Filtration, adsorption and immunodetection of virus using polyelectrolyte multilayer-modified paper

A new method for detection of viruses has been developed. The entire assay can be performed within 2 h, and consists of a polyelectrolyte-multilayer-modified cellulosic filter paper combined with immunodetection. The M13 bacteriophage was used as a model virus. A visual colour-based detection system, anti-M13 horseradish peroxidase (HRP) conjugate and 3,3′,5,5′-tetramethylbenzidine (TMB), was selected to allow semi-quantitative assessment by human eye, or quantitative assessment using a digital scanner. By filtering a volume of 0.50 ml, it was possible to visually detect a concentration of 106 pfu/ml. The detection limit was improved to 5 × 104 pfu/ml by increasing the volume of the sample to 100 ml. For comparison, it was only possible to detect a concentration of 107 pfu/ml using conventional sandwich enzyme-linked immunosorbent assay (ELISA) with the same detection system.

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► A rapid paper-based immunodetection method for viruses in water has been developed.
► Virus adsorption to the paper was significantly enhanced by adsorbing polyelectrolyte multilayers (PEMs) onto filter papers prior to filtration of virus suspensions.
► The use of PEMs in combination with casein blocking reduced non-specific binding to a minimum.
► The assay performs as well as, or even better than, conventional ELISA based on the same detection system. The lowest concentration detected being 5 × 104 pfu/ml.