Enhancing affinity‐based electroanalytical biosensors by integrated AC electrokinetic enrichment—A mini review

Abstract

Biosensors play a central role in moving diagnostics to being on‐site or decentralized. Affinity biosensor, an important category of biosensors, has important applications in clinical diagnosis, pharmaceuticals, immunology, and other fields. Affinity biosensors rely on specific binding between target analytes and biological ligands such as antibodies, nucleic acids, or other receptors to generate measurable signals. Oftentimes the target analytes in practical samples are of low abundance in a complex matrix. Traditional affinity biosensors mainly rely on random diffusion of analytes in solution to conjugate with biorecognition elements on the sensor surface of electrodes. The process may take hours or even days, which is not conducive to rapid and sensitive detection of biosensors. Therefore, it is strongly desired to incorporate an enrichment mechanism for target analytes into biosensor‐based detection. AC electrokinetic (ACEK) effect can realize rapid enrichment of analytes by application of AC electric fields, which holds great promise for achieving high sensitivity, low detection limit, and rapid turnaround. This article reviews the studies of affinity biosensors integrated with ACEK enrichment in the past decade, and summarizes the latest detection methods, detection devices and applications, hoping to provide some insights and references for researchers in related fields.

Surface plasmon resonance aptasensor for soluble ICAM-1 protein in blood samples

“…Enrichment of samples was employed when the sensing platform was directly affected by the sample ingredients. 8,9 Magnetic enrichment can depend on specific or non-specific methods of target analysts. [10][11][12] Most of the biosensors were based on the immunoaffinitybased platforms, such as optical, electrochemical or ELISA.…”

“…Enrichment of samples was employed when the sensing platform was directly affected by the sample ingredients. 8,9 Magnetic enrichment can depend on specific or non-specific methods of target analysts. 10–12…”

Dielectrophoresis: An Approach to Increase Sensitivity, Reduce Response Time and to Suppress Nonspecific Binding in Biosensors?

“…Therefore, the use of pumps and electric fields for reasons of mixing rather than simple locomotion would be classified as an active mixing system [ 25 ]. AC electrokinetic and its implications in biosensors is a growing field of research with proof of principle experiments that has shown a decrease of the limit of detection by several orders of magnitude and decreased the detection time from hours to minutes [ 26 , 27 ]. The most frequently applied methods to increase the mass transfer and achieve an enrichment of analytes on the sensor surface are AC electroosmosis, AC electrothermal effect [ 28 , 29 ] and dielectrophoresis (DEP).…”

“…While previous reviews have covered generally AC electrokinetic enhanced biosensors [ 26 , 27 ], DEP in microbial sensors [ 34 ] or the detection of biomarkers [ 35 ], we are here aiming to cover biosensors assisted with DEP in the light of new theoretical approaches, recent examples and critically discuss their potential to increase sensitivity and to decrease the assay time of biosensors. Key aspects in this endeavor are an improved mass transfer and the avoidance of nonspecific bindings.…”

Facile and Sensitive Method for Detecting Bisphenol A UsingUbiquitous pH Meters

“…These methods are expensive and time‐consuming, which restricts their practical applications. A better understanding of BPA exposure levels requires field‐deployable instruments that can be used to monitor BPA levels on‐site in living environments [10] . A sensitive and simple method using easy‐to‐operate readout equipment is needed to detect BPA practically.…”