The viability of the 'dual-affinity' 40 nm FluoroPerAuNPs was further studied by observing the stability and performance of these particles in the presence of disulfide linker cleavage reagents. The incorporation of thiol-based reducing reagents, such as dithiothreitol (DTT), presented potential off-target consequences within assay reagents, such as protein denaturation and undesirable thiol-gold bond formation on the particle surface. To mimic the proposed assay workflow, FluoroPerAuNPs were pre-mixed with DTT at pH 10 prior to detection using anti-FITC pAb printed test strips. This format enabled us to primarily assess particle stability but also the retention of functionality of test line itself while challenged to exposure to the cleavage mixture over a prolonged 10-minute period. No notable losses in signal intensity -compared to a negative DTT control -was observed when measuring test line signal (Figure ). Whilst the reduction of structural elementssuch as antibody disulfide bridges -cannot be ruled out, these results echo findings by Shlyapnikov et al. who utilised reducing conditions to cleave disulfide-linked hydrophobic blocking agents from the surface of microarray-based immunoassays. Authors noted that no significant effect on antibody binding after a 5-minute incubation period in cleavage reagent, offering similar insights into the robustness of recognition components under reducing conditions within brief assay timeframes. FITC pAbs and PSA, respectively. Data was collected in triplicate and was fitted using a 4-parameter logistic (4PL) regression fit. f. The mean signal intensity (N = 3) of anti-FITC test lines where 40 nm FluoroPerAuNPs were directly mixed with DTT in cleavage conditions prior to running.