods are major ingredients in many food products that can cause severe reactions in those allergic to them if found at a dose that can elicit a reaction. Defining the level of contamination that can elicit sensitivity is a work in progress. The first step in preventing an allergic reaction is reliable detection, then an effective quantification method. These are critical steps in keeping contaminated foods out of the supply chain of foods with allergen-free labels. The conventional methods of chemical assay, DNA-PCR, and enzyme protocols like enzyme-linked immunosorbent assay are effective in allergen detection but slow in providing a response. Most of these methods are incapable of quantifying the level of allergen contamination. There are emerging non-destructive methods that combine the power of sensors and machine learning to provide reliable detection and quantification. This review paper highlights some of the critical information on the types of prevalent food allergens, the mechanism of an allergic reaction in humans, the measure of allergenic sensitivity and eliciting doses, and the conventional and emerging AI-based methods of detection and quantification-the merits and downsides of each type.

Heteroatoms chemical tailoring of aluminum nitrite nanotubes as biosensors for 5-hydroxyindole acetic acid (a biomarker for carcinoid tumors): insights from a computational study

This study aims to elucidate the properties of aluminum nitrite nanotubes (AlNNT) encapsulated with phosphorus (P@AlNNT), sulphur (S@AlNNT), and silicon (Si@AlNNT) heteroatoms for use as biosensors for 5-hydroxyindoleacetic acid (5HIAA).

Chimeric Protein Switch Biosensors

Rapid detection of protein and small-molecule analytes is a valuable technique across multiple disciplines, but most in vitro testing of biological or environmental samples requires long, laborious processes and trained personnel in laboratory settings, leading to long wait times for results and high expenses. Fusion of recognition with reporter elements has been introduced to detection methods such as enzyme-linked immunoassays (ELISA), with enzyme-conjugated secondary antibodies removing one of the many incubation and wash steps. Chimeric protein switch biosensors go further and provide a platform for homogenous mix-and-read assays where long wash and incubation steps are eradicated from the process. Chimeric protein switch biosensors consist of an enzyme switch (the reporter) coupled to a recognition element, where binding of the analyte results in switching the activity of the reporter enzyme on or off. Several chimeric protein switch biosensors have successfully been developed for analytes ranging from small molecule drugs to large protein biomarkers. There are two main formats of chimeric protein switch biosensor developed, one-component and multi-component, and these formats exhibit unique advantages and disadvantages. Genetically fusing a recognition protein to the enzyme switch has many advantages in the production and performance of the biosensor. A range of immune and synthetic binding proteins have been developed as alternatives to antibodies, including antibody mimetics or antibody fragments. These are mainly small, easily manipulated proteins and can be genetically fused to a reporter for recombinant expression or manipulated to allow chemical fusion. Here, aspects of chimeric protein switch biosensors will be reviewed with a comparison of different classes of recognition elements and switching mechanisms.

Hair and Nail-On-Chip for Bioinspired Microfluidic Device Fabrication and Biomarker Detection

The advent of biosensors has tremendously increased our potential of identifying and solving important problems in various domains, ranging from food safety and environmental analysis, to healthcare and medicine. However, one of the most prominent drawbacks of these technologies, especially in the biomedical field, is to employ conventional samples, such as blood, urine, tissue extracts and other body fluids for analysis, which suffer from the drawbacks of invasiveness, discomfort, and high costs encountered in transportation and storage, thereby hindering these products to be applied for point-of-care testing that has garnered substantial attention in recent years. Therefore, through this review, we emphasize for the first time, the applications of switching over to noninvasive sampling techniques involving hair and nails that not only circumvent most of the aforementioned limitations, but also serve as interesting alternatives in understanding the human physiology involving minimal costs, equipment and human interference when combined with rapidly advancing technologies, such as microfluidics and organ-on-a-chip to achieve miniaturization on an unprecedented scale. The coalescence between these two fields has not only led to the fabrication of novel microdevices involving hair and nails, but also function as robust biosensors for the detection of biomarkers, chemicals, metabolites and nucleic acids through noninvasive sampling. Finally, we have also elucidated a plethora of futuristic innovations that could be incorporated in such devices, such as expanding their applications in nail and hair-based drug delivery, their potential in serving as next-generation wearable sensors and integrating these devices with machine-learning for enhanced automation and decentralization.

