Enzymic substrate determination in closed flow-through systems by sample injection and amperometric monitoring of dissolved oxygen levels

Wolff, Charles‐Michel; Mottola, Horacio A.

doi:10.1021/ac50023a026

Cited by 48 publications

(15 citation statements)

References 15 publications

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“…All solutions used in the sensor development were prepared with deionized water (conductivity less than 1 µS·cm -1 range according to [30]. Oxygen was measured amperometrically using a set-up that the two signals are shifted about 250 mV due to the use of different reference electrodes.…”

Section: Reagents and Instrumentationmentioning

confidence: 99%

Profiling of oxygen in biofilms using individually addressable disk microelectrodes on a microfabricated needle

et al. 2014

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A novel microelectrode array sensor was fabricated using MEMS technology on a needle, and then applied to real-time measurement of dissolved oxygen (DO) inside biofilms. The sensor consists of eleven gold disk microelectrodes and a rectangular auxiliary electrode along them and an external & internal reference electrode. Three kinds of sensors were designed and their responses were characterized and evaluated under various environmental conditions. The arrays exhibit a linear response to DO in the 0 -8 mg L -1 concentration range in water, high sensitivity, repeatability, and low limits of detection (< 0.11 mg L -1 ) and quantification (0.38 mg L -1 ). The sensors were then validated against a commercial Clark-type microelectrode and applied to profiling of DO in a heterotrophic biofilm cultivated in a flat-plate bioreactor. It is shown that the sensor array can provide a multipoint, simultaneous snapshot profile of DO inside a biofilm with high spatial resolution due to its micrometric dimensions. We conclude that this new sensor array represents a powerful tool for sensing of DO biofilms and in numerous bioprocesses.

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Section: Reagents and Instrumentationmentioning

confidence: 99%

Profiling of oxygen in biofilms using individually addressable disk microelectrodes on a microfabricated needle

et al. 2014

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“…For this purpose, the sensor was polarized against a reference system at the overall oxygen reduction potential. Several works [35,36] have suggested using an electrochemical potential between −800 and −900 mV (vs. Ag/AgCl). Nevertheless, a comprehensive assessment between oxygen reduction potential and DO sensitivity presented in Moya et al [15] highlighted that optimal performance is obtained when −850 mV (vs. Ag/AgCl) is used.…”

Section: Methodsmentioning

confidence: 99%

A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling

Guimerà

Moya

Dorado

et al. 2019

Sensors

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A novel sensing device for simultaneous dissolved oxygen (DO) and pH monitoring specially designed for biofilm profiling is presented in this work. This device enabled the recording of instantaneous DO and pH dynamic profiles within biofilms, improving the tools available for the study and the characterization of biological systems. The microsensor consisted of two parallel arrays of microelectrodes. Microelectrodes used for DO sensing were bare gold electrodes, while microelectrodes used for pH sensing were platinum-based electrodes modified using electrodeposited iridium oxide. The device was fabricated with a polyimide (Kapton®) film of 127 µm as a substrate for minimizing the damage caused on the biofilm structure during its insertion. The electrodes were covered with a Nafion® layer to increase sensor stability and repeatability and to avoid electrode surface fouling. DO microelectrodes showed a linear response in the range 0–8 mg L−1, a detection limit of 0.05 mg L−1, and a sensitivity of 2.06 nA L mg−1. pH electrodes showed a linear super-Nernstian response (74.2 ± 0.7 mV/pH unit) in a wide pH range (pH 4−9). The multi-analyte sensor array was validated in a flat plate bioreactor where simultaneous and instantaneous pH and DO profiles within a sulfide oxidizing biofilm were recorded. The electrodes spatial resolution, the monitoring sensitivity, and the minimally invasive features exhibited by the proposed microsensor improved biofilm monitoring performance, enabling the quantification of mass transfer resistances and the assessment of biological activity.

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“…The generating of reagents in FIA systems can be also made using electrodialysis [31]. Another concept of limitation of the large consumption of reagents is design of closed-loop FIA systems with circulation and eventual regeneration of liquid reagents [32,33].…”

Section: Injection Methods Of Flow Analysismentioning

confidence: 99%

Flow Analysis as Advanced Branch of Flow Chemistry

Trojanowicz¹

2013

Mod Chem Appl

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The effectiveness of the carrying out chemical reactions, especially in terms of syntheses conducted in the laboratory or on a technological scale, is a primary target of the optimization of chemical conditions and physicochemical parameters of a given process. Since the publication of pioneering works in the beginning of 1970s, it is an increasingly accepted concept that carrying out chemical reactions in continuously flowing streams rather than in batch configuration has numerous advantages, hence flow chemistry can be at present considered as a separate and rapidly increasing area of modern chemistry. Four decades of the development of those methods resulted in thousands of original research works, numerous reported attractive technologies, and also in the presence of numerous specialized instruments on the market.

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Enzymic substrate determination in closed flow-through systems by sample injection and amperometric monitoring of dissolved oxygen levels

Cited by 48 publications

References 15 publications

Profiling of oxygen in biofilms using individually addressable disk microelectrodes on a microfabricated needle

Profiling of oxygen in biofilms using individually addressable disk microelectrodes on a microfabricated needle

A Minimally Invasive Microsensor Specially Designed for Simultaneous Dissolved Oxygen and pH Biofilm Profiling

Flow Analysis as Advanced Branch of Flow Chemistry

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