Electrochemical immunoassay applications

Ho, W. O., Athey, D., and McNeil, C. J. Amperometric detection of alkaline phosphatase activity at a horseradish peroxidase enzyme electrode based on activated carbon - Potential application to electrochemical immunoassay. Biosens. Bioelectron. 1995,10, 683-691. 

Furthermore, the DET to another blue oxidase ascorbate oxidase has been studied [64]. The IP of the Tl-site is close to the value of Rhus vernificera laccase and oxygen was catalytically reduced. Analytical application can be found in the electrochemical immunoassays described below. 

Creatinine. Electrophoresis Principles Isoelectric Focusing. Enzymes Enzymes In Physiological Samples Industrial Products and Processes Enzyme Assays. Forensic Sciences Alcohol In Body Fluids DNA Profiling Systematic Drug Identification Thin-Layer Chromatography. Immunoassays Applications Forensic. Microscopy Applications Forensic. Nucleic Acids Electrochemical Methods. Polymerase Chain Reaction. Spectrophotometry Oven/lew Biochemical Applications. 

See also. Chemiluminescence Oven/iew. Derivatiza-tion of Analytes. Electrophoresis Oven/iew. Enzymes Oven/iew Immobiiized Enzymes Enzyme-Based Eiec-trodes Enzymes in Physioiogicai Sampies Industriai Products and Processes Enzyme-Based Assays. Fluorescence Clinical and Drug Applications. Immunoassays Overview Production of Antibodies. Immunoassays, Applications Clinical Food Forensic. Immunoassays, Techniques Radioimmunoassays Enzyme Immunoassays Luminescence Immunoassays. Mass Spectrometry Polymerase Chain Reaction Products. Nucleic Acids Chromatographic and Electrophoretic Methods Electrochemical Methods. Polymerase Chain Reaction. 

Volume 3 of this series may be consulted for a survey of electrochemical instrumentation and electroanalytical chemistry. In addition, several chapters in this volume contain detailed information on methods of importance to bioanalysis. In particular. Chapter 17 (mediated electron transfer). Chapter 7 (electrochemistry of nitric oxide). Chapter 12 (electrochemistry of nucleic acids). Chapter 13 (enzyme electrodes). Chapter 14 (in vivo electrochemistry), Chapter 5 (electrochemical immunoassays), Chapter 2 (single cell electrochemistry), and Chapter 9 (ion-selective electrodes) provide more details on the fundamental processes underlying the applications to bioanalysis that are described in this chapter. 

Although this section has discussed immunoassay methods with potential for the development of sensors based on fibre optics, electrochemical immunoassay methods (10) may also find application in sensors development. Of particular interest is the use of piezoelectric crystals in immunoassay (11). 

Electrochemical immunoassays may offer some advantages over other multiplex sensing technologies, which often require expensive reagents and complex instrumentation. As described in the following sections, the application of nanomaterials to electrochemical immunoassays and other types of electrochemical biosensing devices has resulted in extremely sensitive analytical techniques for multiplexed analyses. 

One of the most exciting new applications for electrochemistry in the last decade has been in the area of immunoassay. With more than a hundred million immunoassays being performed world-wide each year, researchers have begun to carve out new immunoassay strategies which exploit the excellent detection limits that can be achieved with modem electrochemical techniques. 

The specific electrochemical behaviour of IDAs is result of its design [97], i.e. two arrays intercalated and individually addressed in a bipotentiostatic system where reversible redox species can be cycled between one array (generator) and the other array (collector) (Fig. 32.3). The feedback obtained, greatly enhances the current and high sensitive detection can be achieved. An important application of IDAs is the electrochemical detection of p-aminophenol when it is generated from p-aminophenyl phosphate, by enzymatic reaction with alkaline phosphatase (like enzymatic label), in geno- [98-100] and immunoassays [101-103]. Another interesting feature of IDAs is the possibility of... 

The use of ELISA is broad and it finds applications in many biological laboratories over the last 30 years many tests have been developed and vahdated in different domains such as clinical diagnostics, pharmaceutical research, industrial control or food and feed analytics for instance. Our work has been to redesign the standard ELISA test to fit in a microfluidic system with disposable electrochemical chips. Many applications are foreseen since the biochemical reagents are directly amenable from a conventional microtitre plate to our microfluidic system. For instance, in the last 5 years, we have reported previous works with this concept of microchannel ELISA for the detection of thromboembolic event marker (D-Dimer) [4], hormones (TSH) [18], or vitamin (folic acid) [24], It is expected that similar technical developments in the future may broaden the use of electroanalytical chemistry in the field of clinical tests as has been the case for glucose monitoring. This work also contributes to the novel analytical trend to reduce the volume and time consumption in analytical labs using lab-on-a-chip devices. Not only can an electrophoretic-driven system benefit from the miniaturisation but also affinity assays and in particularly immunoassays with electrochemical detection. 

The properties of high specificity and a wide applicability with many analytes have led to the widespread use of immunoanalytical techniques. The benefits of electrochemical sensors include technical simplicity, speed, and convenience via direct transduction to electronic equipment. Combining these two systems offers the possibility of a convenient assay technique with high selectivity. Because of the complexity of immunoassay methods, such devices have not yet found widespread use. Nevertheless, electrochemical immuno-sensors offer the potential for fast, simple, cost-effective analysis of many... 

---