9000f mark 2 scanner

The assay was performed at room temperature. The test strip with a conjugate pad was vertically submerged in the tested sample for 1.5 min before it was removed and placed on a horizontal surface.
For test strips with pre-mixing, we carried out two different experiments. First, the test strips were dipped into wells with a sample volume of 64 µL, and then mixed with 6 µL of GNP conjugate (OD₅₂₀ = 4). Second, the test strips were dipped into wells containing only the sample. After a period of eight minutes, when all of the liquid was transported through capillary movement in the nitrocellulose membrane, we removed the test strips and dipped them in a solution with the GNP conjugate (70 µL, OD₅₂₀ = 0.32).
The formations of the colored zones were visually detected 10 min after the test strips were immersed. The visual LOD of the LFIA was defined by PVY concentration when the test line appeared. In the quantitative analysis, the test strips were scanned using a Canon 9000F Mark II scanner (Canon, Tokyo, Japan), and the digital images were analyzed using a TotalLab TL120 software (Nonlinear Dynamics, Newcastle upon Tyne, UK).

First, to ensure uniformity, we prepared a sufficient volume of bacterial samples (from 1 × 10² to 1 × 10⁸ CFU/mL) to be used for all experiments. For one LFIA test strip, a specific volume of nanoparticle label was mixed to 100 µL of bacterial solution in PBST. MPs were added from 3 to 20 µL, LPs were added from 0.5 to 20 µL, Au NPs were added from 3 to 10 µL, and Au@Pt NPs were added from 1 to 10 µL. Then, test strips were dipped, and results were analysed after 20 min. Afterwards, the results were visible by the naked eye and test strips were scanned using a Canon 9000F Mark II scanner (Canon, Tokyo, Japan). Then, the obtained digital data were processed using TotalLab TL120 (Nonlinear Dynamics, Newcastle, UK) to obtain the values of colour intensities in the test zones of test strips. The quantitative dependences of colour intensity from bacterial cell concentration were plotted using OriginPro 9.0 software (Origin Lab, Northampton, MA, USA). The three-sigma method was used to determine the detection limit.