Sensitive detection of atrazine in tap water using TELISA

Bülow

2018

J Therm Anal Calorim

Self Cite

A broad measurement range of glucose is often required in clinical analysis, especially for diabetic patients where glucose levels can be very high. Pyrroloquinoline quinone glucose dehydrogenase (PQQGDH) has previously been used in electrochemical quantification of glucose with an extended linear range. However, in real sample determination of glucose, interferences from electroactive substances in blood are unavoidable. Calorimetric biosensors, e.g., the Enzyme Thermistor, are insensitive to either directly electroactive or optical interferences often present in real clinical samples. This paper describes a novel analytical strategy where the intrinsic advantages of PQQGDH are combined with the Enzyme Thermistor as biosensor using calorimetric detection as general measurement principle. When compared with the most frequently used enzyme glucose oxidase, PQQGDH has a higher catalytic efficiency and is insensitive to the availability of oxygen. The use of calorimetry in this context resulted in a broad linear range of glucose measurements, from 0.009 to 100 mM, an excellent specificity and insignificant side effects of compounds present in blood at high concentrations, such as lactate and urea.

Section: Introductionmentioning

confidence: 99%

Pyrroloquinoline quinone glucose dehydrogenase adopted in thermometric analysis for enhancement of glucose determination

Bülow

2018

J Therm Anal Calorim

Self Cite

“…The enzyme thermometric (ET) biosensor is capable of detecting changes in temperature caused by an enzyme-catalyzed reaction [16][17][18][19][20]. The temperature change is proportional to the molar concentration of the substrate [21,22].…”

Section: Introductionmentioning

confidence: 99%

Thermometric analysis of blood metabolites in ICU patients

Adlerberth

Meng

Mecklenburg³

et al. 2019

J Therm Anal Calorim

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Real-time monitoring of patient's blood metabolites, such as glucose and lactate, could potentially improve surgery and recovery outcomes for patients in surgical and intensive care units. Our enzyme thermometric biosensor which is based on flow injected calorimetric determination of immobilized enzyme reaction is capable of performing continuous, fast, and quantitative analysis of metabolites using whole blood. A key technical advantage the assay affords is the ability to use unpretreated whole blood. In this article, the enzyme thermometric biosensor was used, for the first time, to determine glucose and lactate concentrations in the blood of ICU patients. The linear detection range for glucose was 0.5-30 mM and 0.25-12 mM for lactate, using a 20 μL sample volume. A maximum sampling rate of 15 measurements per hour was achieved using venous blood samples, which corresponds to a 4-min measurement interval. In order to validate the accuracy of the results, a comparative analysis between the thermometric biosensor and the clinically applied instrument (LifeScan's OneTouch ®) which is based on disposable dry chemical reaction was performed using samples from 33 patients. The results showed a good correlation between the two methods for both glucose (r = 0.843, p < 0.0001) and lactate (r = 0.78, p = 0.0105). The ability to monitor metabolite levels and trends on a clinically relevant timescale of 5 min is critical for intensive monitoring of ICP and operative patients.

Journal of Electroanalytical Chemistry

“…Despite the fact that recent studies presented the evolution of ATR-degrading capabilities in the environment [13], the maximum residue level of ATR in water defined by the WHO (i.e. 0.1 μg/L) requires sensitive analytical tools such as immunoassay strategies for its fast and reliable detection [14][15][16]. The enzyme-linked immunosorbent assay (ELISA) relies on the inherent ability of an antibody (Ab) to bind to the specific structure of a molecule, most commonly in form of sandwich or competitive assays.…”

Section: Introductionmentioning

confidence: 99%

Inkjet-printed microtiter plates for portable electrochemical immunoassays

Jović

Zhu

Lesch

et al. 2017

Herein, we present the large-scale fabrication of multiplexed three-electrode sensors used in a point-of-care device platform that couples a magnetic bead-based immunoassay strategy with amperometric detection for rapid and highly sensitive analysis. The multiplexed sensors consisted of eight independent electrochemical cells, each with a carbon nanotube (CNT) working electrode, CNT counter electrode and a silver-silver chloride quasi-reference electrode. The microchips were fabricated on flexible polyethylene terephthalate (PET) sheets by sequential multilayer inkjet printing (IJP) of silver, CNT and insulator inks that were either simultaneously or subsequently post-processed (e.g. through UV photo-polymerization or photonic curing). Finally, plastic wells were mounted on top of the inkjet-printed patterns to obtain an eight-well microtiter plate where each well had a solution capacity of 50 μL. Due to the high precision of the IJP process, the microtiter plates showed high reproducibility among the individual electrochemical cells (1-2% of deviation). Furthermore, the microchips can be reusable for at least up to 20 times as demonstrated herein. In a customized multichannel potentiostat with eight implemented magnets matching the positions of the working electrodes, the electrochemical readout of magnetic bead based sandwich and competitive immunoassays was successfully realized for the detection of thyroid-stimulating hormone (TSH) and atrazine (ATR) in aqueous and urine samples, respectively. The achieved limits of detection for ATR (i.e. 0.01 μg/L) and TSH (i.e. 0.5 μIU/mL) demonstrated the potential of the IJP microtiter plates for the environmental and biological quantification of analytes in a very reliable high throughput platform. This work shows that IJP has certainly reached the status of a batch production tool for electroanalytical sensing platforms.