Recent Advances in the Detection of Food Toxins Using Mass Spectrometry

Edibles are the only source of nutrients and energy for humans. However, ingredients of edibles have undergone many physicochemical changes during preparation and storage. Aging, hydrolysis, oxidation, and rancidity are some of the major changes that not only change the native flavor, texture, and taste of food but also destroy the nutritive value and jeopardize public health. The major reasons for the production of harmful metabolites, chemicals, and toxins are poor processing, inappropriate storage, and microbial spoilage, which are lethal to consumers. In addition, the emergence of new pollutants has intensified the need for advanced and rapid food analysis techniques to detect such toxins. The issue with the detection of toxins in food samples is the nonvolatile nature and absence of detectable chromophores; hence, normal conventional techniques need additional derivatization. Mass spectrometry (MS) offers high sensitivity, selectivity, and capability to handle complex mixtures, making it an ideal analytical technique for the identification and quantification of food toxins. Recent technological advancements, such as high-resolution MS and tandem mass spectrometry (MS/MS), have significantly improved sensitivity, enabling the detection of food toxins at ultralow levels. Moreover, the emergence of ambient ionization techniques has facilitated rapid in situ analysis of samples with lower time and resources. Despite numerous advantages, the widespread adoption of MS in routine food safety monitoring faces certain challenges such as instrument cost, complexity, data analysis, and standardization of methods. Nevertheless, the continuous advancements in MS-technology and its integration with complementary techniques hold promising prospects for revolutionizing food safety monitoring. This review discusses the application of MS in detecting various food toxins including mycotoxins, marine biotoxins, and plant-derived toxins. It also explores the implementation of untargeted approaches, such as metabolomics and proteomics, for the discovery of novel and emerging food toxins, enhancing our understanding of potential hazards in the food supply chain.

Aptasensors: employing molecular probes for precise medical diagnostics and drug monitoring

Accurate detection and monitoring of therapeutic drug levels are vital for effective patient care and treatment management. Aptamers, composed of single-stranded DNA or RNA molecules, are integral components of biosensors designed for both qualitative and quantitative detection of biological samples. Aptasensors play crucial roles in target identification, validation, detection of drug-target interactions and screening potential of drug candidates. This review focuses on the pivotal role of aptasensors in early disease detection, particularly in identifying biomarkers associated with various diseases such as cancer, infectious diseases and cardiovascular disorders. Aptasensors have demonstrated exceptional potential in enhancing disease diagnostics and monitoring therapeutic drug levels. Aptamer-based biosensors represent a transformative technology in the field of healthcare, enabling precise diagnostics, drug monitoring and disease detection.

Development of Photonic Multi-Sensing Systems Based on Molecular Gates Biorecognition and Plasmonic Sensors: The PHOTONGATE Project

This paper presents the concept of a novel adaptable sensing solution currently being developed under the EU Commission-founded PHOTONGATE project. This concept will allow for the quantification of multiple analytes of the same or different nature (chemicals, metals, bacteria, etc.) in a single test with levels of sensitivity and selectivity at/or over those offered by current solutions. PHOTONGATE relies on two core technologies: a biochemical technology (molecular gates), which will confer the specificity and, therefore, the capability to be adaptable to the analyte of interest, and which, combined with porous substrates, will increase the sensitivity, and a photonic technology based on localized surface plasmonic resonance (LSPR) structures that serve as transducers for light interaction. Both technologies are in the micron range, facilitating the integration of multiple sensors within a small area (mm2). The concept will be developed for its application in health diagnosis and food safety sectors. It is thought of as an easy-to-use modular concept, which will consist of the sensing module, mainly of a microfluidics cartridge that will house the photonic sensor, and a platform for fluidic handling, optical interrogation, and signal processing. The platform will include a new optical concept, which is fully European Union Made, avoiding optical fibers and expensive optical components.

