Recent advances in AC electrokinetic sample enrichment techniques for biosensor development

Integration of biosensing techniques with microfluidics has enabled less sample consumption and increased sensitivity. In addition, it offers a potential improvement with respect to slow diffusion-limited sensing, as well as the incorporation of several sample handling parts into a single lab-on-a-chip device. One highly efficient technique in microfluidics that can be utilized in pre-sensing sample preparation steps such as sorting, separation, trapping, enrichment, and labelling is electrokinetics. AC electroosmosis, AC electrothermal, and dielectrophoresis are among the highly applicable electrokinetic methods used for pre-sensing sample preparation for enhancing sensitivity, limit-of-detection, and selectivity of biosensing devices. In this review article, we focus on these three electrokinetic techniques used for sample enrichment in the field of biosensing technology. First, the working principals of electrothermal, electroosmosis, and dielectrophoresis are characterized, and then their recent advances and major achievements in sample enrichment for biosensors are discussed