The influence of the lipophilic base in solid state optical pCO2 sensors

Schröder, Claudia R.; Klimant, Ingo

doi:10.1016/j.snb.2004.11.019

Cited by 18 publications

(11 citation statements)

References 23 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…When ethyl cellulose (ethoxyl con- tent 46%) is applied as the polymer membrane, additional TOAOH is needed to neutralize the acid residues in the polymer matrix. The smallest amount of TOAOH necessary was found to be 8×10 -2 mol base/kg dry ethyl cellulose to initially deprotonate the indicator dye completely (Schröder and Klimant 2005). Higher organic base content may stabilize the deprotonated form of the indicator ion pair in the membrane and prolong the sensor lifetime (Neurauter et al 2000).…”

Section: Assessment and Discussionmentioning

confidence: 96%

“…Temperature dependency and interferences-Solid state pCO 2 sensors are known to have a strong dependency on tempera- ture (Schröder and Klimant 2005;Zhu et al 2006a). Therefore, the effect of temperature on the proposed pCO 2 planar fluorosensor was evaluated by measuring sensor signals in borate buffer solutions saturated by pure N 2 and N 2 + 10 matm pCO 2 at various temperatures.…”

Section: Assessment and Discussionmentioning

confidence: 99%

See 1 more Smart Citation

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments

Zhu

Aller

2010

Limnology & Ocean Methods

View full text Add to dashboard Cite

Marine sediments play critical roles in the global carbon cycle, including the remineralization of organic carbon and the dissolution or precipitation of CaCO 3 , processes which can produce or consume CO 2 , HCO 3 -, CO 3 2-, and H + (Emerson and Hedges 2003;Martin and Sayles 1994). As a consequence, deposits near the sediment-water surface (0-5 cm depth) are typically characterized by steep vertical gradients of CO 2 , pH, and O 2 (Cai and Reimers 1993;Reimers et al. 1996;Hales and Emerson 1997;de Beer et al. 1997). This zone is also commonly inhabited by macrofauna. The feeding, burrowing, and irrigation activities of these bottom-dwelling animals create three-dimensional and time-dependent patterns of biogeochemical reactions within sediments, and greatly complicate quantification and estimation of material fluxes (Aller 1980(Aller , 2001. In-situ, high-resolution measurements of the distributions of pCO 2 are thus essential for conceptualizing and modeling heterogeneous biogeochemical reactions, microbial metabolism, and solute transport in bioturbated deposits. Recently, we reported on a planar pCO 2 fluorosensor, which allows high-resolution two-dimensional mapping of pCO 2 in sediments and overlying water (Zhu et al. 2006a). This sensor uses 8-hydroxy-1,3,6-pyrenetrisulfonic acid trisodium salt (HPTS) as the fluorescence indicator, ethyl cellulose as polymer matrix, and has a response time of ~2.5 min and a recovery time of ~5 min (over 0-5 matm). While a significant advance, it cannot respond rapidly enough to measure CO 2 dynamics associated with high frequency transport-reaction processes such as burrow irrigation. To better study real-time pCO 2 variation in bioturbated sediment, we designed and report here on an improved planar pCO 2 sensor with a faster response.The first pCO 2 sensor was developed in 1957 based on potentiometric electrodes (Stow et al. 1957;Severinghaus and Bradley 1958). This type of pCO 2 sensor combines a pH electrode embedded within a bicarbonate buffer-filled compartment that interacts with the environment through a gas-permeable membrane. Such sensors have been used to profile pCO 2 distributions vertically in marine sediments and to study biogeochemical reactions near the sediment surface (Cai and Reimers 1993; Zhao and Cai 1997). They are limited by relatively slow response, short lifetime, and an arduous fabrica-A rapid response, planar fluorosensor for measuring twodimensional pCO 2 distributions and dynamics in marine sediments Qingzhi Zhu* and Robert C. AllerSchool of Marine and Atmospheric Sciences, Stony Brook University, Stony Brook, NY 11794-5000, USA Abstract CO 2 distributions in marine sediments are closely coupled to early diagenetic reactions and transport processes. An existing planar optode designed to measure pCO 2 in sediments and overlying water was modified to substantially lower response times and to allow for enhanced resolution of CO 2 dynamics. Sensing foils are fabricated by entrapping fluorescent indicator 8-hydroxy-1,3,6-pyrenetrisulfonic acid-tet...

