nir-vana innovation network

The performance of lateral flow immunosensors is restricted by their rigid 2D design. 3D Paper-based analytical devices can overcome this problem and enable new features such as the detection of many target molecules simultaneously or the reduction of manufacturing costs. However, it is difficult to store reagents such as nanoparticles in devices made solely of paper.

A research team from a Spanish health institution specialized in biosensors for molecular diagnostics has patented a technology that solves this problem. Their immunosensors contain reservoirs for storing antibody-decorated nanoparticles in the same filter paper. Folding the paper allows the easy transfer of reagents to different parts of the test without using pumps or syringes.

The specific capture of the target molecule or pathogen generates colored spots thanks to the excellent optical properties of gold nanoparticles. The colored spots can be detected with companion of apps for android, also developed by the research team. The apps only require hovering a smartphone over the assay to quantify the color in real time.

Prototypes for the detection of the cytokine IL-6 at clinically relevant concentrations in blood and in less than 17 minutes have been demonstrated. Disposable tests for detecting urine infections by E. coli in less than 7 minutes have also been developed.

The Rapid Diagnostic Tests (RDTs) developed are easily adaptable to other targets by tuning biosensor design.

Companies interested in the development of novel point-of-care diagnostic devices who wish to commercialize the technology via license agreement, or R&D institutions providing technical cooperation for the development of specific immunosensors are being sought.

Advantages & innovations

The paper biosensors are light, compact and disposable and can be used to detect analytes in complex matrices such as blood or urine. Cheaper. Biosensors made from a single piece of conventional paper reduce manufacturing costs compared to current lateral flow immunoassays, which are made of multiple materials. Versatile design. The design is compatible with 3D microfluidic schemes on folded paper, which are more versatile than 2D lateral flow tests. High throughput. Easy fabrication of sensor arrays with limitless sensing points in the same paper device. Long shelf life. Gold nanoparticles in paper reservoirs create intense signals without the strict storage requirements of enzymes (no noticeable loss of activity after 1 month stored at room temperature with the patented method for paper-based nanoparticle reservoirs). Fast and sensitive. Pieces of filter paper incorporating antibody-modified nanoparticles have been used to detect bacteria (E. coli) in urine at concentrations above the clinical infectious threshold with an assay time under 7 minutes. Interleukin 6 (IL-6) has been detected with an ultralow limit of detection of 0.1 pg mL-1 with a 17 minutes long procedure thanks to the proposed paper-based biosensor technology. Modular. The biosensor design is easily adaptable to customer and end-users needs.

Stage of development

Prototype available for demonstration

Partner sought

Type: industrial partners for developing and commercializing products based on the technology and R&D institutions for developing customised immunosensors. Field of activity: the research team is looking for companies and/or R&D institutions in the health care sector, willing to develop point-of-care (POC) diagnostic devices based on paper, suitable for preliminary or emergency medical screening and for use in medical facilities with limited resources. A potential partner could be interested, especially, in the detection of bacteria in urine or protein biomarkers in serum or blood. Role of partner: License agreement - to commercialize products based on the patented technology worldwide. Technical cooperation agreement – to provide technical support for developing specific immunosensors that could be designed, due to the wide range of analytes that can be detected.