Biosensors

Abstract

The sections in this article are Introduction Basic Principles and Setup Application of Biosensors. Principal Considerations Biorecognition Elements Catalytic Biorecognition Elements Bioaffinity Recognition Elements Transducers and Instrumentation Amperometric Electrodes Potentiometric Sensors Conductometric and Impedimetric Transducers Coupling of Biorecognition Elements and Transducers Specific Features of Electrochemical Biosensors Amperometric Biosensors Shuttle Mechanism Using Free‐diffusing Natural Redox Mediators Artificial Redox Compounds as Free‐diffusing Electron‐Transfer Mediators Immobilized Redox Mediators—“Electroenzymes” “Wired” Enzymes by Means of Redox Hydrogels Conducting Polymers Direct Electron Transfer between Redox Enzymes and Electrodes Potentiometric Biosensors Potentiometric Enzyme Biosensors Potentiometric Immunosensors Field‐effect Transistors Conductometric and Impedimetric Biosensors Miniaturization and Future Aspects Miniaturized Transducers Advantages and Problems of Miniaturized Biosensors Multisensor Arrays and Sensor Chips

In-Situ AFM Studies of the Phase-Transition Behavior of Single Thermoresponsive Hydrogel Particles

“…These polymers are characterized by a highly complex phase transition behavior, which in addition is dependent on the ionic strength of the solution and the size of the ions . The responsive properties render such hydrogels suitable as matrixes for a variety of applications ranging from drug delivery 2,3 to biosensor design ,− Furthermore, most hydrogels are biocompatible with interfaces resistant to biofouling. , To explore these applications, fundamental knowledge on the VPT behavior, ideally at individual immobilized particles, is a prerequisite.…”

Distributed Environmental Monitoring

“…855 Enzymes constitute one of the most attractive approaches to transduction, as they 856 facilitate amplification of the signal, due to the biological catalytic reaction, and 857 display excellent selectivity, due to the high specificity towards a particular sub-858 strate [120,123,193]. As enzymes accelerate the equilibrium formation of a 859 chemical reaction, sensors based on enzymes are intrinsically reversible and may 860 be regenerated [123,193], which is beneficial for lowering the cost basis.…”

“…As enzymes accelerate the equilibrium formation of a 859 chemical reaction, sensors based on enzymes are intrinsically reversible and may 860 be regenerated [123,193], which is beneficial for lowering the cost basis. Screen 861 printing and inkjet formulations for the preparation of disposable enzyme-based 862 sensors have been explored [131].…”

“…Screen 861 printing and inkjet formulations for the preparation of disposable enzyme-based 862 sensors have been explored [131]. The principal type of detection for these sensors 863 is amperometric and while potentiometric [174] and conductometric [193] 864 approaches have also been used, these tend to be more dependent on the ionic 865 strength and pH of the sample solution [123], i.e., less suitable for autonomous 866 remote monitoring. However, in sensors wherein the products of enzymatic reac-867 tion are gaseous, conductometric detection can be very successful when coupled 868 with a gas-permeable membrane to remove most interferences [123].…”

“…Entrapment of enzymes in gel formulations and/or water-based carbon ink, compati-880 ble with screen printing and capable of improving the enzymatic stability, yet holds 881 great promise for the preparation of enzyme biosensors [123,130,193] …”