Is the use of biosensor in monitoring food quality experiencing an uplift trend over the last 30 years?: A bibliometric analysis

Recently, there has been intense competition among food industries worldwide as they strive to fulfill the ever-growing consumer expectations regarding both the quantity and quality of food. The increasing demand for high-quality food has motivated researchers and academics to constantly innovate and develop real-time and precise tools for monitoring food quality. One such tool that has emerged is biosensors, which have already been widely investigated; however, no bibliometric reviews have discussed biosensor use holistically, comprehensively, and objectively. Therefore, this review aimed to analyze the trend of biosensor publications for monitoring food quality based on the number of documents published from 1991 to 2021, analyze the contribution of various journals, institutions, and cooperation between countries, highlight the most influential authors and articles, and predict the development of this topic. The Method used in this study is bibliometric analysis which consists of four stages, namely data mining from the Scopus database which are limited to data for the last 30 years (1991-2021), refining data, data visualization and interpretation data. There are 604 articles obtained from Scopus and visualization shows that biosensor use for monitoring food quality has significantly increased in the past three decades. Biosensors and Bioelectronics is the leading journal in publishing manuscripts on the topic of biosensors. In terms of the largest contribution, China produced the highest number of publications on related topics, while the United States has the highest collaborations between countries. Moreover, Whitcombe MJ has the most influential articles, while Wang S had the largest number of outputs. The frequently used keywords are "biosensors," "food safety," and "food analysis." These results are important references to determine the state of the art and directions for further investigations.

Sugar Detection in Aqueous Solution Using an SMS Fiber Device

We report on the fabrication and testing of a fiber optics sensor based on multimodal interference effects, which aims at the detection of different types of sweeteners dissolved in water. The device, which has a simple structure, commonly known as the SMS configuration, is built by splicing a segment of commercial-grade, coreless multimode fiber (NC-MMF) between two standard single-mode fibers (SMFs). In this configuration, the evanescent field traveling outside the core of the NC-MMF allows the sensing of the refractive index of the surrounding media, making it possible to detect different levels of sugar concentration. The optical sensor was tested with aqueous solutions of glucose, fructose, and sucrose in the concentration range from 0 wt% to 20 wt% at room temperature. The proposed device exhibits a linear response with a sensitivity of 0.1835 nm/wt% for sucrose, 0.1687 nm/wt% for fructose, and 0.1694 nm/wt% for glucose, respectively, with a sensing resolution of around 0.5 wt%. Finally, we show that, despite having similar concentration behavior, some degree of discrimination between the different sugars can be achieved by assessing their thermo-optical response.

IoT-Enabled Electronic Nose System for Beef Quality Monitoring and Spoilage Detection

Food spoilage is a major concern in the food industry, especially for highly perishable foods such as beef. In this paper, we present a versatile Internet of Things (IoT)-enabled electronic nose system to monitor food quality by evaluating the concentrations of volatile organic compounds (VOCs). The IoT system consists mainly of an electronic nose, temperature/humidity sensors, and an ESP32-S3 microcontroller to send the sensors' data to the server. The electronic nose consists of a carbon dioxide gas sensor, an ammonia gas sensor, and an ethylene gas sensor. This paper's primary focus is to use the system for identifying beef spoilage. Hence, the system performance was examined on four beef samples stored at different temperatures: two at 4 °C and two at 21 °C. Microbial population quantifications of aerobic bacteria, Lactic Acid Bacteria (LAB), and Pseudomonas spp., in addition to pH measurements, were conducted to evaluate the beef quality during a period of 7 days to identify the VOCs concentrations that are associated with raw beef spoilage. The spoilage concentrations that were identified using the carbon dioxide, ammonia, and ethylene sensors were 552 ppm-4751 ppm, 6 ppm-8 ppm, and 18.4 ppm-21.1 ppm, respectively, as determined using a 500 mL gas sensing chamber. Statistical analysis was conducted to correlate the bacterial growth with the VOCs production, where it was found that aerobic bacteria and Pseudomonas spp. are responsible for most of the VOCs production in raw beef.

