Whole-cell luminescent bioreporter sensors based on immobilized recombinant Escherichia coli are described and evaluated. The sensors were prepared by glutaraldehyde-anchoring of nonspecific anti-E. coli antibodies on aminosylilated gold or silica glass surfaces with subsequent attachment of the probe bacteria. We demonstrate the generality of the concept by attachment of several E. coli strains that express luciferase in response to different physiological stress conditions including heat shock, DNA damage (SOS), fatty acid availability, peroxide and oxidative stress. The sensors can be used either as single- or multiple-use disposable sensing elements or for continuous operation. We show compatibility with optical fiber technology. Storage stability of the sensors exceeded 5 months with no measurable deterioration of the signal. Repeatability on exposure in successive days was <15%, as was sensor to sensor reproducibility. Sensitivity and detection limits of the immobilized cells were comparable to that of non-immobilized bacteria.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1016/s0039-9140(01)00533-1 | DOI Listing |
ACS Appl Mater Interfaces
January 2025
School of Biomedical Sciences and Engineering, South China University of Technology, Guangzhou International Campus, Guangzhou 511442, P. R. China.
T-cell-engaging bispecific antibodies (BiTEs), which can simultaneously bind to antigens on tumor cells and T cells, show good potential in cancer immunotherapy. A practical and feasible approach for emulating BiTEs involves immobilizing two types of monoclonal antibodies (mAbs) onto a single nanoparticle; however, this approach involves complex immobilization processes and chemical reactions. To overcome these challenges, we achieved gentle antibody immobilization through receptor-ligand interactions by constructing a mAb delivery system known as Fcγ receptor 1 (FcγR1)-expressing cell membrane-coated nanoparticles (abbreviated as FcγR1-CMNPs).
View Article and Find Full Text PDFAnalyst
December 2024
Central Laboratory, Chongqing University FuLing Hospital, Chongqing, 408099, China.
Cardiovascular disease, intimately linked to dyslipidemia, is one of the leading global causes of mortality. Dyslipidaemia often presents as an elevated concentration of low-density lipoprotein (LDL) and a decreased concentration of high-density lipoprotein (HDL). Therefore, accurately measuring the levels of LDL and HDL particles is crucial for assessing the risk of developing cardiovascular diseases.
View Article and Find Full Text PDFAnal Chem
December 2024
Department of Entomology and Nematology and UCD Comprehensive Cancer Center, University of California, Davis, California 95616, United States.
The microsomal epoxide hydrolase (mEH) is important in the detoxification of carcinogens in the liver and other tissues but is also a blood biomarker of hepatitis and liver cancer. Improved analytical methods are needed for the study of its role in the metabolism of xenobiotics and endogenous roles as a blood biomarker of diseases. The development of a double nanobody sandwich ELISA offers significant improvements over traditional polyclonal or monoclonal antibody-based assays, enhancing both the homogeneity and the stability of assay production.
View Article and Find Full Text PDFBiosens Bioelectron
January 2025
BioMark@UC/CEMMPRE-ARISE, Department of Chemical Engineering, Faculty of Sciences and Technology, University of Coimbra, Coimbra, Portugal. Electronic address:
Aggregation of alpha-synuclein (aSyn) occurs in presynaptic neurons and constitutes a key factor for the progression of Parkinson's disease, emphasising the urgency of early detection to support effective treatment. Unfortunately, a reliable, sensitive and cost-effective diagnostic tool has so far been lacking. Thus, this work presents a novel biosensor for detecting aSyn using plastic antibodies coupled to electrochemical detection.
View Article and Find Full Text PDFFront Allergy
July 2024
Division of Allergy and Immunology, Department of Medicine, Johns Hopkins University School of Medicine, Baltimore, MD, United States.
In the United States, 19 allergen extracts of different specificities are standardized, which means that their potencies are determined in comparison to a US reference standard. For cat allergen extracts, potency is determined by measuring Fel d 1 content expressed in in Fel d 1 units, and with a unitage that correlates with skin test reactions (bioequivalent allergy units or BAU). Currently, Fel d 1 content is measured with a radial immunodiffusion (RID) assay that uses polyclonal sheep antisera to detect the allergenic protein by producing a white precipitin line in agar gel.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!