Nanomechanical Transduction Research Articles

Rock the nucleus: significantly enhanced nuclear membrane permeability and gene transfection by plasmonic nanobubble induced nanomechanical transduction.

Efficient delivery to the cell nucleus remains a significant challenge for many biomolecules, including anticancer drugs, proteins and DNAs. Despite numerous attempts to improve nuclear import including the use of nuclear localization signal (NLS) peptides and nanoparticle carriers, they are limited by the nanoparticle size, conjugation method, dependence on the functional nuclear import and intracellular trafficking mechanisms. To overcome these limitations, here we report that the nanomechanical force from plasmonic nanobubbles increases nuclear membrane permeability and promotes universal uptake of macromolecules into the nucleus, including macromolecules that are larger than the nuclear pore complex and would otherwise not enter the nucleus. Importantly, we show that plasmonic nanobubble-induced nanomechanical transduction significantly improves gene transfection and protein expression, compared to standard electroporation treatment alone. This novel nanomechanical transduction increases the size range and is broadly applicable for macromolecule delivery to the cell nucleus, leading to new opportunities and applications including for gene therapy and anticancer drug delivery.

Photochemistry: Solar‐Powered Nanomechanical Transduction from Crystalline Molecular Rotors (Adv. Mater. 24/2013)

Photochemistry: Solar‐Powered Nanomechanical Transduction from Crystalline Molecular Rotors (Adv. Mater. 24/2013)

Solar‐Powered Nanomechanical Transduction from Crystalline Molecular Rotors

A photoinduced solid-state SO₂ isomerism drives a larger mechanical change (benzene-ring rotation) in a neighbouring ion (i.e., the system acts as a solar-powered molecular transducer). The ring rotation and SO₂ photoisomerisation are observed using in situ X-ray crystallography and are controllable, reproducible, and metastable at low temperatures. This discovery presents a new range of materials for solar-energy-based molecular transduction.

Nanomechanical Silicon Resonators with Intrinsic Tunable Gain and Sub-nW Power Consumption

Nanoelectromechanical systems (NEMS) as integrated components for ultrasensitive sensing, time keeping, or radio frequency applications have driven the search for scalable nanomechanical transduction on-chip. Here, we present a hybrid silicon-on-insulator platform for building NEM oscillators in which fin field effect transistors (FinFETs) are integrated into nanomechanical silicon resonators. We demonstrate transistor amplification and signal mixing, coupled with mechanical motion at very high frequencies (25-80 MHz). By operating the transistor in the subthreshold region, the power consumption of resonators can be reduced to record-low nW levels, opening the way for the parallel operation of hundreds of thousands of NEM oscillators. The electromechanical charge modulation due to the field effect in a resonant transistor body constitutes a scalable nanomechanical motion detection all-on-chip and at room temperature. The new class of tunable NEMS represents a major step toward their integration in resonator arrays for applications in sensing and signal processing.

Translating Biomolecular Recognition into Nanomechanics

We report the specific transduction, via surface stress changes, of DNA hybridization and receptor-ligand binding into a direct nanomechanical response of microfabricated cantilevers. Cantilevers in an array were functionalized with a selection of biomolecules. The differential deflection of the cantilevers was found to provide a true molecular recognition signal despite large nonspecific responses of individual cantilevers. Hybridization of complementary oligonucleotides shows that a single base mismatch between two 12-mer oligonucleotides is clearly detectable. Similar experiments on protein A-immunoglobulin interactions demonstrate the wide-ranging applicability of nanomechanical transduction to detect biomolecular recognition.