Biosensors for the analysis of microbiological and chemical contaminants in food

Increases in food production and the ever-present threat of food contamination from microbiological and chemical sources have led the food industry and regulators to pursue rapid, inexpensive methods of analysis to safeguard the health and safety of the consumer. Although sophisticated techniques such as chromatography and spectrometry provide more accurate and conclusive results, screening tests allow a much higher throughput of samples at a lower cost and with less operator training, so larger numbers of samples can be analysed. Biosensors combine a biological recognition element (enzyme, antibody, receptor) with a transducer to produce a measurable signal proportional to the extent of interaction between the recognition element and the analyte. The different uses of the biosensing instrumentation available today are extremely varied, with food analysis as an emerging and growing application. The advantages offered by biosensors over other screening methods such as radioimmunoassay, enzyme-linked immunosorbent assay, fluorescence immunoassay and luminescence immunoassay, with respect to food analysis, include automation, improved reproducibility, speed of analysis and real-time analysis. This article will provide a brief footing in history before reviewing the latest developments in biosensor applications for analysis of food contaminants (January 2007 to December 2010), focusing on the detection of pathogens, toxins, pesticides and veterinary drug residues by biosensors, with emphasis on articles showing data in food matrices. The main areas of development common to these groups of contaminants include multiplexing, the ability to simultaneously analyse a sample for more than one contaminant and portability. Biosensors currently have an important role in food safety; further advances in the technology, reagents and sample handling will surely reinforce this position.     

The role of biosensors in the detection of emerging infectious diseases

Global biosecurity threats such as the spread of emerging infectious diseases (i.e., avian influenza, SARS, Hendra, Nipah, etc.) and bioterrorism have generated significant interest in recent years. There is considerable effort directed towards understanding and negating the proliferation of infectious diseases. Biosensors are an attractive tool which have the potential to detect the outbreak of a virus and/or disease. Although there is a host of technologies available, either commercially or in the scientific literature, the development of biosensors for the detection of emerging infectious diseases (EIDs) is still in its infancy. There is no doubt that the glucose biosensor, the gene chip, the protein chip, etc. have all played and are still playing a significant role in monitoring various biomolecules. Can biosensors play an important role for the detection of emerging infectious diseases? What does the future hold and which biosensor technology platform is suitable for the real-time detection of infectious diseases? These and many other questions will be addressed in this review. The purpose of this review is to present an overview of biosensors particularly in relation to EIDs. It provides a synopsis of the various types of biosensor technologies that have been used to detect EIDs, and describes some of the technologies behind them in terms of transduction and bioreceptor principles.     

Biosensors for Biogenic Amines: The Present State of Art Mini-Review

The analysis of biogenic amines in fresh and processed food is of great importance not only for the potential risk these compounds have on human health, but also because these amines can perform as chemical indicators of food quality and enable the assessment of food processing conditions and/or microbial contamination.

A good option for a rapid detection of biogenic amines is the application of biosensors, as these devices enable the obtainment of results in a few minutes without pretreatment of the analyzed material. Biosensors for biogenic amines comprise various combinations of different enzymes for selective biorecognition and signal transduction systems and are based on different signal mechanisms. The present review gives a condensed overview of the recent developments and issues in the construction of biosensors for the detection of most common biogenic amines found in food and other protein-containing material.     

New advances in electrochemical biosensors for the detection of toxins: Nanomaterials,magnetic beads and microfluidics systems. A review

The use of nanotechnology in bioanalytical devices has special advantages in the detection of toxins of interest in food safety and environmental applications. The low levels to be detected and the small size of toxins justify the increasing number of publications dealing with electrochemical biosensors, due to their high sensitivity and design versatility. The incorporation of nanomaterials in their development has been exploited to further increase their sensitivity, providing simple and fast devices, with multiplexed capabilities. This paper gives an overview of the electrochemical biosensors that have incorporated carbon and metal nanomaterials in their configurations for the detection of toxins. Biosensing systems based on magnetic beads or integrated into microfluidics systems have also been considered because of their contribution to the development of compact analytical devices. The roles of these materials, the methods used for their incorporation in the biosensor configurations as well as the advantages they provide to the analyses are summarised.     

Biosensors for environmental monitoring A global perspective

The intention of this article is to reflect the advances and describe the trends on biosensors for environmental applications. Biosensors are useful analytical tools for environmental monitoring, capable of providing results in real time, simple to use, portable and cost-effective. Some examples of biosensors in advanced stage of development, which have been applied to real samples, as well as of commercial devices, are given. Biosensors designed for measurement of either specific chemicals or their biological effects, such as toxicity biosensors and endocrine effect biosensors, are discussed. This overview also addresses the support provided by public institutions for biosensor research in the USA, Japan and, especially, in Europe. Future prospects of biosensor technology, with special emphasis in the development of new sensing elements, are foreseen.     

