A combination of magnetic permeability detection with nanometer-scaled superparamagnetic tracer and its application for one-step detection of human urinary albumin in undiluted urine.
TL;DR: A rapid (6.5 min) and simple one-step magnetic immunoassay (MIA) has been developed for analysis of human urinary albumin in near patient settings and the obtained results showed good correlation with the hospital immunoturbidimetric reference method.
About: This article is published in Biosensors and Bioelectronics.The article was published on 2006-06-15. It has received 29 citations till now. The article focuses on the topics: Magnetic immunoassay.
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TL;DR: The applications of magnetic microbeads in biosensors and bio-bar code assays allow the detection at very low concentration of biological molecules, similar to PCR sensitivity.
Abstract: This review paper reports the applications of magnetic microbeads in biosensors and bio-bar code assays. Affinity biosensors are presented through different types of transducing systems: electrochemical, piezo electric or magnetic ones, applied to immunodetection and genodetection. Enzymatic biosensors are based on biofunctionalization through magnetic microbeads of a transducer, more often amperometric, potentiometric or conductimetric. The bio-bar code assays relie on a sandwich structure based on specific biological interaction of a magnetic microbead and a nanoparticle with a defined biological molecule. The magnetic particle allows the separation of the reacted target molecules from unreacted ones. The nanoparticles aim at the amplification and the detection of the target molecule. The bio-bar code assays allow the detection at very low concentration of biological molecules, similar to PCR sensitivity.
116 citations
TL;DR: The theoretical and experimental results suggest that the magnetoimpedance sensors are particularly suitable for highly sensitive detection of low-concentration biomolecules, and might be used for early diagnosis and screening of cancers.
89 citations
Cites methods from "A combination of magnetic permeabil..."
...Since then, Resonant coil sensor (Lu et al., 2006; Richardson et al., 2001; Stevenson et al., 2005), Fluxgate sensor (Heim et al., 2009; Ludwig et al., 2005a; Ludwig et al., 2005b), Hall sensor (Besse et al., 2002; Ejsing et al., 2004; Østerberg et al., 2009; Lee et al., 2009; Manzin et al., 2012;…...
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TL;DR: This review focuses on homogeneous biosensors for the in vitro detection of biomarkers and discriminates the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection.
Abstract: The growing availability of biomarker panels for molecular diagnostics is leading to an increasing need for fast and sensitive biosensing technologies that are applicable to point-of-care testing. In that regard, homogeneous measurement principles are especially relevant as they usually do not require extensive sample preparation procedures, thus reducing the total analysis time and maximizing ease-of-use. In this review, we focus on homogeneous biosensors for the in vitro detection of biomarkers. Within this broad range of biosensors, we concentrate on methods that apply magnetic particle labels. The advantage of such methods lies in the added possibility to manipulate the particle labels by applied magnetic fields, which can be exploited, for example, to decrease incubation times or to enhance the signal-to-noise-ratio of the measurement signal by applying frequency-selective detection. In our review, we discriminate the corresponding methods based on the nature of the acquired measurement signal, which can either be based on magnetic or optical detection. The underlying measurement principles of the different techniques are discussed, and biosensing examples for all techniques are reported, thereby demonstrating the broad applicability of homogeneous in vitro biosensing based on magnetic particle label actuation.
82 citations
Cites background or result from "A combination of magnetic permeabil..."
...Albumin in urine serves as a protein biomarker for diabetes and hypertension patients who have a higher risk for developing a nephropathy [108]....
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...Comparisons with the results of a turbidimetric immunoassay that serves as the hospital’s reference method show a good correlation with the magnetic permeability measurement results [108]....
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TL;DR: This review focuses on the instrumental quantification of proteins (the most of all albumin) in human urine matrix, which is a powerful tool for the discovery and the analysis of biomarkers in urine, however, costs of the analysis are high, especially for quantitative analysis.
67 citations
TL;DR: In this paper, a microfluidic device for the determination of the concentration of magnetic beads under continuous flow of the carrier fluid by means of the giant magneto-impedance effect (GMI) was described.
Abstract: We describe a microfluidic device for the determination of the concentration of magnetic beads under continuous flow of the carrier fluid by means of the Giant Magneto-Impedance effect (GMI). The microfluidic chip is composed of a 10 μl chamber situated on top of the GMI sensing material, which is inserted in a microstrip transmission line for the impedance measurements. Two different GMI materials have been used for the experiments: an amorphous ribbon and a permalloy based multilayer, sputtered onto the same polymeric material of the microfluidic chamber. Detection tests in continuous flow have been performed using solutions containing two types of beads: one made of ferromagnetic microparticles and the other made of superparamagnetic nanoparticles. A basic calculation of the magnitude of the fringe field created by the beads assures a detectable signal on the sensors, but the experimental difficulties severely condition the measurements. The results show a promising sensitivity for both types of particles but also reveal an important number of detection problems that must be overcame before the prototype become functional.
57 citations
References
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TL;DR: In this paper, the authors developed a strategy to develop programmes for all patients with diabetes, focused on early detection of renal disease followed by intervention, to prevent the development of end-stage renal failure.
550 citations
549 citations
TL;DR: Evidence is provided that the loosening of the HSA structure in the N-F transition takes place primarily in HSA-DOM III and that HSA -DOM I undergoes a structural rearrangement with only minor changes in secondary structure, whereas Hsa-DOM II transforms to a molten globule-like state as the pH is reduced.
434 citations
TL;DR: The demonstration that microalbuminuria is predictive of overt diabetic nephropathy has created a demand for the routine measurement of urinary albumin in diabetic patients and recommendations for the standardization of assays are given.
Abstract: The demonstration that microalbuminuria is predictive of overt diabetic nephropathy has created a demand for the routine measurement of urinary albumin in diabetic patients.' The first part of this report provides a brief overview of microalbuminuria in diabetes mellitus. The second defines assay performance criteria and sample handling conditions for the measurement of urinary albumin and gives recommendations for the standardization of assays and includes an assessment of selected immunochemical methods.
224 citations
TL;DR: The sensitivity, accuracy, and reproducibility of the FIA for measuring UAE in normal subjects are reported, which are more sensitive than radial immunodiffusion methods and has been shown to accurately measure human albumin and immunoglobulin levels in saliva.
127 citations