Immobilization Techniques and Integrated Signal Enhancement for POC Nanocolor Microfluidic Devices

Figure 4

Control experiments: protocols 3 and 4. (a) REA chip coated with streptavidin according to protocol 3 (left). 3-APTES-coated REA chip spotted with 2 mg/mL streptavidin solution and incubated at RT in a wet chamber for 17.5 h (right). Analyte detection was performed on both chips. AuNP-analyte complex binding capacity and the homogeneity of the binding were comparable. (b) REA chip coated with streptavidin according to protocol 4 (left). 3-APTES-coated REA chip spotted with 2 mg/mL streptavidin + 0.225% CMC in 0.01% Na-K-phosphate buffer, pH 7.0, and incubated at RT in a wet chamber for 30 min (right). Analyte detection was performed on both chips. The chip coated according to protocol 4 exhibited significantly higher AuNP-analyte complex binding.

(a)

(b)