Electrochemical detection of lactate produced by foodborne presumptive lactic acid bacteria

The detection of lactate is an important indicator of the freshness, stability, and storage stability of products as well as the degree of fermentation in the food industry. In addition, it can be used as a diagnostic tool in patients' healthcare since it is known that the lactate level in blood increases in some pathological conditions. Thus, the determination of lactate level plays an important role in not only the food industry but also in health fields. As a result, biosensor technologies, which are quick, cheap, and easy to use, have become important for lactate detection. In the current study, amperometric lactate biosensors based on lactate oxidase immobilization (with Nafion 5% wt) were designed and the limit of detection, linear range, and sensitivity values were determined to be 31 μM, 50-350 μM, and 0.04 μA μM^-1 cm^-2, respectively. Then, it was used for the measurement of lactic acid that produced by six different and morphologically identified presumptive lactic acid bacteria (LAB) which are isolated from different naturally fermented cheese samples. The biosensors were then used to successfully perform lactate measurements within 3 min for each sample, even though a few of them were out of the limit of detection. Thus, electrochemical biosensors should be used as an alternative and quick solutions for the measurement of lactate metabolites rather than the traditional methods which require long working hours. This is the first study to use a biosensor to measure lactate produced by foodborne LAB in a real sample.

Innovations in the synthesis of graphene nanostructures for bio and gas sensors

Sensors play a significant role in modern technologies and devices used in industries, hospitals, healthcare, nanotechnology, astronomy, and meteorology. Sensors based upon nanostructured materials have gained special attention due to their high sensitivity, precision accuracy, and feasibility. This review discusses the fabrication of graphene-based biosensors and gas sensors, which have highly efficient performance. Significant developments in the synthesis routes to fabricate graphene-based materials with improved structural and surface properties have boosted their utilization in sensing applications. The higher surface area, better conductivity, tunable structure, and atom-thick morphology of these hybrid materials have made them highly desirable for the fabrication of flexible and stable sensors. Many publications have reported various modification approaches to improve the selectivity of these materials. In the current work, a compact and informative review focusing on the most recent developments in graphene-based biosensors and gas sensors has been designed and delivered. The research community has provided a complete critical analysis of the most robust case studies from the latest fabrication routes to the most complex challenges. Some significant ideas and solutions have been proposed to overcome the limitations regarding the field of biosensors and hazardous gas sensors.

Biotechnological advancements towards water, food and medical healthcare: A review

The global health status is highly affected by the growing pace of urbanization, new lifestyles, climate changes, and resource exploitation. Modern technologies pave a promising way to deal with severe concerns toward sustainable development. Herein, we provided a comprehensive review of some popular biotechnological advancements regarding the progress achieved in water, food, and medicine, as the most substantial fields related to public health. The emergence of novel organic/inorganic materials has brought about significant improvement in conventional water treatment techniques, anti-fouling approaches, anti-microbial agents, food processing, biosensors, drug delivery systems, and implants. Particularly, a growing interest has been devoted to nanomaterials and their application for developing novel structures or improving the characteristics of standard components. Also, bioinspired materials have been widely used to improve the performance, efficiency, accuracy, stability, safety, and cost-effectiveness of traditional systems. On the other side, the fabrication of innovative devices for precisely monitoring and managing various ecosystem and human health issues is of great importance. Above all, exceptional advancements in designing ion-selective electrodes (ISEs), microelectromechanical systems (MEMs), and implantable medical devices have altered the future landscape of environmental and biomedical research. This review paper aimed to shed light on the wide-ranging materials and devices that have been developed for health applications and mainly focused on the impact of nanotechnology in this field.

Nanomaterial-Based Fluorescent Biosensor for Food Safety Analysis

Food safety issues have become a major threat to public health and have garnered considerable attention. Rapid and effective detection methods are crucial for ensuring food safety. Recently, nanostructured fluorescent materials have shown considerable potential for monitoring the quality and safety of food because of their fascinating optical characteristics at the nanoscale. In this review, we first introduce biomaterials and nanomaterials for food safety analysis. Subsequently, we perform a comprehensive analysis of food safety using fluorescent biosensors based on nanomaterials, including mycotoxins, heavy metals, antibiotics, pesticide residues, foodborne pathogens, and illegal additives. Finally, we provide new insights and discuss future approaches for the development of food safety detection, with the aim of improving fluorescence detection methods for the practical application of nanomaterials to ensure food safety and protect human health.

