The optical biosensor consisting of a glutathione-S-transferase (GST)-immobilized gel film was developed to detect captan in contaminated water. The sensing scheme was based on the decrease of yellow product, s-(2,4-dinitrobenzene) glutathione, produced from substrates, 1-chloro-2,4-dinitrobenzene (CDNB) and glutathione (GSH), due to the inhibition of GST reaction by captan. Absorbance of the product as the output of enzyme reaction was detected and the light was guided through the optical fibers. The enzyme reactor of the sensor system was fabricated by the gel entrapment technique for the immobilized GST film. The immobilized GST had the maximum activity at pH 6.5. The optimal concentrations of substrates were determined with 1 mM for both of CDNB and GSH. The optimum concentration of enzyme was also determined with 100 microg/ml. The activity of immobilized enzyme was fairly sustained during 30 days. The proposed biosensor could successfully detect the captan up to 2 ppm and the response time to steady signal was about 15 min.
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http://dx.doi.org/10.1016/s0956-5663(03)00124-6 | DOI Listing |
Sci Rep
January 2025
Department of Chemistry, Amrita School of Physical Sciences Coimbatore, Amrita Vishwa Vidyapeetham, Coimbatore, India.
Carbon dots doped with metals and non-metals have gained much popularity due to the enhancement in their optical and electronic properties. In this study, polyethyleneimine-functionalized transition metal (nickel or copper) doped carbon dots (CD, NiCD and CuCD) were synthesized through hydrothermal method. The carbon dots exhibited a blue fluorescence at 470 nm when excited at 350 nm.
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March 2025
College of Chemistry and Environment, Southwest Minzu University, Chengdu, Sichuan 610225, China; Key Laboratory of Fundamental Chemistry of the State Ethnic Commission, College of Chemistry and Environment, Southwest Minzu University, Chengdu, Sichuan 610225, China. Electronic address:
Cholesterol (CHO) is an essential lipid in cell membranes and a precursor for vital living substances. Abnormal CHO levels can cause cardiovascular diseases. Therefore, simple and accurate monitoring of CHO levels is crucial for early diagnosis and effective management of cardiovascular diseases.
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January 2025
Laboratory for Electrical Instrumentation and Embedded Systems, IMTEK - Department of Microsystems Engineering, University of Freiburg, Georges-Köhler-Allee 103, 79110 Freiburg, Germany.
Cell cultures, organs-on-chip and microphysiological systems become increasingly relevant as models, , in drug development, disease modelling, toxicology or cancer research. It has been underlined repeatedly that culture conditions and metabolic cues have a strong or even essential influence on the reproducibility and validity of such experiments but are often not appropriately measured or controlled. Here we review microsensor systems for cell metabolism for the continuous measurement of culture conditions in microfluidic and lab-on-chip platforms.
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December 2024
Department of Chemistry, University of Patras, GR26504 Patras, Greece.
Liquid biopsy is an efficient diagnostic/prognostic tool for tumor-derived component detection in peripheral circulation and other body fluids. The rapid assessment of liquid biopsy techniques facilitates early cancer diagnosis and prognosis. Early and precise detection of tumor biomarkers provides crucial information about the tumor that guides clinicians towards effective personalized medicine.
View Article and Find Full Text PDFMicromachines (Basel)
December 2024
BioNano Applications Research Center, Gachon University, 1342 Seongnam-daero, Sujeong-gu, Seongnam-si 13120, Gyeonggi-do, Republic of Korea.
The increased demand for consuming seafood has made seafood production undergo a rapid period of growth. However, seafood has a high risk of contamination from harmful microorganisms and marine toxins which can cause health problems for humans consuming it. Concerning this issue, monitoring seafood safety has become a center of attention for researchers, and developing effective methods for detecting contamination in seafood has become a critical research field.
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