New approach to selective detection of 2,4-dichlorophenoxyacetic acid with a cholinesterase amperometric biosensor

A new method of detection of 2,4-dichlorophenoxyacetic acid by means of immobilized monoclonal antibodies and an amperometric cholinesterase biosensor is proposed. A combination of monoclonal antibodies to 2,4-dichlorophenoxyacetic acid with an enzyme electrode provides high selectivity of measurements and allows trace amounts of this pesticide to be detected within a concentration range of 1 × 10-1 to 5 × 10-7 M with a sensitivity threshold of 5 × 10-12 M

Metal ions as effectors of enzymes

Effects of metal ions as modulators of enzymes are considered. Data on inhibition and activation by metal ions are reviewed. Dual action of modulators depending on enzyme nature and effector concentration are noted. Analytical application of metal ions effects is discussed

Analytical possibilities of amperometric choline esterase biosensors in continuous-flow analysis

A model set-up of a simple and convenient continuous-flow analyzer (enzyme reactor) that includes an amperometric choline esterase biosensor for the determination of potential contaminants of the environment is developed. Various modifications of the biosensors developed are used for determination of toxicants in a flow within the concentration range from 1 × 10-3 to n × 10-13 M over 16-36 h. ©1996 Plenum Publishing Corporation

Metal ions as enzyme effectors

The role of metal ions as enzyme effectors is considered. Data on inhibitory and activating effects of metal ions are summarised. The dual character of action of the effectors depending on their concentration and the nature of the enzyme is highlighted. The analytical applications of these effects are discussed. © 1998 Russian Academy of Sciences and Turpion Ltd

An enzyme amperometric sensor for toxicant determination

An enzyme sensor with amperometric recording of the analytic signal for determination of a number of cholinesterase (ChE) inhibitors (P-, Cl-containing pesticides, heavy metals) has been developed. It consists of a mercury film-covered silver electrode and ChE immobilized in the nitrocellulose film in the presence of glutaraldehyde. It is shown that the enzyme electrode can be used as a component of an enzyme reactor for the determination of ChE inhibitors and activators under flow conditions. © 1991

Examining the challenges of the Russian sharing economy: the institutional and evolutionary approach

This study examines the key features of Russian sharing economy business specialized in food delivery using the institutional and evolutionary approach. Existing business models used by Russian food delivery companies are characterized by a high level of information asymmetry in the employee-employer relationship. This has led to a great deal of tension and resulted in the open conflict between food delivery companies and couriers. This study is a qualitative research initiative based on a series of semi-structured in-depth interviews with the employees of delivery companies. The results obtained enabled us to distinguish between two groups of couriers. While most “part-time” couriers, who work no longer than 4 hours per shift, are satisfied with their labor conditions, there is a widespread opinion among “full-time” delivery workers that they are underpaid and overloaded. Popular institutionalized form of employment that Russian food delivery companies offer for couriers is self-employment. This form of employment has low social guarantees however minimize employers’ expenses on personnel and social contributions. Even though digital platforms position themselves as reliable partners providing employees with the opportunities for flexible working hours and decent pay, in reality couriers become a very vulnerable and precariatized social group without proper social guarantees and future prospects

A new approach to selective detection of 2,4-dichlorophenoxyacetic acid with a cholinesterase amperometric biosensor

A new method of detection of 2,4-dichlorophenoxyacetic acid by means of immobilized monoclonal antibodies and an amperometric cholinesterase biosensor is proposed. A combination of monoclonal antibodies to 2,4-dichlorophenoxyacetic acid with an enzyme electrode provides high selectivity of measurements and allows trace amounts of this pesticide to be detected within a concentration range of 1 × 10-11 to 5 × 10-7 M with a sensitivity threshold of 5 × 10-12 M

Amperometric sensors based on immobilised enzymes

The state, problems, and prospects of the development of one of the new fields of analytical chemistry — "Reagent-free" analytical methods — are described and surveyed using as an example enzyme-based amperometric sensors. Questions associated with the design of biosensors and the characteristics of their functioning under various conditions are examined. The applied aspects of the use of enzyme electrodes of this type in various fields of science and the national economy are noted. The bibliography includes. © 1991 IOP Publishing Ltd

A New Amperometric Biosensor Based on Platinum(II) Complex with DNA for Detecting Autoantibodies to DNA

A biochemical biosensor was developed on the basis of a steady-state Hg-film electrode and either DNA molecules or antibodies to DNA immobilized in a cellulose nitrate film. This biosensor is designed to measure the concentration of DNA (or antibodies to DNA), and it can be used in the diagnosis of autoimmune diseases. Electric current of catalytic H2 evolution caused by complexing between DNA (antibodies to DNA) and Pt(II) was used as an analytical signal. The detection sensitivity threshold for DNA and antibodies to DNA was 10 and 0.075 μg/ml, respectively

A new amperometric biosensor based on platinum(II) complex with DNA for detecting autoantibodies to DNA

A biochemical biosensor was developed on the basis of a steady-state Hg-film electrode and either DNA molecules or antibodies to DNA immobilized in a cellulose nitrate film. This biosensor is designed to measure the concentration of DNA (or antibodies to DNA), and it can be used in the diagnosis of autoimmune diseases. Electric current of catalytic H2 evolution caused by complexing between DNA (antibodies to DNA) and Pt (II) was used as an analytical signal. The detection sensitivity threshold for DNA and antibodies to DNA was 10 and 0.075 μg/ml, respectively