Nanostructure‐Driven Analyte–Interface Electron Transduction: A General Approach to Sensor and Microreactor Design

Gole, James L.; Goude, Eddie C.; Laminack, William

doi:10.1002/cphc.201100712

Cited by 27 publications

(123 citation statements)

References 30 publications

Supporting

Mentioning

121

Contrasting

Order By: Relevance

“…By depositing metal oxide nanostructure islands to the PS interface, shown schematically in Figure 1, the response of the sensor can be enhanced or diminished [32]. The Inverse Hard/Soft Acid/ Base (IHSAB) model, explains this phenomenon by linking chemical selectivity and the balance of electron transduction and chemisorption [5,[31][32][33] with the sensor response mechanisms.…”

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

“…The Inverse Hard/Soft Acid/ Base (IHSAB) model, explains this phenomenon by linking chemical selectivity and the balance of electron transduction and chemisorption [5,[31][32][33] with the sensor response mechanisms. The IHSAB model predicts the interaction of acidic, basic, and amphoteric gas analytes with the nanostructure treated PS sensor interfaces.…”

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

“…As the HOMO (donor)-LUMO (acceptor) energy gap decreases, there can be more charge transfer between the and current density. The details of the micro-fabrication processes are straightforward and are described elsewhere [5,31,32].…”

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

“…As dictated by the scale and following the IHSAB model of interactions, PS deposited with Au x O nanostructures will produce the largest response to NH 3 and PS deposited with TiO 2 will produce the largest response to CO. Within the IHSAB framework, metal/metal oxide nanostructure depositions can be selected for the PS sensor interface to create a predictable range of sensitivities for various gases [5,[31][32][33]. The relative responses have observed for select n-type and p-type systems.…”

Section: And Does Not Demand That the Nanostructured Islands Be Placementioning

confidence: 99%

See 3 more Smart Citations

Nanostructure directed interfaces created from nanoparticle island sites deposited to microporous arrays and forming sensor platforms

Gole¹,

Laminack²,

Boudreaux³

2017

Front Nanosci Nanotech

Self Cite

View full text Add to dashboard Cite

Novel nanostructured island sites are made to decorate a microporous/nanoporous array. These island sites are formed from a variety of easily produced nanostructured metal oxides deposited from solution. Sensor platforms are distinct from and do not require film-based coating. The nanostructure directing acidic metal oxide sites which vary in their Lewis acidity decorate micropores and control the electron transduction process. The interaction of analytes with these island sites varies in a predictable manner and can be modified through in-situ functionalization of their Lewis acidity. The microporous structure allows rapid Fickian diffusion of analytes to the active nanostructure island sites whose reversible interaction dominates the sensor response as it requires low energy consumption. Highly accurate repeat depositions are not required. We require that the island sites are deposited at sufficiently low concentration so as not to interact electronically with each other. The response time of these interfaces is more rapid than film-based depositions, which require a more lengthy diffusion time. The sensors are reversible. The nanoporous structure prevents sintering of these island centers at elevated temperatures. The concentration of detection centers can be made to produce an optimum matrix of enhanced sensor responses, force a dominant distinct analyte-interface physisorption (rather than chemisorption). The produced semiconductor interface is easily functionalized to create an enhanced range of nanoparticle semiconductor sites. The matrix provides a sensitive means of transferring electrons that are easily detected. The sensors operate at room temperature as well as elevated temperatures. Low energy magnetic field signal enhancement can be achieved with transition metals. Contaminated sensors can be readily rejuvenated. Pulsed mode operation ensures low analyte consumption and high analyte selectivity and further provides the ability to rapidly assess false positive signals using Fast Fourier Transfer techniques, Solar pumped sensors requiring low light levels (≤ 1 Watt) have been demonstrated. Water vapor contamination can be greatly if not entirely reduced. The modelling of sensor response with a new Fermi energy distribution -based response isotherm is found to be superior to other isotherms. Sensors operate can be made to operate efficiently for two gases simultaneously. Modes of extending these studies to multiple gas arrays are considered.

show abstract

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

Section: Inverse Hard/soft Acid/base Conceptmentioning

confidence: 99%

Section: And Does Not Demand That the Nanostructured Islands Be Placementioning

confidence: 99%

See 2 more Smart Citations

Nanostructure directed interfaces created from nanoparticle island sites deposited to microporous arrays and forming sensor platforms

