Mark Hartman - Academia.edu (original) (raw)

Papers by Mark Hartman

2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, 2011

Electrochemical interface layer overcharging is experimentally demonstrated at planar MOS sensor ... more Electrochemical interface layer overcharging is experimentally demonstrated at planar MOS sensor interfaces by controlling the surface charge through nonvolatile charge injection. The electric field across the solid-fluid interface is modulated upon floating-gate program/erase and leads to electrolytic charge reversal, for which an analytical model is derived. This electrofluidic gating effect is further used to repel adsorbed DNA, realizing an electrical surface refreshable biosensor. Quasi-static and impedimetric measurements are presented for validation.

Nature Nanotechnology, 2008

Highly ordered arrays of nanoparticles exhibit many properties that are not found in their disord... more Highly ordered arrays of nanoparticles exhibit many properties that are not found in their disordered counterparts. However, these nanoparticle superlattices usually form in a far-from-equilibrium dewetting process, which precludes the use of conventional patterning methods owing to a lack of control over the local dewetting dynamics. Here, we report a simple yet efficient approach for patterning such superlattices that involves moulding microdroplets containing the nanoparticles and spatially regulating their dewetting process. This approach can provide rational control over the local nucleation and growth of the nanoparticle superlattices. Using DNA-capped gold nanoparticles as a model system, we have patterned nanoparticle superlattices over large areas into a number of versatile structures with high degrees of internal order, including single-particle-width corrals, single-particle-thickness microdiscs and submicrometre-sized 'supra-crystals'. Remarkably, these features could be addressed by micropatterned electrode arrays, suggesting potential applications in bottom-up nanodevices.

Angewandte Chemie International Edition, 2013

ABSTRACT Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stab... more ABSTRACT Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stability. These thermostable DNA nanostructures were then utilized as modular primers in polymerase chain reaction (PCR; see picture), thus enabling the production of multifunctionalized and branched PCR products for multiplexed detection and hydrogel formation.

Angewandte Chemie International Edition, 2010

The crystallization of organically capped nanoparticles, unlike the hard-sphere crystallization o... more The crystallization of organically capped nanoparticles, unlike the hard-sphere crystallization of atoms, molecules, or conventional colloids, is a "soft process" in which the deformation of organic layers (soft coronae) unavoidably occurs. Despite previous efforts that focused mainly on structures at thermodynamic equilibrium, it is not known how soft coronae deform dynamically in this soft-crystallization process. Here, using DNA-capped nanoparticles as a model system, we have probed in real time and in situ the entire drying-mediated soft-crystallization process by synchrotronbased small-angle X-ray scattering (SAXS). Notably, in our DNA-based approach the known strategy of programmable crystal formation is combined with drying-mediated self-assembly. Our dynamic studies demonstrate that our soft crystals have continuously scalable crystalline states with a gradual transition from "wet crystals" to "dry crystals". We have found that the drying-mediated deformation of DNA molecules is elastic in accordance with an entropic spring model, which can also be applied in general to the drying-mediated self-assembly of other organically capped inorganic nanoparticles.

2011 16th International Solid-State Sensors, Actuators and Microsystems Conference, 2011

Electrochemical interface layer overcharging is experimentally demonstrated at planar MOS sensor ... more Electrochemical interface layer overcharging is experimentally demonstrated at planar MOS sensor interfaces by controlling the surface charge through nonvolatile charge injection. The electric field across the solid-fluid interface is modulated upon floating-gate program/erase and leads to electrolytic charge reversal, for which an analytical model is derived. This electrofluidic gating effect is further used to repel adsorbed DNA, realizing an electrical surface refreshable biosensor. Quasi-static and impedimetric measurements are presented for validation.

Nature Nanotechnology, 2008

Highly ordered arrays of nanoparticles exhibit many properties that are not found in their disord... more Highly ordered arrays of nanoparticles exhibit many properties that are not found in their disordered counterparts. However, these nanoparticle superlattices usually form in a far-from-equilibrium dewetting process, which precludes the use of conventional patterning methods owing to a lack of control over the local dewetting dynamics. Here, we report a simple yet efficient approach for patterning such superlattices that involves moulding microdroplets containing the nanoparticles and spatially regulating their dewetting process. This approach can provide rational control over the local nucleation and growth of the nanoparticle superlattices. Using DNA-capped gold nanoparticles as a model system, we have patterned nanoparticle superlattices over large areas into a number of versatile structures with high degrees of internal order, including single-particle-width corrals, single-particle-thickness microdiscs and submicrometre-sized 'supra-crystals'. Remarkably, these features could be addressed by micropatterned electrode arrays, suggesting potential applications in bottom-up nanodevices.

Angewandte Chemie International Edition, 2013

ABSTRACT Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stab... more ABSTRACT Chemical cross-linking was used to prepare DNA nanostructures with enhanced thermal stability. These thermostable DNA nanostructures were then utilized as modular primers in polymerase chain reaction (PCR; see picture), thus enabling the production of multifunctionalized and branched PCR products for multiplexed detection and hydrogel formation.

Angewandte Chemie International Edition, 2010

The crystallization of organically capped nanoparticles, unlike the hard-sphere crystallization o... more The crystallization of organically capped nanoparticles, unlike the hard-sphere crystallization of atoms, molecules, or conventional colloids, is a "soft process" in which the deformation of organic layers (soft coronae) unavoidably occurs. Despite previous efforts that focused mainly on structures at thermodynamic equilibrium, it is not known how soft coronae deform dynamically in this soft-crystallization process. Here, using DNA-capped nanoparticles as a model system, we have probed in real time and in situ the entire drying-mediated soft-crystallization process by synchrotronbased small-angle X-ray scattering (SAXS). Notably, in our DNA-based approach the known strategy of programmable crystal formation is combined with drying-mediated self-assembly. Our dynamic studies demonstrate that our soft crystals have continuously scalable crystalline states with a gradual transition from "wet crystals" to "dry crystals". We have found that the drying-mediated deformation of DNA molecules is elastic in accordance with an entropic spring model, which can also be applied in general to the drying-mediated self-assembly of other organically capped inorganic nanoparticles.