Challenges in assessing the quality of fruit juices: Intervening role of biosensors

The quality of packaged fruit juices is affected during their processing, packaging and storage that might cause deteriorative biological, chemical and physical alterations. Consumption of spoiled juices, either from biological or non-biological sources can pose a potential health hazard for the consumers. Sensitive and reliable methods are required to ensure the quality of fruit juices. Standard analytical methods such as chromatography, spectrophotometry, electrophoresis and titration, that require sophisticated equipment and expertise, are traditionally used to assess the quality of fruit juices. Using biosensors, that are simple, portable and rapid presents a promising alternative to the tedious analytical methods for the detection of various degradation and spoilage indicators formed in the packaged fruit juices. Here, we review the challenges in maintaining the quality of fruit juices and the recent developments in techniques and biosensors for quick analysis of fruit juice components.

A novel label-free colorimetric polyA aptasensing approach based on cationic polymer and silver nanoparticles for detection of tobramycin in milk

In this study, a novel colorimetric bioassay method was developed for the sensitive determination of tobramycin (TOB). To detect TOB, silver nanoparticles (AgNPs) were decorated with TOB-specific aptamers (apt), and positively charged poly diallyl dimethyl ammonium chloride (PDDA) was used. As long as tobramycin is not present in the assay system, PDDA can coalesce with the aptamer, and AgNPs would remain stable (λmax = 400 nm) in the dispersed system against PDDA-induced aggregation. When TOB is added, aptamer can bind to the compound, which leads to release of PDDA and subsequent aggregation of AgNPs (λmax = 540 nm). This remarkable change, as a colorimetric analytics signal, can be used for quantitative analysis of TOB. TOB can be detected by this highly sensitive colorimetric aptasensor with a limit of detection (LOD) of 70 pM. Furthermore, TOB can be detected with the naked eye at concentrations above 1 nM.

Nano-biocatalysts for food applications; immobilized enzymes within different nanostructures

The rapid progress in modern technologies and paying more attention to food safety has prompted new green technologies superior than chemical methods in the food industry. In this regard, enzymes can decrease the usage of chemical reactions but they are sensitive to environmental effects (pH and temperature). In addition, enzymes are scarcely possible to be reused. Consequently, their application as natural catalysts is restricted. Using nanotechnology and the possibility of enzyme immobilization on nanomaterials has led to nanobiocatalysts, resulting from the integration of nanotechnology and biotechnology. Nanocarriers have individual features like nanoscale size, excellent surface/volume ratio, and diversity in construction to improve the activity, efficiency, stability, and storage stability of enzymes. Nanobiocatolysts have a wide range of applications in purification, extraction, clarification, production, and packaging of various products in the food industry. Furthermore, the application of nanobiocatalysts to identify specific components of food contaminants such as microorganisms or their metabolites, heavy metals, antibiotics, and residual pesticides has been successful due to the high accuracy of detection. This review investigates the integration of nanotechnology and food enzymes, the nanomaterials used to create nanobiocatalysts and their application, along with the possible risks and legal aspects of nanomaterials in food bioprocesses.

Immobilization of Streptavidin on a Plasmonic Au-TiO2 Thin Film towards an LSPR Biosensing Platform