Gole¹,

Laminack²,

Boudreaux³

2017

Front Nanosci Nanotech

Self Cite

View full text Add to dashboard Cite

show abstract

“…This initial study makes use of the Co(II)Cl 2 Á6H 2 O complex 10 so as to deposit Co(II) in the pores of a porous a) silicon matrix 5,11 and 10 nm iron oxide nanoparticles so as to deposit Fe(II) in the pores of the porous silicon (PS) matrix. 5,11 In this study, we make use of the fact that an analyte can donate electrons to a "p-type" PS semiconductor surface and these electrons combine with holes, thus reducing the number of majority charge carriers. This leads to an increased resistance.…”

Section: Introductionmentioning

confidence: 99%

Magnetically induced enhancement of reversibly responding conductometric sensors

Baker

Laminack

Tune

et al. 2014

Journal of Applied Physics

Self Cite

View full text Add to dashboard Cite

Small magnetic fields are found to greatly enhance the reversible room temperature conductometric responses of n and p- type porous silicon (PS) interfaces, treated with nanostructured island sites containing paramagnetic Co(II) and Fe(II). At concentrations sufficiently low so as to avoid cross talk between the nanostructured island sites, the response to NO concentrations demonstrates the significant effect which the Co(II) and Fe(II) have on the decorated extrinsic semiconductor majority charge carriers as they direct a dominant electron transduction process for reversible electron transduction and chemical sensing (Inverse Hard and Soft acid/base principle) in the absence of significant chemical bond formation. Co(II) and Fe(II) oxide sites enhance response and provide a means for small magnetic fields to interact with and enhance the sensor interface response. For p-type systems, the interaction is with small virtually constant thermal electron populations lying above the Fermi energy at 0 K. The electron removal rate increases with magnetic field strength. At the highest magnetic fields and NO analyte concentrations the available electron population is depleted, and the response to the analyte decreases at higher concentrations. At lower magnetic fields (<1000 G), the response faithfully follows concentration. For n-type systems, the magnetic field interaction increases resistance. This increase in response may be attributed to the interaction with donor levels ∼0.025 eV below the conduction band. A substantial enhancement of sensor response relative to that for the Co(II) and Fe(II) treated PS interfaces is observed, with the introduction of a small magnetic field greatly increasing an already enhanced conductometric response.

show abstract

Light Enhanced Electron Transduction and Amplified Sensing at a Nanostructure Modified Semiconductor Interface

Laminack

Gole

2013

Adv Funct Materials

Self Cite

View full text Add to dashboard Cite

Visible and UV light are demonstrated to significantly enhance the sensing properties of an n‐type porous silicon (PS) extrinsic semiconductor interface to which TiO2 and titanium oxynitride (TiO2‐xNx) photocatalytic nanostructures are fractionally deposited. The acid/base chemistry of NH3, a moderately strong base, and NO2, a moderately strong acid, couples to the majority charge carriers of the doped semiconductor as the strong acid (TiO2) enhances the extraction of electrons from NH3, and the more basic TiO2‐xNx decreases the efficiency of electron extraction relative to the untreated interface. In contrast, NO2 and a TiO2 or TiO2‐xNx nanostructure‐decorated PS interface compete for the available electrons leading to a distinct time dependent electron transduction dynamics as a function of TiO2 and TiO2‐xNx concentration. Only small concentrations of TiO2 and its oxynitride and no self‐assembly are required to enhance the response of the decorated interface. With light intensities of less than a few lumens/cm2‐sterad‐nm, responses are enhanced by up to 150% through interaction with visible (and UV) radiation. These light intensities should be compared to the sun's radiation level, ≈500 lumens/cm2‐sterad‐nm suggesting the possibility of solar pumped sensors. The observed behavior in these systems is largely explained by the recently developed Inverse Hard/Soft Acid/Base (IHSAB) concept.

show abstract

Nanostructure‐Driven Analyte–Interface Electron Transduction: A General Approach to Sensor and Microreactor Design

Cited by 27 publications

References 30 publications

Nanostructure directed interfaces created from nanoparticle island sites deposited to microporous arrays and forming sensor platforms

Nanostructure directed interfaces created from nanoparticle island sites deposited to microporous arrays and forming sensor platforms

Magnetically induced enhancement of reversibly responding conductometric sensors

Light Enhanced Electron Transduction and Amplified Sensing at a Nanostructure Modified Semiconductor Interface

Contact Info

Product

Resources

About