Vitamin and pseudovitamin analysis with biosensors in food products--a review

Biosensors are becoming increasingly important in the food industry for application in safety and quality control among routinely used techniques such as microbiology, chromatography, or specific enzymatic methods. Biosensors offer advantages as alternatives to conventional methods because of their inherent specificity, simplicity, and rapid response. This article presents a short review of vitamin and pseudovitamin analysis techniques using biosensor technology as applied in the food industries, with particular attention to immobilization techniques of biorecognition elements, transducers, an overview of vitamin biosensors, and some future trends.     

Electromechanical biosensors for pathogen detection

Rapid and sensitive detection of pathogen is critical for public health, defense and security. Methods such as culture and immunoassays, though highly selective and accurate, are time-consuming and not sufficient for fast decision-making in many situations. Biosensors have been developed to meet the challenges in pathogen detection. This article reviews the development and application of electromechanical biosensors for pathogen detection. It covers the most commonly used electromechanical biosensor systems, specifically quartz crystal microbalances, cantilever sensors and surface wave acoustic sensors. Sensing principles, immobilization of biorecognition elements, and applications to the detection of pathogens in food and water samples are sequentially discussed.

In Vivo Electrochemical Biosensors for Reactive Oxygen Species Detection: A Mini-Review

Due to the significance of reactive oxygen species (ROS) in numerous physiological processes including pathogen response, apoptosis, and induction of defense genes, various methods have been developed for their quantitative analysis. However, the conventional methods using exogenous tracers lack the capability to conduct real-time in vivo measurements. The electrochemical biosensors have shown their potentials for in vivo applications with the rapid and reagentless detection processes. In this article, electrochemical biosensors that are capable of making in vivo ROS detections are reviewed. The different configurations of these biosensors with corresponding strategies to enhance sensitivity and selectivity are discussed in detail. With further studies to promote the biosensor performance, these devices promise to provide more facile ways for ROS research in life sciences.     

Biosensors as a tool for the antioxidant status evaluation

Antioxidants are one of the main ingredients that protect food attributes by preventing oxidation that occurs during processing, distribution and end preparation of food. Physiological antioxidant protection involves a variety of chemical system of endogenous and exogenous origin in a multiplicity of pathways. Associate to this, researches have been directed in the development of methods as biosensors that can characterize antioxidants capable of removing harmful radicals in living organisms in an adequate way. Biosensors have represented a broad area of technology useful for environmental, food monitoring, clinical applications and can represent a good alternative method to evaluate the antioxidant status.The demonstration of the highlighted current application of biosensor as a potential tool to evaluate the antioxidant status is the main aim of this review.     

金属有机骨架复合材料生物传感器检测肿瘤标志物的应用进展

生物传感器是传统肿瘤标志物检测方法的有效替代方法,而基于金属有机骨架(MOF)复合材料的生物传感器在肿瘤标志物检测方面具有速度快、灵敏度高、检出限低、成本低等优点。综述了MOF及其复合材料的分类,介绍了基于MOF复合材料的生物传感器在检测肿瘤标志物方面的应用进展,并对基于MOF复合材料的生物传感器未来发展趋势进行了展望。     

Recent development in chitosan nanocomposites for surface‐based biosensor applications

Recent years have witnessed ever expanding use of biosensors in the fields of environmental monitoring, homeland security, pharmaceutical, food and bioprocessing, and agricultural industries. To produce effective and reliable biosensors, good quality immobilization of biological recognition elements is critical. Chitosan and its nanocomposites emerge as an excellent immobilization matrix on biosensor surface. As a natural polysaccharide, chitosan has many useful characteristics, such as high permeability and mechanical strength, biocompatibility and non‐toxicity, availability, and low cost. Due to the presence of amino and hydroxyl groups on chitosan, chitosan can easily crosslink with a variety of nanomaterials. This investigation of chitosan nanocomposite‐based biosensors presents recent development and innovations in the preparation of chitosan nanocomposites in coordination with biosensors for various bio‐detection applications, including chitosan nanocomposites formed with carbon nanomaterials, various inorganic and biological complexes. These chitosan nanocomposite based biosensors have demonstrated good sensitivity selectivity and stability for the detection of different types of targets ranging from glucose, proteins, DNAs, small biomolecules to bacteria. It is in our hope that this review will offer guidance for the development of novel biosensors and open up opportunities in the field of biosensor research.     

Application of nanomaterials in microbial-cell biosensor constructions

Microbial cell biosensors, where cells are in direct connection with a transducer enabling quantitative and qualitative detection of an analyte, are very promising analytical tools applied mainly for assays in the environmental field, food industry or biomedicine. Microbial cell biosensors are an excellent alternative to conventional analytical methods due to their specificity, rapid detection and low cost of analysis. Nowadays, nanomaterials are often used in the construction of biosensors to improve their sensitivity and stability. In this review, the combination of microbial and other individual cells with different nanomaterials (carbon nanotubes, graphene, gold nanoparticles, etc.) for the construction of biosensors is described and their applications are provided as well.     

