Single-DNA-molecule trapping with silicon nanotweezers using pulsed dielectrophoresis

Abstract

DNA manipulation based on dielectrophoresis between microfabricated electrodes is one of the most efficient methods for the physical handling of molecules. Dielectrophoresis is routinely used for stretching and trapping DNA molecules between the opposing tips of silicon nanotweezers. However, the precise number of trapped molecules is difficult to predict, as a continuous application of ac voltage continually attracts the molecules while the electric-field-induced fluid flow prevents them from bridging the tips. To circumvent this difficulty, the dielectrophoresis signal is applied during very short intervals. In this pulsed mode, the electrohydrodynamic fluid flow is lessened and the molecule trapping success rate is greatly enhanced. A fluorescently labeled single λ-DNA molecule was successfully stretched and captured by the silicon nanotweezers with 50 ms pulses of a 1 MHz, 1 MV m−1 ac dielectrophoresis voltage. This single-molecule trapping between the tweezers' tips is monitored, in real time, under fluorescence imaging.

DNA dielectrophoresis: Theory and applications a review

“…This approach provided the capability to manipulate a single molecule, for example, to move DNA molecules to a specific position in a microbioelectronic device. These achievements pave the way for fabrication of a new class of molecular biosensor based on silicon microtechnology .…”

“…With that experimental realization the electric properties of a single DNA molecule could be determined in contrast to [63] where several DNA molecules were trapped at the same time. In their later work [107], Kumemura et al successfully captured a single-DNA molecule between the tips of silicon nanotweezers by DEP. This approach provided the capability to manipulate a single molecule, for example, to move DNA molecules to a specific position in a microbioelectronic device.…”

Rapid and selective concentration of bacteria, viruses, and proteins using alternating current signal superimposition on two coplanar electrodes

“…latex particles DI water (0.25 μS/cm) DEP: 1.6 Vpp, 5 kHz, EO: 1.6 Vpp, 300 Hz, 5 min Square spiral (5–30 μm/5 μm) Cr/Au 25 Signal Superposition for DEP DEP + twDEP (sine + sine superposition) T lymphocyte Sucrose solution (400 μS/cm) DEP: 5.2 Vpp, 30 kHz, twDEP: 5.6 Vpp, 350 kHz, unknown time IDEs (10 μm/10 μm) — 30 DEP + DEP (sine + sine superposition) Viable/non-viable yeast cells Diluted PBS (600 μS/cm) DEP (focusing): 3.39 Vrms, 60&90 kHz, DEP (sorting): 4.38 Vrms, 5 MHz, 20 s Liquid electrodes chambers (20 μm/20 μm) Ti/Pt 31 DEP + electrorotaion (sine + sine superposition) T lymphocyte Inositol-added medium (326 μS/cm) DEP (trap): 2 Vpp, 20 kHz, electrorotation: 0.4 Vpp, 100 kHz, 30 s 3D octode (top–bottom quadrupoles; 50 μm gap) Cr/Au 32 Pulsed DEP (sine + on-off cycles) 3-μm-diam. PS beads DI water Sine: 20 Vpp, 10 MHz, on-off: 0.3 Hz, 10 s IDEs (30 μm/30 μm) ITO 33 Pulsed DEP (sine + on-off cycles) Single lambda-DNA DI water (1.1 μS/cm) Sine: 20 Vpp, 1 MHz, on-off: 20 Hz, 1–10 s Coplanar (10 μm gap) Silicon nanotweezers 34 Pulsed DEP (sine + square superposition) 10-μm-diam. PS beads DI water (2 μS/cm) Sine: 10 Vpp, 50 kHz, square: 10 Vpp, 2 MHz, 1 s Top–bottom ITO 35 DEP + EO via Signal Superposition DEP + EO (sine + sine superposition) E. coli K-12/1-μm-diam.…”

Dielectrophoresis for Biomedical Sciences Applications: A Review

“…On the other hand, DEP force, generated by two combine electrodes stretching system, was used to immobilized λ DNA molecules [168]. In addition, the DEP technique was successfully used to trap a single DNA molecule with a silicon nanotweezers [170]. In [171], an immunodevice was developed for capturing DNAs by combining microparticle-based immunoreactions with n-DEP accumulation and trapping.…”