One Chip = Triplicate Measurements + Reference
The P4SPR provides simultaneous real-time information about binding events in each of the four channels for fast and reliable data. The sample is injected into its own injection port that feed the "S" shaped SPR sample channels (Figure 1. top part) while the reference solution is injected into another port to fill the single channel (Figure 1. bottom part). Each SPR channel has its own light source to monitor independently SPR signals over the time course of an experiment. Therefore, the output sample data is reference-corrected for temperature, refractive index and nonspecific binding variations to generate high quality target-specific signal.
The analytical performances were determined with manual injections of saline solutions between 1.33 RI unit and 1.40 RI unit flowed into the sample channel and water in the reference channel. Figure 2 shows the reference-corrected time course for the three sample channels. Four solutions of increasing RI unit produced SPR signal plateaus demonstrating the system's sensitivity over 2700 nm/RI with a high R2 0.999 over the titration range and an across-channel coefficient of variation between 0.6 to 8% with a repeatability of 0.4% (6.02 ± 0.02). Moreover, repeated exposure to a single solution (2.1 g of NaCl / 100 mL water) generated a very similar SPR response across the time course. These data demonstrate that manual sample injections with the compact P4SPR provides excellent sensitivity and repeatability across all sample channels.