Label-Free Chemiresistive Immunosensors for Viruses

• Published in: Environmental science & technology Vol. 44; no. 23; pp. 9030 - 9035
• Main Authors: Shirale, Dhammanand J, Bangar, Mangesh A, Park, Miso, Yates, Marylynn V, Chen, Wilfred, Myung, Nosang V, Mulchandani, Ashok
• Format: Journal Article
• Language: English
• Published: Washington, DC American Chemical Society 01.12.2010
• Subjects: Aluminum Oxide - chemistry; Bacteriophage T7 - chemistry; Biological and medical sciences; Biosensing Techniques - instrumentation; Biosensing Techniques - methods; Biosensors; Biotechnology; Electrocatalysis; Electrochemical Techniques; Electrodes; Environmental Measurements Methods; Environmental monitoring; Environmental Monitoring - methods; Fundamental and applied biological sciences. Psychology; Immunologic Techniques - instrumentation; Immunologic Techniques - mortality; Levivirus - chemistry; Methods. Procedures. Technologies; Models, Biological; Nanowires; Nanowires - chemistry; Nanowires - virology; Polymers - chemistry; Pyrroles - chemistry; Runoff; Various methods and equipments; Viruses; Viruses - chemistry; Viruses - isolation & purification; Water Microbiology; Water Pollutants - chemistry; Water Pollutants - isolation & purification; Virus; Sensitivity resistance; Biosensor; Immunosensor
• ISSN: 0013-936X; 1520-5851
• DOI: 10.1021/es102129d

We report development, characterization, and testing of chemiresistive immunosensors based on single polypyrrole (Ppy) nanowire for highly sensitive, specific, label free, and direct detection of viruses. Bacteriophages T7 and MS2 were used as safe models for viruses for demonstration. Ppy nanowires were electrochemically polymerized into alumina template, and single nanowire based devices were assembled on a pair of gold electrodes by ac dielectrophoretic alignment and anchored using maskless electrodeposition. Anti-T7 or anti-MS2 antibodies were immobilized on single Ppy nanowire using EDC-NHS chemistry to fabricate nanobiosensor for the detection of corresponding bacteriophage. The biosensors showed excellent sensitivity with a lower detection limit of 10−3 plaque forming unit (PFU) in 10 mM phosphate buffer, wide dynamic range and excellent selectivity. The immunosensors were successfully applied for the detection of phages in spiked untreated urban runoff water samples. The results show the potential of these sensors in health care, environmental monitoring, food safety and homeland security for sensitive, specific, rapid, and affordable detection of bioagents/pathogens.