This article describes a brief history of chemical warfare, which culminated in the signing of the Chemical Weapons Convention. It describes the current level of chemical weapons and the risk of using them. Furthermore, some traditional technology for the development of chemical weapons, such as increasing toxicity, methods of overcoming chemical protection, research on natural toxins or the introduction of binary technology, has been described. In accordance with many parameters, chemical weapons based on traditional technologies have achieved the limit of their development. There is, however, a big potential of their further development based on the most recent knowledge of modern scientific and technical disciplines, particularly at the boundary of chemistry and biology. The risk is even higher due to the fact that already, today, there is a general acceptance of the development of non-lethal chemical weapons at a technologically higher level. In the future, the chemical arsenal will be based on the accumulation of important information from the fields of chemical, biological and toxin weapons. Data banks obtained in this way will be hardly accessible and the risk of their materialization will persist.

Toxin weapon research, development, production and the ban on its uses is an integral part of international law, with particular attention paid to the protection against these weapons. In spite of this, hazards associated with toxins cannot be completely excluded. Some of these hazards are also pointed out in the present review. The article deals with the characteristics and properties of natural toxins and synthetic analogs potentially constituting the basis of toxin weapons. It briefly describes the history of military research and the use of toxins from distant history up to the present age. With respect to effective disarmament conventions, it mentions certain contemporary concepts of possible toxin applications for military purposes and the protection of public order (suppression of riots); it also briefly refers to the question of terrorism. In addition, it deals with certain traditional as well as modern technologies of the research, synthesis, and use of toxins, which can affect the continuing development of toxin weapons. These are, for example, cases of new toxins from natural sources, their chemical synthesis, production of synthetic analogs, the possibility of using methods of genetic engineering and modern biotechnologies or the possible applications of nanotechnology and certain pharmaceutical methods for the effective transfer of toxins into the organism. The authors evaluate the military importance of toxins based on their comparison with traditional chemical warfare agents. They appeal to the ethics of the scientific work as a principal condition for the prevention of toxin abuse in wars, military conflicts, as well as in non-military attacks.

Cholinesterase inhibitors are widely used as pesticides in agriculture, but also form a group of organophosphates known as nerve chemical warfare agents. This calls for close attention regarding their detection, including the use of various biosensors. One such biosensor made in the Czech Republic is the Detehit, which is based on a cholinesterase reaction that is assessed using a colour indicator—the Ellman’s reagent—which is anchored on cellulose filter paper together with the substrate. With the use of this biosensor, detection is simple, quick, and sensitive. However, its disadvantage is that a less pronounced yellow discoloration occurs, especially under difficult light conditions. As a possible solution, a new indicator/substrate carrier has been designed. It is made of glass nanofibres, so the physical characteristics of the carrier positively influence reaction conditions, and as a result improve the colour response of the biosensor. The authors present and discuss some of the results of the study of this carrier under various experimental conditions. These findings have been used for the development of a modified Detehit biosensor.

Colorimetric biosensors of cholinesterase inhibitors are ideal for fast, reliable, and very simple detection of agents in air, in water, and on surfaces. This paper describes an innovation of the Czech Detehit biosensor, which is based on a biochemical enzymatic reaction visualized by using Ellman’s reagent as a chromogenic indicator. The modification basically consists of a much more distinct color response of the biosensor, attained through optimization of the reaction system by using Guinea Green B as the indicator. The performance of the modified biosensor was verified on the chemical warfare agents (sarin, soman, cyclosarin, and VX) in water. The detection limits ascertained visually (with the naked eye) were about 0.001 µg/mL in water (exposure time 60 s, inhibition efficiency 25%).

This work provides a summary of our results in the area of the experimental development of detection paper for the detection of liquid phase chemical warfare agents (drops, aerosol), the presence of which is demonstrated by the development of characteristic coloring visible to the naked eye. The basis of the detection paper is a cellulose carrier saturated with the dithienobenzotropone monomer (RM1a)–chromogenic chemosensor sensitive to nerve agents of the G type, blister agent lewisite, or choking agent diphosgene. We achieve a higher coloring brilliance and the limit certain interferences by using this chemosensor in the mix of the o-phenylendiamine-pyronine (PY-OPD). We prove that the addition of the Bromocresol Green pH indicator even enables detection of nerve agents of the V type, or, nitrogen mustards, while keeping a high stability of the detection paper and its functions for other chemical warfare agents. We resolve the resistance against the undesirable influence of water by providing a hydrophobic treatment of the carrier surface.

The extreme toxicity of nerve agents and the broad spectrum of their physical and chemical properties, enabling the use of these agents in a variety of tactical situations, is a continuing challenge in maintaining the knowledge and capability to detect them, as well as in finding new effective methods. Despite significant advances in the instrumentation of the analysis of nerve agents, relatively simple methods based on the evaluation of colour signals (absorption and fluorescence), in particular those using the cholinesterase reaction, continue to be of importance. This review provides a brief presentation of the current status of these simple methods, with an emphasis on military applications, and illustrates the high interest of the professional community in their further development. At the same time, it also contains some peculiarities (high reliability and durability, resistance to extreme climatic conditions, work in deployed means of protection, low purchase prices, economic availability especially in a state of war, etc.) that the authors believe research and development of simple methods and means for the detection of nerve agents should respect.