Optical biosensors based on localized surface plasmon resonance (LSPR) are the future of label-free detection methods. This work reports the development of plasmonic thin films, containing Au nanoparticles dispersed in a TiO₂ matrix, as platforms for LSPR biosensors. Post-deposition treatments were employed, namely annealing at 400 °C, to develop an LSPR band, and Ar plasma, to improve the sensitivity of the Au-TiO₂ thin film. Streptavidin and biotin conjugated with horseradish peroxidase (HRP) were chosen as the model receptor–analyte, to prove the efficiency of the immobilization method and to demonstrate the potential of the LSPR-based biosensor. The Au-TiO₂ thin films were activated with O₂ plasma, to promote the streptavidin immobilization as a biorecognition element, by increasing the surface hydrophilicity (contact angle drop to 7°). The interaction between biotin and the immobilized streptavidin was confirmed by the detection of HRP activity (average absorbance 1.9 ± 0.6), following a protocol based on enzyme-linked immunosorbent assay (ELISA). Furthermore, an LSPR wavelength shift was detectable (0.8 ± 0.1 nm), resulting from a plasmonic thin-film platform with a refractive index sensitivity estimated to be 33 nm/RIU. The detection of the analyte using these two different methods proves that the functionalization protocol was successful and the Au-TiO₂ thin films have the potential to be used as an LSPR platform for label-free biosensors.

Analysis of Alternative Shelf Life-Extending Protocols and Their Effect on the Preservation of Seafood Products

Seafood is essential to a healthy and varied diet due to its highly nutritious characteristics. However, seafood products are highly perishable, which results in financial losses and quality concerns for consumers and the industry. Due to changes in consumer concerns, demand for healthy products has increased. New trends focusing on reducing synthetic preservatives require innovation and the application of additional or alternative strategies to extend the shelf life of this type of product. Currently, refrigeration and freezing storage are the most common methods for fish preservation. However, refrigeration alone cannot provide long shelf-life periods for fish, and freezing worsens sensorial characteristics and consumer interest. Therefore, the need to preserve seafood for long periods without exposing it to freezing temperatures exists. This review focuses on the application of other approaches to seafood products, such as biodegradable films and coating technology; superchilling; irradiation; high-pressure processing; hyperbaric storage; and biopreservation with lactic acid bacteria, bacteriocins, or bacteriophages. The efficiency of these techniques is discussed based on their impact on microbiological quality, sensorial degradation, and overall preservation of the product’s nutritional properties. Although these techniques are already known, their use in the industrial processing of seafood is not widespread. Thus, the novelty of this review is the aggregation of recent studies on shelf life extension approaches, which provide useful information for the selection of the most appropriate technology and procedures and industrial innovation. Despite the fact that all techniques inhibit or delay bacterial proliferation and product decay, an undesirable sensory impact may occur depending on the treatment conditions. Although no technique appears to replace refrigeration, the implementation of additional treatments in the seafood processing operation could reduce the need for freezing, extending the shelf life of fresh unfrozen products.

Emerging vistas on pesticides detection based on electrochemical biosensors - An update

Organophosphates and carbamates pesticides are widely used to increase crop production globally causing a threat to human health and the environment. A variety of pesticides are applied during different stages of vegetable production. Therefore, monitoring the presence of pesticide residues in food and soil has great relevance to sensitive pesticide detection through distinct determination methods that are urgently required. Conventional techniques for the detection of pesticides have several limitations that can be overcome by the development of highly sensitive, fast, reliable and easy-to-use electrochemical biosensors. Herein, we describe the types of biosensors with the main focus on electrochemical biosensors fabricated for the detection of OPPs and carbamates pesticides. An overview of conventional techniques employed for pesticide detection is also discussed. This review aims to provide a glance of recently developed biosensors for some common pesticides like chlorpyrifos, malathion, parathion, paraoxon, and carbaryl which are present in food and environment samples.

Discovery of Two Novel Oxidases Using a High-Throughput Activity Screen

Discovery of novel enzymes is a challenging task, yet a crucial one, due to their increasing relevance as chemical catalysts and biotechnological tools. In our work we present a high-throughput screening approach to discovering novel activities. A screen of 96 putative oxidases with 23 substrates led to the discovery of two new enzymes. The first enzyme, N-acetyl-D-hexosamine oxidase (EC 1.1.3.29) from Ralstonia solanacearum, is a vanillyl alcohol oxidase-like flavoprotein displaying the highest activity with N-acetylglucosamine and N-acetylgalactosamine. Before our discovery of the enzyme, its activity was an orphan one - experimentally characterized but lacking the link to amino acid sequence. The second enzyme, from an uncultured marine euryarchaeota, is a long-chain alcohol oxidase (LCAO, EC 1.1.3.20) active with a range of fatty alcohols, with 1-dodecanol being the preferred substrate. The enzyme displays no sequence similarity to previously characterised LCAOs, and thus is a completely novel representative of a protein with such activity.

