Sensitive tear screening of diabetic retinopathy with dual biomarkers enabled using a rapid electrokinetic patterning platform

A screening technique with dual biomarkers for diabetic retinopathy (DR) based on optoelectrokinetics was presented. Our technique will revolutionize the diagnostic method for DR and enable an early treatment to improve patients' quality of life.

Development of a Bead-Based Optoelectrokinetic Immunosensing Technique for Detection of Low-Abundance Analytes

Bead-based immunosensing has been growing as a promising technology in the point-of-care diagnostics because of great flexibility. For dilute samples, functionalized particles can be used to collect dispersed analytes and act as carriers for particle manipulation. To carry out rapid and selective diagnosis, a bead-based optoelectrokinetic immunosensing technique was developed herein to detect biomarkers, lipocalin 1 (LCN1) and TNF-α, for diabetic retinopathy (DR). The measurement was made in a sample droplet sandwiched between two parallel electrodes. With an electric field and a focused laser beam simultaneously applying on the microchip, the immunocomplexes in the droplet were further concentrated within the region of irradiation to enhance the fluorescent signal. The optoelectrokinetic platform, termed rapid electrokinetic patterning (REP), is excellent in dynamic and programmable particle manipulation. Therefore, the detection could be complete in roughly 10 s. With an appropriate frequency modulation, the two DR biomarkers were detected at a time. The limit of detection (LOD) of the REP-enabled measurement reached as low as 100 pg/mL. The combined use of bead-based immunoassays and the optoelectrokinetic platform therefore provides an insightful measure to the early diagnosis of diseases.

An optoelectrokinetic technique for programmable particle manipulation and bead-based biosignal enhancement

An optoelectrokinetic technique, termed Rapid Electrokinetic Patterning (REP), was used to enhance the signal in bead-based bioassays. REP can achieve various manipulation capabilities.

Towards New Methodologies for Manipulation of Colloidal Particles in a Miniaturized Fluidic Device: Optoelectrokinetic Manipulation Technique

The rapid electrokinetic patterning (REP) technique developed recently is a hybrid optoelectrokinetic one that manipulates micro- or nanocolloids in a microfluidic chip using the simultaneous application of a uniform ac electric field and laser illumination. Since its invention, the technique has been applied to many research fields with promising potential, but these applications are still in their early stages. In order to effectively complete and leverage the applications, this paper reviews the publications concerning the REP technique and discusses its underlying principles, applications, and future prospects.

Electrothermal Pumping With Thin Film Resistive Heaters

Rapid Electrokinetic Patterning (REP) is a technique used to gather suspended colloidal particles at a planar electrode surface. REP is capable of gathering colloids using very simplistic electrode geometry. Two parallel plate electrodes are used to supply an AC electric field, and an infrared laser is required to heat the surface. Gold and indium tin oxide (ITO) on glass slides have been used as electrode material. Experiments were conducted using ITO coated glass slides, a 980 nm infrared laser, one-micron red fluorescent polystyrene particles, and an aqueous KCl solution. An inverted Nikon Eclipse microscope was used, and video was captured using a PCO Sensicam camera.

Optically Induced Electrokinetic Trapping and Sorting of Colloids

Recently, we have demonstrated electrothermal hydrodynamics with an external heating source of a highly focused 1,064 nm laser beam [1]. This phenomenon, when coupled with particle-electrode electrokinetic interactions, has led to the rapid and selective concentration of suspended colloids [2–6]. This technique, termed Rapid Electrokinetic Patterning (REP) was demonstrated without any additional surface modification or patterning of the electrodes. This dynamic, optically induced fluid and particle manipulation technique could be used for a variety of lab-on-a-chip applications. However, there are additional effects that have yet to be investigated that are important for a complete understanding of REP. This paper showcases experimental particle-particle behavior observations by varying particle diameter, electrode material, and preliminary results of varying fluid electrical conductivity.