Stabilized Lipid Membrane Based Biosensors with Incorporated Enzyme for Repetitive Uses

Advanced lipid based biosensors for food analysis

The investigation of lipid films for the construction of nanosensors has recently given the opportunity to manufacture devices to selectively determine a wide range of food toxicants. Biosensor miniaturization using recent advances in nanotechnology has given the opportunity to investigate novel techniques to immobilize a wide range of enzymes, antibodies and receptors within the lipid film. This chapter reviews novel revent platforms in nanobiosensors based on lipid membranes that are used in food chemistry to determine various food toxicants. Examples of applications are described with an emphasis on novel systems, sensing techniques and nanotechnology-based transduction schemes. The compounds that can be monitored are insecticides, pesticides, herbicides, metals, toxins, hormones, etc. Finally, limitations and future prospects are presented herein on the evaluation/validation and eventually commercialization of the proposed sensors.

Recent Lipid Membrane-Based Biosensing Platforms

The investigation of lipid films for the construction of biosensors has recently given the opportunity to manufacture devices to selectively detect a wide range of food toxicants, environmental pollutants, and compounds of clinical interest. Biosensor miniaturization using nanotechnological tools has provided novel routes to immobilize various “receptors” within the lipid film. This chapter reviews and exploits platforms in biosensors based on lipid membrane technology that are used in food, environmental, and clinical chemistry to detect various toxicants. Examples of applications are described with an emphasis on novel systems, new sensing techniques, and nanotechnology-based transduction schemes. The compounds that can be monitored are insecticides, pesticides, herbicides, metals, toxins, antibiotics, microorganisms, hormones, dioxins, etc.

The Application of Lipid Membranes in Biosensing

The exploitation of lipid membranes in biosensors has provided the ability to reconstitute a considerable part of their functionality to detect trace of food toxicants and environmental pollutants. This paper reviews recent progress in biosensor technologies based on lipid membranes suitable for food quality monitoring and environmental applications. Numerous biosensing applications based on lipid membrane biosensors are presented, putting emphasis on novel systems, new sensing techniques, and nanotechnology-based transduction schemes. The range of analytes that can be currently using these lipid film devices that can be detected include, insecticides, pesticides, herbicides, metals, toxins, antibiotics, microorganisms, hormones, dioxins, etc. Technology limitations and future prospects are discussed, focused on the evaluation/validation and eventually commercialization of the proposed lipid membrane-based biosensors.

Application of Biosensors Based on Lipid Membranes for the Rapid Detection of Toxins

Lipid assemblies in the form of two dimensional films have been used extensively as biosensing platforms. These films exhibit certain similarities with cell membranes, thus providing a suitable means for the immobilization of proteinaceous moieties and, further, a number of intrinsic signal amplification mechanisms. Their implementation in the detection of toxins yielded reliable and fast detectors for in field analyses of environmental and clinical samples. Some examples are presented herein, including aflatoxin and cholera toxin detection. The conditions and parameters that determine the analytical specifications of the lipid membrane sensors are discussed, advantages and technology bottlenecks are reviewed, and possible further developments are highlighted.

Novel Biosensors for the Rapid Detection of Toxicants in Foods

The modern environmental and food analysis requires sensitive, accurate, and rapid methods. The growing field of biosensors represents an answer to this demand. Unfortunately, most biosensor systems have been tested only on distilled water or buffered solutions, although applications to real samples are increasingly appearing in recent years. In this context, biosensors for potential food applications continue to show advances in areas such as genetic modification of enzymes and microorganisms, improvement of recognition element immobilization, and sensor interfaces. This chapter investigates the progress in the development of biosensors for the rapid detection of food toxicants for online applications. Recent progress in nanotechnology has produced affordable, mass-produced devices, and to integrate these into components and systems (including portable ones) for mass market applications for food toxicants monitoring. Sensing includes chemical and microbiological food toxicants, such as toxins, insecticides, pesticides, herbicides, microorganisms, bacteria, viruses and other microorganisms, phenolic compounds, allergens, genetically modified foods, hormones, dioxins, etc. Therefore, the state of the art of recent advances and future targets in the development of biosensors for food monitoring is summarized as follows: biosensors for food analysis will be highly sensitive, selective, rapidly responding, real time, massively parallel, with no or minimum sample preparation, and platform suited to portable and handheld nanosensors for the rapid detection of food toxicants for online uses even by nonskilled personnel.

