Thermal Biosensor and Microbiosensor Techniques

In this paper we describe a thermal biosensor with a flow injection analysis system for the determination of the chemical oxygen demand (COD) of water samples. Glucose solutions of different concentrations and actual water samples were tested, and their COD values were determined by measuring the heat generated when the samples passed through a column containing periodic acid. The biosensor exhibited a large linear range (5 to 3000 mg/L) and a low detection limit (1.84 mg/L). It could tolerate the presence of chloride ions in concentrations of 0.015 M without requiring a masking agent. The sensor was successfully used for detecting the COD values of actual samples. The COD values of water samples from various sources were correlated with those obtained by the standard dichromate method; the linear regression coefficient was found to be 0.996. The sensor is environmentally friendly, economical, and highly stable, and exhibits good reproducibility and accuracy. In addition, its response time is short, and there is no danger of hazardous emissions or external contamination. Finally, the samples to be tested do not have to be pretreated. These results suggest that the biosensor is suitable for the continuous monitoring of the COD values of actual wastewater samples.

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“…The FIA biosensor used in this study has been described elsewhere previously [25]. A schematic of the device setup is shown in Figure 1.…”

Section: Methodsmentioning

confidence: 99%

Rapid Determination of the Chemical Oxygen Demand of Water Using a Thermal Biosensor

Yao

Wang

Zhou

2014

Sensors

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“…The single‐channel Enzyme Thermistor device used in this study has been previously described . The setup consists of a peristaltic pump (Gilson Minipuls 2, Villiers‐le‐Bel, France) mounted with one tube for each channel, a pneumatic injection valve with a 100‐μL sample loop (Valco Instrument Co. Inc., Houston, TX, USA) and the Enzyme Thermistor instrument (Omik Bioscience AB, Lund, Sweden).…”

Section: Methodsmentioning

confidence: 99%

“…Our group has developed a flow‐injected thermal enzyme biosensor, the Enzyme Thermistor. This device detects the heat generated by enzymatic reactions to quantify the presence of specific analytes . To achieve real‐time monitoring, it was necessary to eliminate sample treatment.…”

Section: Introductionmentioning

confidence: 99%

Fast determination of antibiotics in whole blood

Chen

Andersson

Mecklenburg³

et al. 2013

Clinical Microbiology and Infection

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There is a need for analytical methods capable of monitoring blood antibiotic levels in real time. Here we present a method for quantifying antibiotic levels in whole blood that does not require any sample pretreatment. The tests employ the enzyme penicillinase to assay for penicillin G, penicillin V and ampicillin using a flow-injected biosensor, the Enzyme Thermistor. Optimal flow rates, sample volumes and pH were determined to be 0.5 mL/min, 100 μL and 7.0, respectively. Analysis of the antibiotics diluted in buffer gave a linear range of 0.17-5.0 mM. Calibration curves prepared using blood spiked with the antibiotics gave a linear range of 0.17-2.0 mM. Linear regression values for all of the calibration curves were 0.998 or higher. Assay cycle time was 5 min. The relative standard deviation value for 100 determinations of a mock blood sample spiked with penicillin G was 6.71%. Despite the elimination of sample pretreatment, no detectable clogging or signal drift was observed. The assay provides a fast, simple, reliable analytical method for determining antibiotic concentrations in blood without the need for any sample pretreatment. This is an important first step towards developing a device capable of real-time monitoring of antibiotic levels in whole blood. The technology has the potential to significantly improve the outcomes of patients undergoing critical care.

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“…Our group has focused on developing biosensors that employ thermal transduction to directly detect the thermal signal generated during enzyme catalysis. The instrument, the enzyme thermistor (ET), has been used to develop a wide range of assays (Xie and Danielsson, 2007). Recently we have shown that the device is capable of quantifying antibiotics in whole blood without any sample pretreatment (Chen et al, 2013).…”

Section: Introductionmentioning

confidence: 99%