Magnetic Fe3O4@TiO2 nanoparticles-based test strip immunosensing device for rapid detection of phosphorylated butyrylcholinesterase

• Published in: Biosensors & bioelectronics Vol. 50; pp. 486 - 491
• Main Authors: Ge, Xiaoxiao, Zhang, Weiying, Lin, Yuehe, Du, Dan
• Format: Journal Article
• Language: English
• Published: Kidlington Elsevier B.V 15.12.2013; Elsevier
• Subjects: Biological and medical sciences; Biomarker; Biosensing Techniques - economics; Biosensing Techniques - instrumentation; Biosensors; Biotechnology; Butyrylcholinesterase - analysis; Butyrylcholinesterase - blood; Fundamental and applied biological sciences. Psychology; Humans; Immunoassay - economics; Immunoassay - instrumentation; Immunosensor; Limit of Detection; Magnetics; Magnetite Nanoparticles - chemistry; Methods. Procedures. Technologies; Organophosphorous pesticides; Organophosphorus Compounds - analysis; Organophosphorus Compounds - blood; Pesticides - analysis; Pesticides - blood; Phosphorylated butyrylcholinesterase; Phosphorylation; Reagent Strips - analysis; Sensitivity and Specificity; Test strip; Titanium - chemistry; Various methods and equipments; Biomarker; Test strip; Phosphorylated butyrylcholinesterase; Immunosensor; Organophosphorous pesticides; Nanoparticle; Device; Pesticides; Biological marker; Rapid technique; Magnetic; Biosensor; Detection
• ISSN: 0956-5663; 1873-4235
• DOI: 10.1016/j.bios.2013.07.017

An integrated magnetic nanoparticles-based test strip immunosensing device was developed for rapid and sensitive quantification of phosphorylated butyrylcholinesterase (BChE), the biomarker of exposure to organophosphorous pesticides (OP), in human plasma. In order to overcome the difficulty in scarce availability of OP-specific antibody, here magnetic Fe3O4@TiO2 nanoparticles were used and adsorbed on the test strip through a small magnet inserted in the device to capture target OP–BChE through selective binding between TiO2 and OP moiety. Further recognition was completed by horseradish peroxidase (HRP) and anti-BChE antibody (Ab) co-immobilized gold nanoparticles (GNPs). Their strong affinities among Fe3O4@TiO2, OP–BChE and HRP/Ab-GNPs were characterized by quartz crystal microbalance (QCM), surface plasmon resonance (SPR) and square wave voltammetry (SWV) measurements. After cutting off from test strip, the resulted immunocomplex (HRP/Ab-GNPs/OP–BChE/Fe3O4@TiO2) was measured by SWV using a screen printed electrode under the test zone. Greatly enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio, which amplifies electrocatalytic signal significantly. Moreover, the use of test strip for fast immunoreactions reduces analytical time remarkably. Under the optimized conditions, the developed device shows a broader linear response over the concentration of OP–BChE from 0.05nM to 10nM within 15min, with a detection limit of 0.01nM. Coupling with a portable electrochemical detector, the integrated device with advanced nanotechnology displays great promise for sensitive, rapid and on-site evaluation of OP poisoning. •An integrated magnetic nanoparticles-based test-strip immunosensing device was developed.•Fe3O4@TiO2 nanoparticles overcome the difficulty in unavailability of OP-specific antibody.•Enhanced sensitivity was achieved by introduction of GNPs to link enzyme and antibody at high ratio.•The immunosensor was used to detect phosphorylated butyrylcholinesterase in human plasma.