Recent advances in ZnO nanostructures and thin films for biosensor applications: Review

Biosensors have shown great potential for health care and environmental monitoring. The performance of biosensors depends on their components, among which the matrix material, i.e., the layer between the recognition layer of biomolecule and transducer, plays a crucial role in defining the stability, sensitivity and shelf-life of a biosensor. Recently, zinc oxide (ZnO) nanostructures and thin films have attracted much interest as materials for biosensors due to their biocompatibility, chemical stability, high isoelectric point, electrochemical activity, high electron mobility, ease of synthesis by diverse methods and high surface-to-volume ratio. ZnO nanostructures have shown the binding of biomolecules in desired orientations with improved conformation and high biological activity, resulting in enhanced sensing characteristics. Furthermore, compatibility with complementary metal oxide semiconductor technology for constructing integrated circuits makes ZnO nanostructures suitable candidate for future small integrated biosensor devices. This review highlights recent advances in various approaches towards synthesis of ZnO nanostructures and thin films and their applications in biosensor technology.     

电化学酶传感器在环境污染监测中的应用

电化学酶传感器是一种应用广泛的生物传感器,它将酶及其底物相互作用的特异性与电化学的强大分析功能相结合,已经被广泛应用于药理学、临床、食品、农业以及环境监测中。制备电化学酶传感器的关键步骤是酶的固定化,选择用于制备电化学酶传感器的合适的酶固定化方法,在传感器电子转移动力学、稳定性和重现性等方面起着主要作用。本文在阐述电化学酶传感器工作原理的基础上,简要介绍了用于电化学酶传感器制备过程中的酶固定化方法,重点讨论了电化学酶传感器在监测环境中广泛存在的有机污染物、无机污染物和重金属等方面的应用,并对电化学酶传感器的发展方向进行了展望。     

Biosensors for effective environmental and agrifood protection and commercialization: from research to market

Biosensors are projected to find many applications due to their high selectivity and sensitivity, rapid reaction, economy and ease of handling in field measurements. Even though biosensors for a wide range of environmental pollutants have been extensively reported in the literature, the decision to develop a suitable biosensing system that can be approved by a regulatory perspective for environmental applications is fraught with technical issues. These issues mainly concern the biological recognition element, the physico-chemical transducer and the interfaces between the biological and the physical components, but also aspects of fluidics, electronics, and software for data processing. This article reviews methods together with a process to move biosensor technology from research laboratories to market, focusing as a case in point on challenges and possible opportunities in the development of photosynthetic-based biosensors for environmental applications.     

Microfluidics for food, agriculture and biosystems industries

Microfluidics, a rapidly emerging enabling technology has the potential to revolutionize food, agriculture and biosystems industries. Examples of potential applications of microfluidics in food industry include nano-particle encapsulation of fish oil, monitoring pathogens and toxins in food and water supplies, micro-nano-filtration for improving food quality, detection of antibiotics in dairy food products, and generation of novel food structures. In addition, microfluidics enables applications in agriculture and animal sciences such as nutrients monitoring and plant cells sorting for improving crop quality and production, effective delivery of biopesticides, simplified in vitro fertilization for animal breeding, animal health monitoring, vaccination and therapeutics. Lastly, microfluidics provides new approaches for bioenergy research. This paper synthesizes information of selected microfluidics-based applications for food, agriculture and biosystems industries.     

Surface plasmon resonance sensing of nucleic acids: A review

Biosensors based on surface plasmon resonance (SPR) have become a central tool for the investigation and quantification of biomolecules and their interactions. Nucleic acids (NAs) play a vital role in numerous biological processes and therefore have been one of the major groups of biomolecules targeted by the SPR biosensors. This paper discusses the advances of NA SPR biosensor technology and reviews its applications both in the research of molecular interactions involving NAs (NA–NA, NA–protein, NA–small molecule), as well as for the field of bioanalytics in the areas of food safety, medical diagnosis and environmental monitoring.     

Microbial biosensors

A microbial biosensor is an analytical device that couples microorganisms with a transducer to enable rapid, accurate and sensitive detection of target analytes in fields as diverse as medicine, environmental monitoring, defense, food processing and safety. The earlier microbial biosensors used the respiratory and metabolic functions of the microorganisms to detect a substance that is either a substrate or an inhibitor of these processes. Recently, genetically engineered microorganisms based on fusing of the lux, gfp or lacZ gene reporters to an inducible gene promoter have been widely applied to assay toxicity and bioavailability. This paper reviews the recent trends in the development and application of microbial biosensors. Current advances and prospective future direction in developing microbial biosensor have also been discussed.