Investigating the effect of design parameters on the response time of a highly sensitive microbial hydrogen sulfide biosensor based on oxygen consumption

Biopolymer Composites with Sensors for Environmental and Medical Applications

One of the biggest economic and environmental sustainability problems is the over-reliance on petroleum chemicals in polymer production. This paper presents an overview of the current state of knowledge on biopolymers combined with biosensors in terms of properties, compounding methods and applications, with a focus on medical and environmental aspects. Therefore, this article is devoted to environmentally friendly polymer materials. The paper presents an overview of the current state of knowledge on biopolymers combined with biosensors in terms of properties, compounding methods and applications, with a special focus on medical and environmental aspects. The paper presents the current state of knowledge, as well as prospects. The article shows that biopolymers made from renewable raw materials are of great interest in various fields of science and industry. These materials not only replace existing polymers in many applications, but also provide new combinations of properties for new applications. Composite materials based on biopolymers are considered superior to traditional non-biodegradable materials due to their ability to degrade when exposed to environmental factors. The paper highlights the combination of polymers with nanomaterials which allows the preparation of chemical sensors, thus enabling their use in environmental or medical applications due to their biocompatibility and sensitivity. This review focuses on analyzing the state of research in the field of biopolymer-sensor composites.

Cell-based biosensors: Recent trends, challenges and future perspectives

Existing at the interface of biology and electronics, living cells have been in use as biorecognition elements (bioreceptors) in biosensors since the early 1970s. They are an interesting choice of bioreceptors as they allow flexibility in determining the sensing strategy, are cheaper than purified enzymes and antibodies and make the fabrication relatively simple and cost-effective. And with advances in the field of synthetic biology, microfluidics and lithography, many exciting developments have been made in the design of cell-based biosensors in the last about five years. 3D cell culture systems integrated with electrodes are now providing new insights into disease pathogenesis and physiology, while cardiomyocyte-integrated microelectrode array (MEA) technology is set to be standardized for the assessment of drug-induced cardiac toxicity. From cell microarrays for high-throughput applications to plasmonic devices for anti-microbial susceptibility testing and advent of microbial fuel cell biosensors, cell-based biosensors have evolved from being mere tools for detection of specific analytes to multi-parametric devices for real time monitoring and assessment. However, despite these advancements, challenges such as regeneration and storage life, heterogeneity in cell populations, high interference and high costs due to accessory instrumentation need to be addressed before the full potential of cell-based biosensors can be realized at a larger scale. This review summarizes results of the studies that have been conducted in the last five years toward the fabrication of cell-based biosensors for different applications with a comprehensive discussion on the challenges, future trends, and potential inputs needed for improving them.

Novel microfluidic graphene oxide-protein amperometric biosensor for detecting sulfur compounds

Sulfur compounds are essential for many industries and organisms; however, they cause serious respiratory problems in human beings. Therefore, determination of sulfur concentration is of paramount importance. The research approach in the field of detecting contaminants has led to smaller systems that provide faster and more effective ways for diagnosis purposes. In this study, a novel portable amperometric graphene oxide-protein biosensor platform is investigated. The main characteristic of this structure is the implementation of a microfluidic configuration. With albumin metalloprotein as the biorecognition element, graphene oxide was synthesized and characterized by transmission electron microscopy and Fourier-transform infrared spectroscopy (FTIR). Albumin protein was stabilized on the surface of graphene oxide by the application of the N-(3-dimethylamionpropyl)-N-ethylcarbodiimide hydrochloride/N-hydroxysuccinimide method. The stabilization was confirmed by FTIR and electrochemistry analyses. The calibration curve of sulfur concentration was determined. When the graphene oxide-protein complex was stabilized by nephion on the surface of the microfluidic system, the response time reduced to 50 Sec, which is a relatively faster response among the similar studies and validated the significant effect of the microfluidic system. The nanosystem had an optimized pH of 7.4 and exhibited high sensitivity in determining sulfide. The results confirm that the portable graphene oxide-protein nanosystem has a fast and accurate response in detecting sulfide.

Current status of water environment and their microbial biosensor techniques - Part II: Recent trends in microbial biosensor development

In Part I of the present review series, I presented the current state of the water environment by focusing on Japanese cases and discussed the need to further develop microbial biosensor technologies for the actual water environment. I comprehensively present trends after approximately 2010 in microbial biosensor development for the water environment. In the first section, after briefly summarizing historical studies, recent studies on microbial biosensor principles are introduced. In the second section, recent application studies for the water environment are also introduced. Finally, I conclude the present review series by describing the need to further develop microbial biosensor technologies. Graphical abstract Current water pollution indirectly occurs by anthropogenic eutrophication (Part I). Recent trends in microbial biosensor development for water environment are described in part II of the present review series.

Selective recognition of hydrogen sulfide using template and catalyst free grown ZnO nanorods

A single step spray pyrolysis technique was used to grow ZnO nanorods on glass substrates without any template or catalyst and the nanorods were successfully employed to detect hydrogen sulfide at room temperature.