show abstract

Section: Assessment and Discussionmentioning

confidence: 96%

Section: Assessment and Discussionmentioning

confidence: 99%

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments

Zhu

Aller

2010

Limnology & Ocean Methods

View full text Add to dashboard Cite

show abstract

“…reference and indicator) will most likely not show such insensitivity to temperature variations due to potential differences in the temperature response of the two dyes. The fluorescein derivatives DHFA and DHFAE also exhibited a decrease in luminescent intensity with increasing temperature while their apparent pK a s were observed to increase [131]. These counteracting trends largely eliminated the need for temperature compensation in the range of pH 5.5-8 for temperatures deviations of less than 5 C from the calibration temperature.…”

Section: Interferencesmentioning

confidence: 94%

“…The addition of the base serves to neutralize acidic residues in the polymer and to create a buffer, thus stabilizing the deprotonated form of the pH indicator ion pair in the matrix [129,130]. The sensitivity of pCO 2 sensors generally depends on the apparent pK a value of the indicator in the sensor matrix, on the CO 2 permeability of the polymer and on the amount and nature of the lipophilic buffer substance added [129,131]. The HPTS(TOA) ion pair, immobilized in ethyl cellulose, is to date the only indicator reported to be used for planar optode imaging of pCO 2 [20,72].…”

Section: Pco 2 Nh 4 + and Sulphide Indicatorsmentioning

confidence: 99%

“…Leaching of O 2 indicators from polystyrene is reported to be no problem due to the high solubility of the indicator in this matrix [208]. However, indicator leaching from pH sensors is more problematic, especially from hydrogel matrices [124,131]. Leaching of DHFAE and DHFA from Hydromed D4 resulted in a decrease in sensor absorbance of 11.2% and 18.1%, respectively, during a 10 day period.…”

Section: Sensor Stabilitymentioning

confidence: 99%

See 1 more Smart Citation

Two decades of chemical imaging of solutes in sediments and soils – a review

Santner

Larsen

Kreuzeder

et al. 2015

Analytica Chimica Acta

170

130

View full text Add to dashboard Cite

The increasing appreciation of the small-scale (sub-mm) heterogeneity of biogeochemical processes in sediments, wetlands and soils has led to the development of several methods for high-resolution two-dimensional imaging of solute distribution in porewaters. Over the past decades, localised sampling of solutes (diffusive equilibration in thin films, diffusive gradients in thin films) followed by planar luminescent sensors (planar optodes) have been used as analytical tools for studies on solute distribution and dynamics. These approaches have provided new conceptual and quantitative understanding of biogeochemical processes regulating the distribution of key elements and solutes including O2, CO2, pH, redox conditions as well as nutrient and contaminant ion species in structurally complex soils and sediments. Recently these methods have been applied in parallel or integrated as so-called sandwich sensors for multianalyte measurements. Here we review the capabilities and limitations of the chemical imaging methods that are currently at hand, using a number of case studies, and provide an outlook on potential future developments for two-dimensional solute imaging in soils and sediments.

show abstract

Integrated waveguide sensor utilizing organic photodiodes

Lamprecht¹,

Kraker²,

Sagmeister³

et al. 2011

Physica Rapid Research Ltrs

View full text Add to dashboard Cite

We present a novel optical sensor platform, combining monolithically integrated ring‐like sensor waveguides together with ring‐shaped thin‐film organic photodiodes (OPDs) on one substrate. The OPDs serve as integrated light detectors, simplifying the detection system by minimizing the number of required optical components. The waveguide structures, including a means of coupling light in and out of the waveguides, serve as sensing elements. The functionality of the concept is demonstrated by an integrated carbon dioxide sensor, utilizing absorbance as sensing principle. The integrated optical sensor platform is suitable for the parallel detection of multiple parameters in a single sensor chip using sensor arrays. (© 2011 WILEY‐VCH Verlag GmbH & Co. KGaA, Weinheim)

show abstract

The influence of the lipophilic base in solid state optical pCO2 sensors

Cited by 18 publications

References 23 publications

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments

Two decades of chemical imaging of solutes in sediments and soils – a review

Integrated waveguide sensor utilizing organic photodiodes

Contact Info

Product

Resources

About

The influence of the lipophilic base in solid state optical pCO2 sensors

Cited by 18 publications

References 23 publications

A rapid response, planar fluorosensor for measuring two‐dimensional pCO2 distributions and dynamics in marine sediments

A rapid response, planar fluorosensor for measuring two‐dimensional pCO2 distributions and dynamics in marine sediments

Two decades of chemical imaging of solutes in sediments and soils – a review

Integrated waveguide sensor utilizing organic photodiodes

Contact Info

Product

Resources

About

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments

A rapid response, planar fluorosensor for measuring two‐dimensional pCO₂ distributions and dynamics in marine sediments