We describe a kinetic colorimetric method for assaying lipase (EC 3.1.1.3) activity in serum by using a natural long-chain fatty acid 1,2-diglyceride. In the presence of colipase, deoxycholate, and calcium ions, pancreatic lipase hydrolyzes the clear substrate solution to produce a 2-monoglyceride, which in turn releases glycerol by the action of a 2-monoglyceride lipase. Glycerol is then assayed by a sequence of enzymatic actions (glycerol kinase, glycerol phosphate oxidase, and peroxidase) that produce a violet quinone monoimine dye with peak absorption at 550 nm. The method features zero-order reaction kinetics, provides a simple and rapid assay with an extended dynamic range, is specific and precise, gives results that correlate well (r greater than or equal to 0.99) with those of methods in which emulsified triolein is the substrate, and lends itself readily to automation. For all these reasons, the method seems highly suitable for routine use in clinical laboratories.
Download full-text PDF |
Source |
|---|
Publication Analysis
Top Keywords
Similar Publications
Confined active area and aggregation kinetic-based AuNPs@PVP nanosensors for simultaneous colorimetric detection of cysteine and homocysteine as homologues in human urine and serum.
Mikrochim Acta
January 2025
College of Chemistry, Chemical Engineering & Environmental Science, Minnan Normal University, Zhangzhou, 363000, China.
The detection of cysteine (Cys) and homocysteine (Hcy) in biological fluids has great significance for early diagnosis, including Alzheimer's and Parkinson's disease. The simultaneous determination of Cys and Hcy with a single probe is still a huge challenge. To enlarge the differences in space structure (line and ring) and energy (-721.
View Article and Find Full Text PDFA Microfluidic Paper-Based Device for Monitoring Urease Activity in Saliva.
Biosensors (Basel)
January 2025
CBQF-Centro de Biotecnologia e Química Fina, Laboratório Associado, Universidade Católica Portuguesa, Escola Superior de Biotecnologia, Rua Diogo Botelho 1327, 4169-005 Porto, Portugal.
Chronic Kidney Disease (CKD) is a disorder that affects over 10% of the global population, and that would benefit from innovative methodologies that would provide early detection. Since it has been reported that there are high levels of urease in CKD patients' saliva, this sample is a promising non-invasive alternative to blood for CKD detection and monitoring. This work introduces a novel 3D µPAD for quantifying urease activity in saliva in a range of 0.
View Article and Find Full Text PDFFluorogenic Biosensing with Tunable Polydiacetylene Vesicles.
Biosensors (Basel)
January 2025
Department of Chemical Engineering, University of California Davis, Davis, CA 95616, USA.
Polydiacetylenes (PDAs) are conjugated polymers that are well known for their colorimetric transition from blue to red with the application of energetic stimulus. Sensing platforms based on polymerized diacetylene surfactant vesicles and other structures have been widely demonstrated for various colorimetric biosensing applications. Although less studied and utilized, the transition also results in a change from a non-fluorescent to a highly fluorescent state, making polydiacetylenes useful for both colorimetric and fluorogenic sensing applications.
View Article and Find Full Text PDFIron/phosphorus co-doped carbon nanozyme for colorimetric sensing of organophosphorus pesticides in food.
Anal Methods
January 2025
Chongqing Key Laboratory of New Energy Storage Materials and Devices, School of Science, Chongqing University of Technology, Chongqing 400054, P. R. China.
In this work, a peroxidase-like (POD-like) nanozyme of Fe/P-NC was synthesized by doping phosphorus (P) and nitrogen (N) to manipulate iron (Fe) activity centers, which showed catalytic activity and kinetics comparable to those of natural HRP. Based on the efficient POD-like activity of the Fe/P-NC nanozyme and cascaded catalytic reactions with acetylcholinesterase (AChE), we constructed a colorimetric, affordable and sensitive sensing platform to detect organophosphorus pesticides (OPs). In the presence of AChE, the POD-like activity of the prepared Fe/P-NC was suppressed, which weakened the Fe/P-NC-catalyzed oxidation of TMB.
View Article and Find Full Text PDFCRISPR-associated Plasmonic Colorimeter Method (Ca-PCM): A real-time RGB detection system for gold nanoparticles-based nucleic acid biosensors.
Anal Chim Acta
February 2025
Fundación IMDEA Nanociencia, Madrid, Spain; Division of Hematopoietic Innovative Therapies, Innovative Therapies Unit. Centro de Investigaciones Energéticas, Medioambientales y Tecnológicas (CIEMAT), 28040, Madrid, Spain; Advanced Therapies Unit, Instituto de Investigación Sanitaria Fundación Jiménez Díaz (IIS-FJD, UAM), 28040, Madrid, Spain. Electronic address:
Background: The detection of genetic sequences represents the gold standard procedure for species discrimination, genetic characterisation of tumours, and identification of pathogens. The development of new molecular detection methods, accessible and cost effective, is of great relevance. Biosensors based on plasmonic nanoparticles, such as gold nanoparticles (AuNPs), provide a powerful and versatile platform for highly sensitive, economic, user-friendly and label-free sensing.
View Article and Find Full Text PDFWant AI Summaries of new PubMed Abstracts delivered to your In-box?
Enter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!