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.

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.

Innovation in biotechnology: moving from academic research to product development--the case of biosensors

The fast pace of technological change in the biotechnology industry and the market demands require continuous innovation, which, owing to the science base of the sector, derives from academic research through a transformation process that converts science-oriented knowledge to marketable products. There appear to be some inherent difficulties in transforming directly the knowledge output of academic research to industrial use. The purpose of this article is to examine certain transition mechanisms from monodisciplinary academic isolation (curiosity-driven and internal-worth innovation) to university-industry alliances (market-driven and public-worth innovation) through inter-organizational multidisciplinary collaboration and contextualize the analysis with the case of biosensors. While the majority of literature on the subject studies the channels of knowledge transfer as determinants of alliance success (transferor/transferee interactions), either from the university side (science base) or the industry side (market base), this article focuses on the transferable (technology base) and how it can be strategically modeled and managed by the industry to promote innovation. Based on the valuable lessons learnt from the biosensor paradigm, the authors argue that strategic industry choices deal primarily with the best stage/point to intersect and seize the university output, implanting the required element of marketability that will transform an idea to a viable application. The authors present a methodological approach for accelerating the knowledge transfer from the university to industry aiming at the effective transition of science to products through a business model reconfiguration.

Investigation of interactions of a resorcin[4]arene receptor with bilayer lipid membranes (BLMs) for the electrochemical biosensing of mixtures of dopamine and ephedrine

The present article investigates the interactions of a resorcin[4]arene receptor with planar bilayer lipid membranes (BLMs) that can be used for the electrochemical detection of dopamine and ephedrine. BLMs were composed of egg phosphatidylcholine and 35% (w/w) dipalmitoyl phosphatidic acid in which the receptor was incorporated. These BLMs modified with the resorcin[4]arene receptor can be used as one-shot sensors for the direct electrochemical sensing of these energizing-stimulating substances. The interactions of these compounds with the lipid membranes were found to be electrochemically transduced in the form of a transient current signal with a duration of seconds, which reproducibly appeared within 8 and 20 s after exposure of the membranes to dopamine and ephedrine, respectively. The response time for BLMs without the receptor for dopamine was about 3 min, whereas no signals were obtained for ephedrine in the absence of the receptor. The mechanism of signal generation was investigated by differential scanning calorimetric studies. These studies revealed that the adsorption of the receptor is through the hydrophobic tails of the receptor, whereas hydrophilic groups of the receptor were directed towards the electrolyte solution enhancing the ion transport through the lipid membranes. The magnitude of the transient current signal was related to the concentration of the stimulating agent in bulk solution in the micromolar range. No interferences from ascorbic acid were noticed because of the use of the negatively charged lipids in membranes. The present technique can be used as one-shot sensor for the detection of these pharmaceutical substances and future research is targeted to the determination of these chemicals in human biofluids such as urine of athletes.

A minisensor for the rapid screening of sucralose based on surface-stabilized bilayer lipid membranes

This work describes an electrochemical technique that is suitable for the rapid and sensitive screening of the sweetener sucralose based on surface-stabilized bilayer lipid membranes (s-BLMs) composed of egg phosphatidylcholine. The interactions of sucralose with s-BLMs produced electrochemical ion current increases, which appeared reproducible within a few seconds after exposure of the membranes to the sweetener. The mechanism of signal generation was investigated by differential scanning calorimetric studies. The mechanism was found to be associated with alteration of the electrostatic fields of the lipid film. These studies revealed that an increase of the molecular area of the lipids at the membranes and a stabilization of a gel phase structure occurred due to adsorption of the sweetener. Water molecules are adsorbed at the polar headgroups of the lipids, which changes the electrostatic field at the surface of the membranes. The current signal increases were related to the concentration of sucralose in bulk solution in the micromolar range. The present lipid film based sensor provided a fast response (i.e. in the order of a few seconds) to alterations of sucralose concentration (5-50 microm) in electrolyte solution. The electrochemical transduction of the interactions of this artificial sweetener with s-BLMs was applied in the determination of this compound in granulated sugar substitute products using the present minisensor.