Electrokinetic Active Particles for Motion-Based Biomolecule Detection

Abstract

Detection of biomolecules is essential for patient diagnosis, disease management, and numerous other applications. Recently, nano- and microparticle-based detection has been explored for improving traditional assays by reducing required sample volumes and assay times as well as enhancing tunability. Among these approaches, active particle-based assays that couple particle motion to biomolecule concentration expand assay accessibility through simplified signal outputs. However, most of these approaches require secondary labeling, which complicates workflows and introduces additional points of error. Here, we show a proof-of-concept for a label-free, motion-based biomolecule detection system using electrokinetic active particles. We prepare induced-charge electrophoretic microsensors (ICEMs) for the capture of two model biomolecules, streptavidin and ovalbumin, and show that the specific capture of the biomolecules leads to direct signal transduction through ICEM speed suppression at concentrations as low as 0.1 nM. This work lays the foundation for a new paradigm of rapid, simple, and label-free biomolecule detection using active particles.

Microrobots for Biomedicine: Unsolved Challenges and Opportunities for Translation

“…The revolutionary capabilities of microrobots have sparked a flurry of scientific research aimed at pushing the boundaries of biomedical research. Advancements in propulsion science, materials engineering, and fluid mechanics has enabled engineers and scientists to create microrobots with a suite of functionalities. − Such functions include transporting living cells and other biological cargo, moving through complex heterogeneous biological media, providing targeted and controlled drug delivery, , offering switchable control over modes of locomotion, , and enabling in vivo imaging . These advancements have fueled proof-of-concept studies in areas such as ocular drug delivery, in vitro fertilization, root canal prevention, and tumor treatment, among others.…”

Nanomotor-enhanced transport of passive Brownian particles in porous media

“…Self-propulsion and active matter have emerged as intriguing fields of basic research. Beyond biological examples such as bacteria and molecular motors, artificial micro-and nanomotors have drawn extensive attention due to the fundamental interest in their emergent collective behaviors and broad potential applications [e.g., environmental remediation (1) and drug delivery (2,3)]. The study of active particles in bulk and pseudo-two-dimensional (2D) environments is well established (4)(5)(6)(7)(8)(9), and there is growing interest in their behavior in 3D complex interface-rich and species-rich environments, where unexpected phenomena have been observed (10)(11)(12).…”

Magnetically locked Janus particle clusters with orientation-dependent motion in AC electric fields

“…Micromotors composed of active colloidal particles have found use in a multitude of applications, including drug delivery, 1–4 cell manipulation, 5–7 flexible electronics, 8–10 and cargo transport. 11–15 Such micromotors can be propelled by various energy sources, including magnetic, 16–21 acoustic, 2,22–24 and electric fields, 11,25–28 as well as catalytic reactions. 29–33 As a category of electrical stimulation, induced-charge electrophoresis (ICEP) is a useful method to drive the motion of metallodielectric particles ( e.g.…”