Alpha se spectroscopic ellipsometer

A silicon wafer (~11x13 mm) was treated with 0.1 M NaOH for 1 min at 80 °C and washed three times with water. The resulting Si wafer was coated with alternating layers of PAMAM and hyperbranched alginate, with or without a fluorescein label. After each layer, excess polymer was removed via three washes with MOPS buffer, water, and ethanol, and dried via argon. Surface film thickness was measured via J. A. Woollam Co. alpha-SE spectroscopic ellipsometer, at a 70^° angle and standard mode settings, using the transparent film data model. Three readings were collected for each data point.

A silicon wafer (~11×13 mm) was treated with 0.1 M NaOH for 1 min at 80 ᴼC and washed three times with water. The resulting Si wafer was coated with 12 alternating layers of CONP dispersion and alginate (both solutions at 3 mg/ml in MOPS buffer; 30 sec per incubation at room temperature), starting with CONP as the base layer. Control wafers were exposed to alginate only. After each coating, excess CONP or alginate was washed three times with MOPS buffer, water, ethanol, and blow-dried with argon. Surface film thickness was measured via J. A. Woollam Co. alpha-SE spectroscopic ellipsometer, at a 70ᴼ angle and standard mode settings, using the transparent film data model. Three readings were collected for each data point.