Figure 5

a Test paper for the detection of rifampicin after modification (A) with BSA-Au NCs under UV light. The tenfold diluted urine samples with original rifampicin concentrations are as follows: (B) 0.5 µg/mL (fluorescence quenching ratio = 91% ± 1); (C) 5 µg/mL (82% ± 1.1); (D) 10 µg/mL (81% ± 1.8); (E) 30 µg/mL (79% ± 3.4); (F) 50 µg/mL (78% ± 1.7); (G) 100 µg/mL (75% ± 0.3); (H) 500 µg/mL(73% ± 1.9); and (I) 1000 µg/mL(69% ± 1.1). b Change in the fluorescence quenching ratio of the embedded BSA-Au NCs versus rifampicin concentration on the paper sensor (each data point represents an average of three separate studies (n = 3) in three different wax-printed 96-microplate paper platforms; three measurements were taken in each micro-well, and the error bars denote the standard deviation of the reading).