Light-activated electrochemistry on alkyne-terminated Si(100) surfaces towards solution-based redox probes

Wu, Yanfang; Kashi, Mehran B.; Yang, Ying; Ciampi, Simone; Tilley, Richard D.; Gooding, J. Justin

doi:10.1016/j.electacta.2016.07.120

Cited by 13 publications

(6 citation statements)

References 30 publications

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“…Such a consistency which is attributed to the short diffusion length of holes in hematite is what has never been obtained from other n-type semiconductors considered for LAE before. In the case of c-Si, the virtual electrode estimated by scanning electrochemical microscopy is 5 times larger than the light pointer . The spatial resolution of QD-based LAE has not been investigated experimentally yet.…”

Section: Resultsmentioning

confidence: 99%

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Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes

Seo

Lim

Lee

et al. 2018

ACS Appl. Mater. Interfaces

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Light addressable/activated electrochemistry (LAE) has recently attracted attention as it can provide spatially resolved electrochemical information without using pre-patterned electrodes whose sizes and positions are unchangeable. Here, we propose hematite (α-FeO) as the photoanode for LAE, which does not require any sort of surface modification for protection or facilitating charge transfer. As experimentally confirmed with various redox species, hematite is stable enough to be used for repetitive electroanalytical measurements. More importantly, it offers exceptionally high spatial resolution so that the "virtual electrode" is exactly as large as the light spot owing to the short diffusion length of the minority carriers. Quantitative analysis of dopamine in this study shows that the hematite-based photoanode is a promising platform for many potential LAE applications including spatially selective detection of oxidizable biomolecules.

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Section: Resultsmentioning

confidence: 99%

“…In the case of c-Si, the virtual electrode estimated by scanning electrochemical microscopy is 5 times larger than the light pointer. 31 The spatial resolution of QDbased LAE has not been investigated experimentally yet.…”

Section: ■ Results and Discussionmentioning

confidence: 99%

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes

Seo

Lim

Lee

et al. 2018

ACS Appl. Mater. Interfaces

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“…The attribution arises from our previous observation that redox species physisorb onto 1,8-nonadiyne-derived monolayers and act as redox mediators for solubilized species. 45 Such behavior is shown in Figure S9, with a linear dependence of i pc on ν 1/2 for cyclic voltammograms registered with monolayer-protected Si(100) in electrolytes containing solubilized AQMS. Figures 1 and S9 show that, after both BSA and OEG 6 are added to the surface, the electroactivity of solubilized AQMS is still observed prior to hybridization.…”

Section: ■ Discussionmentioning

confidence: 80%

“…It is hypothesized that mediated electron transfer plays a role in the electroactivity observed here for both the OEG 6 and the BSA layers. The attribution arises from our previous observation that redox species physisorb onto 1,8-nonadiyne-derived monolayers and act as redox mediators for solubilized species . Such behavior is shown in Figure S9, with a linear dependence of i pc on ν 1/2 for cyclic voltammograms registered with monolayer-protected Si(100) in electrolytes containing solubilized AQMS.…”

Section: Discussionmentioning

confidence: 81%

DNA-Hybridization Detection on Si(100) Surfaces Using Light-Activated Electrochemistry: A Comparative Study between Bovine Serum Albumin and Hexaethylene Glycol as Antifouling Layers

et al. 2018

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Light can be used to spatially resolve electrochemical measurements on a semiconductor electrode. This phenomenon has been explored to detect DNA hybridization with light-addressable potentiometric sensors and, more recently, with light-addressable amperometric sensors based on organic-monolayer-protected Si(100). Here, a contribution to the field is presented by comparing sensing performances when bovine serum albumin (BSA) and hexaethylene glycol (OEG) are employed as antifouling layers that resist nonspecific adsorption to the DNA-modified interface on Si(100) devices. What is observed is that both sensors based on BSA or OEG initially allow electrochemical distinction among complementary, noncomplementary, and mismatched DNA targets. However, only surfaces based on OEG can sustain electroactivity over time. Our results suggest that this relates to accelerated SiO formation occasioned by BSA proteins adsorbing on monolayer-protected Si(100) surfaces. Therefore, DNA biosensors were analytically explored on low-doped Si(100) electrodes modified on the molecular level with OEG as an antifouling layer. First, light-activated electrochemical responses were recorded over a range of complementary DNA target concentrations. A linear semilog relation was obtained from 1.0 × 10 to 1.0 × 10 mol L with a correlation coefficient of 0.942. Then, measurements with three independent surfaces indicated a relative standard deviation of 4.5%. Finally, selectivity tests were successfully performed in complex samples consisting of a cocktail mixture of four different DNA sequences. Together, these results indicate that reliable and stable light-activated amperometric DNA sensors can be achieved on Si(100) by employing OEG as an antifouling layer.

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“…Several published reports dealing with the surface reactivity of silicon crystals carry clear evidence of a pair of adventitious redox waves, either disregarded or tentatively associated with the adsorption of a target molecule. − Herein we demonstrate how to systematically reproduce and amplify this parasitic signal. We bring evidence of this signal being the reversible electrochemical conversion of silica to silicon, taking place at the buried silicon–silica interface in correspondence of ubiquitous highly conductive crystal defects.…”

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confidence: 87%

Common Background Signals in Voltammograms of Crystalline Silicon Electrodes are Reversible Silica–Silicon Redox Chemistry at Highly Conductive Surface Sites

et al. 2020

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The electrochemical reduction of bulk silica, due to its high electrical resistance, is of limited viability, namely, requiring temperatures in excess of 850 °C. By means of electrochemical and electrical measurements in atomic force microscopy, we demonstrate that at a buried interface, where silica has grown on highly conductive Si(110) crystal facets, the silica–silicon conversion becomes reversible at room temperature and accessible within a narrow potential window. We conclude that parasitic signals commonly observed in voltammograms of silicon electrodes originate from silica–silicon redox chemistry. While these findings do not remove the requirement of high temperature toward bulk silica electrochemical reduction, they redefine for silicon the potential window free from parasitic signals and, as such, significantly restrict the conditions where electroanalytical methods can be applied to the study of silicon surface reactivity.

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Light-activated electrochemistry on alkyne-terminated Si(100) surfaces towards solution-based redox probes

Cited by 13 publications

References 30 publications

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes

DNA-Hybridization Detection on Si(100) Surfaces Using Light-Activated Electrochemistry: A Comparative Study between Bovine Serum Albumin and Hexaethylene Glycol as Antifouling Layers

Common Background Signals in Voltammograms of Crystalline Silicon Electrodes are Reversible Silica–Silicon Redox Chemistry at Highly Conductive Surface Sites

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Light-activated electrochemistry on alkyne-terminated Si(100) surfaces towards solution-based redox probes

Cited by 13 publications

References 30 publications

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe2O3) Photoanodes

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe2O3) Photoanodes

DNA-Hybridization Detection on Si(100) Surfaces Using Light-Activated Electrochemistry: A Comparative Study between Bovine Serum Albumin and Hexaethylene Glycol as Antifouling Layers

Common Background Signals in Voltammograms of Crystalline Silicon Electrodes are Reversible Silica–Silicon Redox Chemistry at Highly Conductive Surface Sites

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Product

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Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes

Robust and High Spatial Resolution Light Addressable Electrochemistry Using Hematite (α-Fe₂O₃) Photoanodes