Lipid Membrane Nanosensors for Environmental Monitoring: The Art, the Opportunities, and the Challenges

The advent of nanotechnology has brought along new materials, techniques, and concepts, readily adaptable to lipid membrane-based biosensing. The transition from micro-sensors to nano-sensors is neither straightforward nor effortless, yet it leads to devices with superior analytical characteristics: ultra-low detectability, small sample volumes, better capabilities for integration, and more available bioelements and processes. Environmental monitoring remains a complicated field dealing with a large variety of pollutants, several decomposition products, or secondary chemicals produced ad hoc in the short- or medium term, many sub-systems affected variously, and many processes largely unknown. The new generation of lipid membranes, i.e., nanosensors, has the potential for developing monitors with site-specific analytical performance and operational stability, as well as analyte-tailored types of responses. This review presents the state-of-the art, the opportunities for niche applicability, and the challenges that lie ahead.

Protein-Based Graphene Biosensors: Optimizing Artificial Chemoreception in Bilayer Lipid Membranes

Proteinaceous moieties are critical elements in most detection systems, including biosensing platforms. Their potential is undoubtedly vast, yet many issues regarding their full exploitation remain unsolved. On the other hand, the biosensor formats with the higher marketability probabilities are enzyme in nature and electrochemical in concept. To no surprise, alternative materials for hosting catalysis within an electrode casing have received much attention lately to demonstrate a catalysis-coated device. Graphene and ZnO are presented as ideal materials to modify electrodes and biosensor platforms, especially in protein-based detection. Our group developed electrochemical sensors based on these nanomaterials for the sensitive detection of cholesterol using cholesterol oxidase incorporated in stabilized lipid films. A comparison between the two platforms is provided and discussed. In a broader sense, the not-so-remote prospect of quickly assembling a protein-based flexible biosensing detector to fulfill site-specific requirements is appealing to both university researchers and industry developers.

Potentiometric cholesterol biosensing application of graphene electrode with stabilized polymeric lipid membrane

Abstract A novel potentiometric cholesterol biosensor has been fabricated through the immobilization of the stabilized polymeric lipid membrane onto graphene electrode. The stabilized polymeric lipid membrane is composed of cholesterol oxidase enzyme and polymerization mixture; which holds paramount influence on the properties of the cholesterol biosensor. The presented biosensor reveals an appreciable reproducibility, good selectivity and high sensing capability with a linear slope curve of ∼64 mV per decade. The strong biocompatibility among stabilized polymeric lipid membranes and human biofluids provides the possibility to use for real blood samples and other biological applications. Graphical abstract

Preparation of a selective receptor for carbofuran for the development of a simple optical spot test for its rapid detection using stabilized in air lipid films with incorporated receptor

The present technique describes the preparation of a selective receptor for carbofuran and the development of a simple sensitive spot optical test for the rapid one-shot detection of carbofuran using stabilized lipid films supported on a methacrylate polymer on a glass fiber filter with incorporated artificial receptor. The selective receptor was synthesized by a chemical reaction using a resorcin[4]arene receptor by transforming all the -OH groups into phosphoryl groups. The lipid films without this receptor provided fluorescence under a UV lamp. The use of the receptor in these films quenched this fluorescence and the colour became similar to that of the filters without the lipid films. A drop of aqueous solution of carbofuran provided a "switching on" of the fluorescence which allows the rapid detection of this insecticide at the levels of 10(-9)M concentrations. The effect of potent interferences included a wide range of compounds. The results showed no interferences from these compounds in concentration levels usually found in real samples. The effect of interference of proteins and lipids was also examined. The reproducibility of the method was checked in about 100 samples and all of them were found to provide similar results. The device was tested/evaluated in real samples of fruits, vegetables and dairy products. Note that the colours of the filters remain stable for periods of more than 2 months.