Development, Optimization, Characterization, and Application of Electrochemical Biosensors for Detecting Nickel Ions in Food

Nickel is naturally present in drinking water and many dietary items, which expose the general population to nickel ingestion. This heavy metal can have a variety of harmful health effects, causing allergies and skin disorders (i.e., dermatitis), lung, cardiovascular, and kidney diseases, and even certain cancers; therefore, nickel detection is important for public health. Recent innovations in the development of biosensors have demonstrated they offer a powerful new approach over conventional analytical techniques for the identification and quantification of user-defined compounds, including heavy metals such as nickel. We optimized five candidate nickel-biosensing receptors, and tested each for efficiency of binding to immobilization elements on screen-printed electrodes (SPEs). We characterized the application of nickel-detecting biosensors with four different cultivated vegetables. We analyzed the efficiency of each nickel-detecting biosensor by potentiostat and atomic absorption spectrometry and compared the results from the sample analytes. We then analyzed the performance characteristics and responses of assembled biosensors, and show they are very effective at measuring nickel ions in food, especially with the urease-alginate biosensor affixed to silver SPEs, measured by cyclic voltammetry (sensitivity-2.1921 µA Mm-1 cm-2 and LOD-0.005 mg/L). Given the many advantages of biosensors, we describe an optimization pipeline approach to the application of different nickel-binding biosensors for public health, nutrition, and consumer safety, which are very promising.

Attomolar analyte sensing techniques (AttoSens): a review on a decade of progress on chemical and biosensing nanoplatforms

Detecting the ultra-low abundance of analytes in real-life samples, such as biological fluids, water, soil, and food, requires the design and development of high-performance biosensing modalities. The breakthrough efforts from the scientific community have led to the realization of sensing technologies that measure the analyte's ultra-trace level, with relevant sensitivity, selectivity, response time, and sampling efficiency, referred to as Attomolar Analyte Sensing Techniques (AttoSens) in this review. In an AttoSens platform, 1 aM detection corresponds to the quantification of 60 target analyte molecules in 100 μL of sample volume. Herein, we review the approaches listed for various sensor probe design, and their sensing strategies that paved the way for the detection of attomolar (aM: 10^-18 M) concentration of analytes. A summary of the technological advances made by the diverse AttoSens trends from the past decade is presented.

Smartphone-based technology for nanomolecular detection of aflatoxin B1 by aptamer-conjugated magnetic nanoparticles

The need for a healthy market in the rapid and accurate screening of a variety of pathogenic agents and toxins in the environment and food has led to an increase in the development of new biosensors, which have ideal characteristics, such as high sensitivity and specificity with rapid detection and simple preparation of the sample. Among the food contaminants, mycotoxins have been identified as a major challenge for the food industry, and rapid and accurate detection has attracted the attention of food inspection and monitoring organisations. In this study, a nanomolecular detection method is described using aflatoxin B1 (AFB1)-specific aptamers attached to streptavidin-coated magnetic nanoparticles. A prominent feature of the AFB1-specific aptamers is a guanine-rich (G-rich) sequence with a G-quadruplex structure after capturing AFB1 molecules and mimicking peroxidase activity. The enzymatic reaction evaluated in the presence of chromogenic substrate and measurement is done by a smartphone-specific application for colorimetric measurement. The results indicated that the assay could measure AFB1 in rice, flour, seed, maize, and pistachio. In addition, the application of hybrid nanomaterial technology resulting from the binding of biotin-labelled aptamers to the surface of streptavidin-coated magnetic nanoparticles minimises preparation and treatment of samples, improves results, and consequently reduces false negative and positive responses in the detection field. This study may eventually lead to the design and development of a fast, sensitive, specific, and on-site AFB1-based nanomolecular colorimetric detection system via a smartphone-based application that can be readily accessible to all applicants, from professionals to manufacturers of foodstuffs.