Towards a Dual Lateral Flow Nanobiosensor for Simultaneous Detection of Virus Genotype-Specific PCR Products

Figure 1

Principle of the dual nanoparticle-based lateral flow biosensor for simultaneous detection of nodavirus SJNNV and RGNNV genotypes. Two test zones (anti-fluorescein antibody (TZ-R) and anti-digoxigenin antibody (TZ-S)) and a control zone (biotinylated BSA (CZ)) have been deposited on the diagnostic membrane. The sample, containing the respective genotype of the target analyte (tetra-primer PCR product with fluorescein (F) for RGNNV genotype or digoxigenin (D) for SJNNV genotype), is hybridized with a biotinylated genotype-specific oligonucleotide probe and applied on the conjugation pad, where functionalized gold nanoparticles (Au) with anti-biotin antibody have already been added. Following that, the biosensor is immersed in the developing buffer, the sample and the nanoparticles are immobilized on the appropriate test zone, and the positive signal is visible by the naked eye, as a red zone. The excess nanoparticles bind to the control zone of the biosensor. The image shows a side view of the lateral flow biosensor. IP: immersion pad; CP: conjugation pad; M: diagnostic membrane; AP: absorbent pad. The assay components are not in scale.