Advances in electrochemical immunosensors

Abstract

The developments in the field of electrochemical immunosensors and immunoassays are reviewed. The enzyme labels suitable for amperometric, potentiometric and conductimetric detection are mentioned. Indirect immunosensors (i.e., that involving enzymatic or electroactive labels) use either heterogeneous or homogeneous formats. Immunoelectrodes are based on conventional electrodes, semiconductor devices are represented by ISFETs and light addressable potentiometric sensors (LAPS). Direct label-free monitoring of immunoreactions is demonstrated on capacitance systems and pulsed detection using polypyrrole-modified electrodes. The approaches to regeneration of sensing surfaces are discussed. Examples are given on applications of electrochemical immunodevices in clinical medicine and in environmental monitoring.

Label‐Free Impedance Biosensors: Opportunities and Challenges

“…Besides the time and expense benefits of omitting the labeling step, label-free operation enables detection of target-probe binding in real time [45], which is generally not possible with labelbased systems. Real-time sensing confers at least two major advantages over endpoint detection.…”

Electrochemical sensors: a powerful tool in analytical chemistry

“…Recently, mimetic molecules have also been suggested, instead of enzymes or antibodies. 127,128 The interaction between the antibody (A b ) and antigen (A g ) is characterised by its affinity constant, K, defined by the equilibrium concentrations of the A b -A g complex, the free analyte and the free antibody binding sites (where…”

Biosensors for Biological Warfare Agent Detection

“…Light-addressable potentiometric sensors (LAPS) biosensors are capable of signal amplification due to the incorporated field effect transistor (FET). Light-addressable potentiometric sensors (LAPS) are heterostructures consisting of a silicon base covered with silicon oxide and silicon nitride layers 10 . The backward illumination with light emitting diode (LED) induces a change of conductivity in the sensing area, and after formation of the immunocomplex labeled with urease, the change of pH is registered.…”